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+;;; yasnippet.el --- Yet another snippet extension for Emacs.
+
+;; Copyright (C) 2008-2018 Free Software Foundation, Inc.
+;; Authors: pluskid <pluskid@gmail.com>,
+;;          João Távora <joaotavora@gmail.com>,
+;;          Noam Postavsky <npostavs@gmail.com>
+;; Maintainer: Noam Postavsky <npostavs@gmail.com>
+;; Version: 0.13.0
+;; Package-Version: 20180620.1750
+;; X-URL: http://github.com/joaotavora/yasnippet
+;; Keywords: convenience, emulation
+;; URL: http://github.com/joaotavora/yasnippet
+;; Package-Requires: ((cl-lib "0.5"))
+;; EmacsWiki: YaSnippetMode
+
+;; This program is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+;;
+;;   Basic steps to setup:
+;;
+;;    (add-to-list 'load-path
+;;                 "~/path-to-yasnippet")
+;;    (require 'yasnippet)
+;;    (yas-global-mode 1)
+;;
+;;
+;;   Interesting variables are:
+;;
+;;       `yas-snippet-dirs'
+;;
+;;           The directory where user-created snippets are to be
+;;           stored.  Can also be a list of directories.  In that case,
+;;           when used for bulk (re)loading of snippets (at startup or
+;;           via `yas-reload-all'), directories appearing earlier in
+;;           the list override other dir's snippets.  Also, the first
+;;           directory is taken as the default for storing the user's
+;;           new snippets.
+;;
+;;           The deprecated `yas/root-directory' aliases this variable
+;;           for backward-compatibility.
+;;
+;;
+;;   Major commands are:
+;;
+;;       M-x yas-expand
+;;
+;;           Try to expand snippets before point.  In `yas-minor-mode',
+;;           this is normally bound to TAB, but you can customize it in
+;;           `yas-minor-mode-map'.
+;;
+;;       M-x yas-load-directory
+;;
+;;           Prompts you for a directory hierarchy of snippets to load.
+;;
+;;       M-x yas-activate-extra-mode
+;;
+;;           Prompts you for an extra mode to add snippets for in the
+;;           current buffer.
+;;
+;;       M-x yas-insert-snippet
+;;
+;;           Prompts you for possible snippet expansion if that is
+;;           possible according to buffer-local and snippet-local
+;;           expansion conditions.  With prefix argument, ignore these
+;;           conditions.
+;;
+;;       M-x yas-visit-snippet-file
+;;
+;;           Prompts you for possible snippet expansions like
+;;           `yas-insert-snippet', but instead of expanding it, takes
+;;           you directly to the snippet definition's file, if it
+;;           exists.
+;;
+;;       M-x yas-new-snippet
+;;
+;;           Lets you create a new snippet file in the correct
+;;           subdirectory of `yas-snippet-dirs', according to the
+;;           active major mode.
+;;
+;;       M-x yas-load-snippet-buffer
+;;
+;;           When editing a snippet, this loads the snippet.  This is
+;;           bound to "C-c C-c" while in the `snippet-mode' editing
+;;           mode.
+;;
+;;       M-x yas-tryout-snippet
+;;
+;;           When editing a snippet, this opens a new empty buffer,
+;;           sets it to the appropriate major mode and inserts the
+;;           snippet there, so you can see what it looks like.  This is
+;;           bound to "C-c C-t" while in `snippet-mode'.
+;;
+;;       M-x yas-describe-tables
+;;
+;;           Lists known snippets in a separate buffer.  User is
+;;           prompted as to whether only the currently active tables
+;;           are to be displayed, or all the tables for all major
+;;           modes.
+;;
+;;   If you have `dropdown-list' installed, you can optionally use it
+;;   as the preferred "prompting method", putting in your .emacs file,
+;;   for example:
+;;
+;;       (require 'dropdown-list)
+;;       (setq yas-prompt-functions '(yas-dropdown-prompt
+;;                                    yas-ido-prompt
+;;                                    yas-completing-prompt))
+;;
+;;   Also check out the customization group
+;;
+;;        M-x customize-group RET yasnippet RET
+;;
+;;   If you use the customization group to set variables
+;;   `yas-snippet-dirs' or `yas-global-mode', make sure the path to
+;;   "yasnippet.el" is present in the `load-path' *before* the
+;;   `custom-set-variables' is executed in your .emacs file.
+;;
+;;   For more information and detailed usage, refer to the project page:
+;;      http://github.com/joaotavora/yasnippet
+
+;;; Code:
+
+(require 'cl-lib)
+(declare-function cl-progv-after "cl-extra") ; Needed for 23.4.
+(require 'easymenu)
+(require 'help-mode)
+
+(defvar yas--editing-template)
+(defvar yas--guessed-modes)
+(defvar yas--indent-original-column)
+(defvar yas--scheduled-jit-loads)
+(defvar yas-keymap)
+(defvar yas-selected-text)
+(defvar yas-verbosity)
+(defvar yas--current-template)
+
+
+;;; User customizable variables
+
+(defgroup yasnippet nil
+  "Yet Another Snippet extension"
+  :prefix "yas-"
+  :group 'editing)
+
+(defconst yas--loaddir
+  (file-name-directory (or load-file-name buffer-file-name))
+  "Directory that yasnippet was loaded from.")
+
+(defconst yas-installed-snippets-dir (expand-file-name "snippets" yas--loaddir))
+(make-obsolete-variable 'yas-installed-snippets-dir "\
+Yasnippet no longer comes with installed snippets" "0.13")
+
+(defconst yas--default-user-snippets-dir
+  (expand-file-name "snippets" user-emacs-directory))
+
+(defcustom yas-snippet-dirs (list yas--default-user-snippets-dir)
+  "List of top-level snippet directories.
+
+Each element, a string or a symbol whose value is a string,
+designates a top-level directory where per-mode snippet
+directories can be found.
+
+Elements appearing earlier in the list override later elements'
+snippets.
+
+The first directory is taken as the default for storing snippet's
+created with `yas-new-snippet'. "
+  :type '(choice (directory :tag "Single directory")
+                 (repeat :tag "List of directories"
+                         (choice (directory) (variable))))
+  :set #'(lambda (symbol new)
+           (let ((old (and (boundp symbol)
+                           (symbol-value symbol))))
+             (set-default symbol new)
+             (unless (or (not (fboundp 'yas-reload-all))
+                         (equal old new))
+               (yas-reload-all)))))
+
+(defun yas-snippet-dirs ()
+  "Return variable `yas-snippet-dirs' as list of strings."
+  (cl-loop for e in (if (listp yas-snippet-dirs)
+                        yas-snippet-dirs
+                      (list yas-snippet-dirs))
+           collect
+           (cond ((stringp e) e)
+                 ((and (symbolp e)
+                       (boundp e)
+                       (stringp (symbol-value e)))
+                  (symbol-value e))
+                 (t
+                  (error "[yas] invalid element %s in `yas-snippet-dirs'" e)))))
+
+(defcustom yas-new-snippet-default "\
+# -*- mode: snippet -*-
+# name: $1
+# key: ${2:${1:$(yas--key-from-desc yas-text)}}
+# --
+$0`(yas-escape-text yas-selected-text)`"
+  "Default snippet to use when creating a new snippet.
+If nil, don't use any snippet."
+  :type 'string)
+
+(defcustom yas-prompt-functions '(yas-dropdown-prompt
+                                  yas-completing-prompt
+                                  yas-maybe-ido-prompt
+                                  yas-no-prompt)
+  "Functions to prompt for keys, templates, etc interactively.
+
+These functions are called with the following arguments:
+
+- PROMPT: A string to prompt the user
+
+- CHOICES: a list of strings or objects.
+
+- optional DISPLAY-FN : A function that, when applied to each of
+the objects in CHOICES will return a string.
+
+The return value of any function you put here should be one of
+the objects in CHOICES, properly formatted with DISPLAY-FN (if
+that is passed).
+
+- To signal that your particular style of prompting is
+unavailable at the moment, you can also have the function return
+nil.
+
+- To signal that the user quit the prompting process, you can
+signal `quit' with
+
+    (signal \\='quit \"user quit!\")"
+  :type '(repeat function))
+
+(defcustom yas-indent-line 'auto
+  "Controls indenting applied to a recent snippet expansion.
+
+The following values are possible:
+
+- `fixed' Indent the snippet to the current column;
+
+- `auto' Indent each line of the snippet with `indent-according-to-mode'
+
+Every other value means don't apply any snippet-side indentation
+after expansion (the manual per-line \"$>\" indentation still
+applies)."
+  :type '(choice (const :tag "Nothing"  nothing)
+                 (const :tag "Fixed"    fixed)
+                 (const :tag "Auto"     auto)))
+
+(defcustom yas-also-auto-indent-first-line nil
+  "Non-nil means also auto indent first line according to mode.
+
+Naturally this is only valid when `yas-indent-line' is `auto'."
+  :type 'boolean)
+
+(defcustom yas-also-indent-empty-lines nil
+  "Non-nil means also indent empty lines according to mode."
+  :type 'boolean)
+
+(defcustom yas-snippet-revival t
+  "Non-nil means re-activate snippet fields after undo/redo."
+  :type 'boolean)
+
+(defcustom yas-triggers-in-field nil
+  "If non-nil, allow stacked expansions (snippets inside snippets).
+
+Otherwise `yas-next-field-or-maybe-expand' just moves on to the
+next field"
+  :type 'boolean)
+
+(defcustom yas-fallback-behavior 'return-nil
+  "This option is obsolete.
+Now that the conditional keybinding `yas-maybe-expand' is
+available, there's no more need for it."
+  :type '(choice (const :tag "Call previous command"  call-other-command)
+                 (const :tag "Do nothing"             return-nil)))
+
+(make-obsolete-variable
+ 'yas-fallback-behavior
+ "For `call-other-command' behavior bind to the conditional
+command value `yas-maybe-expand', for `return-nil' behavior bind
+directly to `yas-expand'."
+ "0.12")
+
+(defcustom yas-choose-keys-first nil
+  "If non-nil, prompt for snippet key first, then for template.
+
+Otherwise prompts for all possible snippet names.
+
+This affects `yas-insert-snippet' and `yas-visit-snippet-file'."
+  :type 'boolean)
+
+(defcustom yas-choose-tables-first nil
+  "If non-nil, and multiple eligible snippet tables, prompts user for tables first.
+
+Otherwise, user chooses between the merging together of all
+eligible tables.
+
+This affects `yas-insert-snippet', `yas-visit-snippet-file'"
+  :type 'boolean)
+
+(defcustom yas-use-menu 'abbreviate
+  "Display a YASnippet menu in the menu bar.
+
+When non-nil, submenus for each snippet table will be listed
+under the menu \"Yasnippet\".
+
+- If set to `abbreviate', only the current major-mode
+menu and the modes set in `yas--extra-modes' are listed.
+
+- If set to `full', every submenu is listed
+
+- If set to nil, hide the menu.
+
+Any other non-nil value, every submenu is listed."
+  :type '(choice (const :tag "Full"  full)
+                 (const :tag "Abbreviate" abbreviate)
+                 (const :tag "No menu" nil)))
+
+(defcustom yas-trigger-symbol (or (and (eq window-system 'mac)
+                                       (ignore-errors
+                                         (char-to-string ?\x21E5))) ;; little ->| sign
+                                  " =>")
+  "The text that will be used in menu to represent the trigger."
+  :type 'string)
+
+(defcustom yas-wrap-around-region nil
+  "What to insert for snippet's $0 field.
+
+If set to a character, insert contents of corresponding register.
+If non-nil insert region contents.  This can be overridden on a
+per-snippet basis.  A value of `cua' is considered equivalent to
+`?0' for backwards compatibility."
+  :type '(choice (character :tag "Insert from register")
+                 (const t :tag "Insert region contents")
+                 (const nil :tag "Don't insert anything")
+                 (const cua))) ; backwards compat
+
+(defcustom yas-good-grace t
+  "If non-nil, don't raise errors in elisp evaluation.
+
+This affects both the inline elisp in snippets and the hook
+variables such as `yas-after-exit-snippet-hook'.
+
+If this variable's value is `inline', an error string \"[yas]
+error\" is returned instead of raising the error.  If this
+variable's value is `hooks', a message is output to according to
+`yas-verbosity-level'.  If this variable's value is t, both are
+active."
+  :type 'boolean)
+
+(defcustom yas-visit-from-menu nil
+  "If non-nil visit snippets's files from menu, instead of expanding them.
+
+This can only work when snippets are loaded from files."
+  :type 'boolean)
+
+(defcustom yas-expand-only-for-last-commands nil
+  "List of `last-command' values to restrict tab-triggering to, or nil.
+
+Leave this set at nil (the default) to be able to trigger an
+expansion simply by placing the cursor after a valid tab trigger,
+using whichever commands.
+
+Optionally, set this to something like (self-insert-command) if
+you to wish restrict expansion to only happen when the last
+letter of the snippet tab trigger was typed immediately before
+the trigger key itself."
+  :type '(repeat function))
+
+(defcustom yas-alias-to-yas/prefix-p t
+  "If non-nil make aliases for the old style yas/ prefixed symbols.
+It must be set to nil before loading yasnippet to take effect."
+  :type 'boolean
+  :group 'yasnippet)
+
+;; Only two faces, and one of them shouldn't even be used...
+;;
+(defface yas-field-highlight-face
+  '((t (:inherit 'region)))
+  "The face used to highlight the currently active field of a snippet")
+
+(defface yas--field-debug-face
+  '()
+  "The face used for debugging some overlays normally hidden")
+
+
+;;; User-visible variables
+
+(defconst yas-maybe-skip-and-clear-field
+  '(menu-item "" yas-skip-and-clear-field
+              :filter yas--maybe-clear-field-filter)
+  "A conditional key definition.
+This can be used as a key definition in keymaps to bind a key to
+`yas-skip-and-clear-field' only when at the beginning of an
+unmodified snippey field.")
+
+(defvar yas-keymap  (let ((map (make-sparse-keymap)))
+                      (define-key map [(tab)]       'yas-next-field-or-maybe-expand)
+                      (define-key map (kbd "TAB")   'yas-next-field-or-maybe-expand)
+                      (define-key map [(shift tab)] 'yas-prev-field)
+                      (define-key map [backtab]     'yas-prev-field)
+                      (define-key map (kbd "C-g")   'yas-abort-snippet)
+                      (define-key map (kbd "C-d")   yas-maybe-skip-and-clear-field)
+                      map)
+  "The active keymap while a snippet expansion is in progress.")
+
+(defvar yas-key-syntaxes (list #'yas-try-key-from-whitespace
+                               "w_.()" "w_." "w_" "w")
+  "Syntaxes and functions to help look for trigger keys before point.
+
+Each element in this list specifies how to skip buffer positions
+backwards and look for the start of a trigger key.
+
+Each element can be either a string or a function receiving the
+original point as an argument. A string element is simply passed
+to `skip-syntax-backward' whereas a function element is called
+with no arguments and should also place point before the original
+position.
+
+The string between the resulting buffer position and the original
+point is matched against the trigger keys in the active snippet
+tables.
+
+If no expandable snippets are found, the next element is the list
+is tried, unless a function element returned the symbol `again',
+in which case it is called again from the previous position and
+may once more reposition point.
+
+For example, if `yas-key-syntaxes' has the value (\"w\" \"w_\"),
+trigger keys composed exclusively of \"word\"-syntax characters
+are looked for first. Failing that, longer keys composed of
+\"word\" or \"symbol\" syntax are looked for. Therefore,
+triggering after
+
+foo-bar
+
+will, according to the \"w\" element first try \"barbaz\". If
+that isn't a trigger key, \"foo-barbaz\" is tried, respecting the
+second \"w_\" element. Notice that even if \"baz\" is a trigger
+key for an active snippet, it won't be expanded, unless a
+function is added to `yas-key-syntaxes' that eventually places
+point between \"bar\" and \"baz\".
+
+See also Info node `(elisp) Syntax Descriptors'.")
+
+(defvar yas-after-exit-snippet-hook
+  '()
+  "Hooks to run after a snippet exited.
+
+The hooks will be run in an environment where some variables bound to
+proper values:
+
+`yas-snippet-beg' : The beginning of the region of the snippet.
+
+`yas-snippet-end' : Similar to beg.
+
+Attention: These hooks are not run when exiting nested/stacked snippet expansion!")
+
+(defvar yas-before-expand-snippet-hook
+  '()
+  "Hooks to run just before expanding a snippet.")
+
+(defconst yas-not-string-or-comment-condition
+  '(if (and (let ((ppss (syntax-ppss)))
+              (or (nth 3 ppss) (nth 4 ppss)))
+            (memq this-command '(yas-expand yas-expand-from-trigger-key
+                                            yas-expand-from-keymap)))
+       '(require-snippet-condition . force-in-comment)
+     t)
+  "Disables snippet expansion in strings and comments.
+To use, set `yas-buffer-local-condition' to this value.")
+
+(defcustom yas-buffer-local-condition t
+  "Snippet expanding condition.
+
+This variable is a Lisp form which is evaluated every time a
+snippet expansion is attempted:
+
+    * If it evaluates to nil, no snippets can be expanded.
+
+    * If it evaluates to the a cons (require-snippet-condition
+      . REQUIREMENT)
+
+       * Snippets bearing no \"# condition:\" directive are not
+         considered
+
+       * Snippets bearing conditions that evaluate to nil (or
+         produce an error) won't be considered.
+
+       * If the snippet has a condition that evaluates to non-nil
+         RESULT:
+
+          * If REQUIREMENT is t, the snippet is considered
+
+          * If REQUIREMENT is `eq' RESULT, the snippet is
+            considered
+
+          * Otherwise, the snippet is not considered.
+
+    * If it evaluates to the symbol `always', all snippets are
+      considered for expansion, regardless of any conditions.
+
+    * If it evaluates to t or some other non-nil value
+
+       * Snippet bearing no conditions, or conditions that
+         evaluate to non-nil, are considered for expansion.
+
+       * Otherwise, the snippet is not considered.
+
+Here's an example preventing snippets from being expanded from
+inside comments, in `python-mode' only, with the exception of
+snippets returning the symbol `force-in-comment' in their
+conditions.
+
+ (add-hook \\='python-mode-hook
+           (lambda ()
+              (setq yas-buffer-local-condition
+                    \\='(if (python-syntax-comment-or-string-p)
+                         \\='(require-snippet-condition . force-in-comment)
+                       t))))"
+  :type
+  `(choice
+    (const :tag "Disable snippet expansion inside strings and comments"
+           ,yas-not-string-or-comment-condition)
+    (const :tag "Expand all snippets regardless of conditions" always)
+    (const :tag "Expand snippets unless their condition is nil" t)
+    (const :tag "Disable all snippet expansion" nil)
+    sexp))
+
+(defcustom yas-overlay-priority 100
+  "Priority to use for yasnippets overlays.
+This is useful to control whether snippet navigation bindings
+override bindings from other packages (e.g., `company-mode')."
+  :type 'integer)
+
+
+;;; Internal variables
+
+(defconst yas--version "0.13.0")
+
+(defvar yas--menu-table (make-hash-table)
+  "A hash table of MAJOR-MODE symbols to menu keymaps.")
+
+(defvar yas--escaped-characters
+  '(?\\ ?` ?\" ?' ?$ ?} ?{ ?\( ?\))
+  "List of characters which *might* need to be escaped.")
+
+(defconst yas--field-regexp
+  "${\\([0-9]+:\\)?\\([^}]*\\)}"
+  "A regexp to *almost* recognize a field.")
+
+(defconst yas--multi-dollar-lisp-expression-regexp
+  "$+[ \t\n]*\\(([^)]*)\\)"
+  "A regexp to *almost* recognize a \"$(...)\" expression.")
+
+(defconst yas--backquote-lisp-expression-regexp
+  "`\\([^`]*\\)`"
+  "A regexp to recognize a \"\\=`lisp-expression\\=`\" expression." )
+
+(defconst yas--transform-mirror-regexp
+  "${\\(?:\\([0-9]+\\):\\)?$\\([ \t\n]*([^}]*\\)"
+  "A regexp to *almost* recognize a mirror with a transform.")
+
+(defconst yas--simple-mirror-regexp
+  "$\\([0-9]+\\)"
+  "A regexp to recognize a simple mirror.")
+
+(defvar yas--snippet-id-seed 0
+  "Contains the next id for a snippet.")
+
+(defvar yas--original-auto-fill-function nil
+  "The original value of `auto-fill-function'.")
+(make-variable-buffer-local 'yas--original-auto-fill-function)
+
+(defvar yas--watch-auto-fill-backtrace nil)
+
+(defun yas--watch-auto-fill (sym newval op _where)
+  (when (and (or (and (eq sym 'yas--original-auto-fill-function)
+                      (null newval)
+                      (eq auto-fill-function 'yas--auto-fill))
+                 (and (eq sym 'auto-fill-function)
+                      (eq newval 'yas--auto-fill)
+                      (null yas--original-auto-fill-function)))
+             (null yas--watch-auto-fill-backtrace)
+             (fboundp 'backtrace-frames) ; Suppress compiler warning.
+             ;; If we're about to change `auto-fill-function' too,
+             ;; it's okay (probably).
+             (not (and (eq op 'makunbound)
+                       (not (eq (default-value 'auto-fill-function) 'yas--auto-fill))
+                       (cl-member 'kill-all-local-variables
+                                  (backtrace-frames 'yas--watch-auto-fill)
+                                  :key (lambda (frame) (nth 1 frame))))))
+    (setq yas--watch-auto-fill-backtrace
+          (backtrace-frames 'yas--watch-auto-fill))))
+
+;; Try to get more info on #873/919 (this only works for Emacs 26+).
+(when (fboundp 'add-variable-watcher)
+  (add-variable-watcher 'yas--original-auto-fill-function
+                        #'yas--watch-auto-fill)
+  (add-variable-watcher 'auto-fill-function
+                        #'yas--watch-auto-fill))
+
+(defun yas--snippet-next-id ()
+  (let ((id yas--snippet-id-seed))
+    (cl-incf yas--snippet-id-seed)
+    id))
+
+
+;;; Minor mode stuff
+
+(defvar yas--minor-mode-menu nil
+  "Holds the YASnippet menu.")
+
+(defvar yas--condition-cache-timestamp nil)
+
+(defun yas--maybe-expand-key-filter (cmd)
+  (when (let ((yas--condition-cache-timestamp (current-time)))
+          (yas--templates-for-key-at-point))
+    cmd))
+
+(defconst yas-maybe-expand
+  '(menu-item "" yas-expand :filter yas--maybe-expand-key-filter)
+  "A conditional key definition.
+This can be used as a key definition in keymaps to bind a key to
+`yas-expand' only when there is a snippet available to be
+expanded.")
+
+(defvar yas-minor-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map [(tab)]     yas-maybe-expand)
+    (define-key map (kbd "TAB") yas-maybe-expand)
+    (define-key map "\C-c&\C-s" 'yas-insert-snippet)
+    (define-key map "\C-c&\C-n" 'yas-new-snippet)
+    (define-key map "\C-c&\C-v" 'yas-visit-snippet-file)
+    map)
+  "The keymap used when `yas-minor-mode' is active.")
+
+(easy-menu-define yas--minor-mode-menu
+      yas-minor-mode-map
+      "Menu used when `yas-minor-mode' is active."
+  '("YASnippet" :visible yas-use-menu
+    "----"
+    ["Expand trigger" yas-expand
+     :help "Possibly expand tab trigger before point"]
+    ["Insert at point..." yas-insert-snippet
+     :help "Prompt for an expandable snippet and expand it at point"]
+    ["New snippet..." yas-new-snippet
+     :help "Create a new snippet in an appropriate directory"]
+    ["Visit snippet file..." yas-visit-snippet-file
+     :help "Prompt for an expandable snippet and find its file"]
+    "----"
+    ("Snippet menu behaviour"
+     ["Visit snippets" (setq yas-visit-from-menu t)
+      :help "Visit snippets from the menu"
+      :active t :style radio   :selected yas-visit-from-menu]
+     ["Expand snippets" (setq yas-visit-from-menu nil)
+      :help "Expand snippets from the menu"
+      :active t :style radio :selected (not yas-visit-from-menu)]
+     "----"
+     ["Show all known modes" (setq yas-use-menu 'full)
+      :help "Show one snippet submenu for each loaded table"
+      :active t :style radio   :selected (eq yas-use-menu 'full)]
+     ["Abbreviate according to current mode" (setq yas-use-menu 'abbreviate)
+      :help "Show only snippet submenus for the current active modes"
+      :active t :style radio   :selected (eq yas-use-menu 'abbreviate)])
+    ("Indenting"
+     ["Auto" (setq yas-indent-line 'auto)
+      :help "Indent each line of the snippet with `indent-according-to-mode'"
+      :active t :style radio   :selected (eq yas-indent-line 'auto)]
+     ["Fixed" (setq yas-indent-line 'fixed)
+      :help "Indent the snippet to the current column"
+      :active t :style radio   :selected (eq yas-indent-line 'fixed)]
+     ["None" (setq yas-indent-line 'none)
+      :help "Don't apply any particular snippet indentation after expansion"
+      :active t :style radio   :selected (not (member yas-indent-line '(fixed auto)))]
+     "----"
+     ["Also auto indent first line" (setq yas-also-auto-indent-first-line
+                                          (not yas-also-auto-indent-first-line))
+      :help "When auto-indenting also, auto indent the first line menu"
+      :active (eq yas-indent-line 'auto)
+      :style toggle :selected yas-also-auto-indent-first-line]
+     )
+    ("Prompting method"
+     ["System X-widget" (setq yas-prompt-functions
+                              (cons #'yas-x-prompt
+                                    (remove #'yas-x-prompt
+                                            yas-prompt-functions)))
+      :help "Use your windowing system's (gtk, mac, windows, etc...) default menu"
+      :active t :style radio   :selected (eq (car yas-prompt-functions)
+                                             #'yas-x-prompt)]
+     ["Dropdown-list" (setq yas-prompt-functions
+                            (cons #'yas-dropdown-prompt
+                                  (remove #'yas-dropdown-prompt
+                                          yas-prompt-functions)))
+      :help "Use a special dropdown list"
+      :active t :style radio   :selected (eq (car yas-prompt-functions)
+                                             #'yas-dropdown-prompt)]
+     ["Ido" (setq yas-prompt-functions
+                  (cons #'yas-ido-prompt
+                        (remove #'yas-ido-prompt
+                                yas-prompt-functions)))
+      :help "Use an ido-style minibuffer prompt"
+      :active t :style radio   :selected (eq (car yas-prompt-functions)
+                                             #'yas-ido-prompt)]
+     ["Completing read" (setq yas-prompt-functions
+                              (cons #'yas-completing-prompt
+                                    (remove #'yas-completing-prompt
+                                            yas-prompt-functions)))
+      :help "Use a normal minibuffer prompt"
+      :active t :style radio   :selected (eq (car yas-prompt-functions)
+                                             #'yas-completing-prompt)]
+     )
+    ("Misc"
+     ["Wrap region in exit marker"
+      (setq yas-wrap-around-region
+            (not yas-wrap-around-region))
+      :help "If non-nil automatically wrap the selected text in the $0 snippet exit"
+      :style toggle :selected yas-wrap-around-region]
+     ["Allow stacked expansions "
+      (setq yas-triggers-in-field
+            (not yas-triggers-in-field))
+      :help "If non-nil allow snippets to be triggered inside other snippet fields"
+      :style toggle :selected yas-triggers-in-field]
+     ["Revive snippets on undo "
+      (setq yas-snippet-revival
+            (not yas-snippet-revival))
+      :help "If non-nil allow snippets to become active again after undo"
+      :style toggle :selected yas-snippet-revival]
+     ["Good grace "
+      (setq yas-good-grace
+            (not yas-good-grace))
+      :help "If non-nil don't raise errors in bad embedded elisp in snippets"
+      :style toggle :selected yas-good-grace]
+     )
+    "----"
+    ["Load snippets..."  yas-load-directory
+     :help "Load snippets from a specific directory"]
+    ["Reload everything" yas-reload-all
+     :help "Cleanup stuff, reload snippets, rebuild menus"]
+    ["About"            yas-about
+     :help "Display some information about YASnippet"]))
+
+(defvar yas--extra-modes nil
+  "An internal list of modes for which to also lookup snippets.
+
+This variable probably makes more sense as buffer-local, so
+ensure your use `make-local-variable' when you set it.")
+(define-obsolete-variable-alias 'yas-extra-modes 'yas--extra-modes "0.9.1")
+
+(defvar yas--tables (make-hash-table)
+  "A hash table of mode symbols to `yas--table' objects.")
+
+(defvar yas--parents (make-hash-table)
+  "A hash table of mode symbols do lists of direct parent mode symbols.
+
+This list is populated when reading the \".yas-parents\" files
+found when traversing snippet directories with
+`yas-load-directory'.
+
+There might be additional parenting information stored in the
+`derived-mode-parent' property of some mode symbols, but that is
+not recorded here.")
+
+(defvar yas--direct-keymaps (list)
+  "Keymap alist supporting direct snippet keybindings.
+
+This variable is placed in `emulation-mode-map-alists'.
+
+Its elements looks like (TABLE-NAME . KEYMAP).  They're
+instantiated on `yas-reload-all' but KEYMAP is added to only when
+loading snippets.  `yas--direct-TABLE-NAME' is then a variable
+set buffer-locally when entering `yas-minor-mode'.  KEYMAP binds
+all defined direct keybindings to `yas-maybe-expand-from-keymap'
+which decides on the snippet to expand.")
+
+(defun yas-direct-keymaps-reload ()
+  "Force reload the direct keybinding for active snippet tables."
+  (interactive)
+  (setq yas--direct-keymaps nil)
+  (maphash #'(lambda (name table)
+               (push (cons (intern (format "yas--direct-%s" name))
+                           (yas--table-direct-keymap table))
+                     yas--direct-keymaps))
+           yas--tables))
+
+(defun yas--modes-to-activate (&optional mode)
+  "Compute list of mode symbols that are active for `yas-expand' and friends."
+  (defvar yas--dfs)        ;We rely on dynbind.  We could use `letrec' instead!
+  (let* ((explored (if mode (list mode) ; Building up list in reverse.
+                     (cons major-mode (reverse yas--extra-modes))))
+         (yas--dfs
+          (lambda (mode)
+            (cl-loop for neighbour
+                     in (cl-list* (get mode 'derived-mode-parent)
+                                  ;; NOTE: `fboundp' check is redundant
+                                  ;; since Emacs 24.4.
+                                  (and (fboundp mode) (symbol-function mode))
+                                  (gethash mode yas--parents))
+                     when (and neighbour
+                               (not (memq neighbour explored))
+                               (symbolp neighbour))
+                     do (push neighbour explored)
+                     (funcall yas--dfs neighbour)))))
+    (mapc yas--dfs explored)
+    (nreverse explored)))
+
+(defvar yas-minor-mode-hook nil
+  "Hook run when `yas-minor-mode' is turned on.")
+
+(defun yas--auto-fill-wrapper ()
+  (when (and auto-fill-function
+             (not (eq auto-fill-function #'yas--auto-fill)))
+    (setq yas--original-auto-fill-function auto-fill-function)
+    (setq auto-fill-function #'yas--auto-fill)))
+
+;;;###autoload
+(define-minor-mode yas-minor-mode
+  "Toggle YASnippet mode.
+
+When YASnippet mode is enabled, `yas-expand', normally bound to
+the TAB key, expands snippets of code depending on the major
+mode.
+
+With no argument, this command toggles the mode.
+positive prefix argument turns on the mode.
+Negative prefix argument turns off the mode.
+
+Key bindings:
+\\{yas-minor-mode-map}"
+  :lighter " yas" ;; The indicator for the mode line.
+  (cond ((and yas-minor-mode (featurep 'yasnippet))
+         ;; Install the direct keymaps in `emulation-mode-map-alists'
+         ;; (we use `add-hook' even though it's not technically a hook,
+         ;; but it works). Then define variables named after modes to
+         ;; index `yas--direct-keymaps'.
+         ;;
+         ;; Also install the post-command-hook.
+         ;;
+         (cl-pushnew 'yas--direct-keymaps emulation-mode-map-alists)
+         (add-hook 'post-command-hook #'yas--post-command-handler nil t)
+         ;; Set the `yas--direct-%s' vars for direct keymap expansion
+         ;;
+         (dolist (mode (yas--modes-to-activate))
+           (let ((name (intern (format "yas--direct-%s" mode))))
+             (set-default name nil)
+             (set (make-local-variable name) t)))
+         ;; Perform JIT loads
+         (yas--load-pending-jits)
+         ;; Install auto-fill handler.
+         (yas--auto-fill-wrapper)       ; Now...
+         (add-hook 'auto-fill-mode-hook #'yas--auto-fill-wrapper)) ; or later.
+        (t
+         ;; Uninstall the direct keymaps, post-command hook, and
+         ;; auto-fill handler.
+         (remove-hook 'post-command-hook #'yas--post-command-handler t)
+         (remove-hook 'auto-fill-mode-hook #'yas--auto-fill-wrapper)
+         (when (local-variable-p 'yas--original-auto-fill-function)
+           (setq auto-fill-function yas--original-auto-fill-function))
+         (setq emulation-mode-map-alists
+               (remove 'yas--direct-keymaps emulation-mode-map-alists)))))
+
+(defun yas-activate-extra-mode (mode)
+  "Activates the snippets for the given `mode' in the buffer.
+
+The function can be called in the hook of a minor mode to
+activate snippets associated with that mode."
+  (interactive
+   (let (modes
+         symbol)
+     (maphash (lambda (k _)
+                (setq modes (cons (list k) modes)))
+              yas--parents)
+     (setq symbol (completing-read
+                   "Activate mode: " modes nil t))
+     (list
+      (when (not (string= "" symbol))
+        (intern symbol)))))
+  (when mode
+    (add-to-list (make-local-variable 'yas--extra-modes) mode)
+    (yas--load-pending-jits)))
+
+(defun yas-deactivate-extra-mode (mode)
+  "Deactivates the snippets for the given `mode' in the buffer."
+  (interactive
+   (list (intern
+          (completing-read
+           "Deactivate mode: " (mapcar #'list yas--extra-modes) nil t))))
+  (set (make-local-variable 'yas--extra-modes)
+       (remove mode
+               yas--extra-modes)))
+
+(define-obsolete-variable-alias 'yas-dont-activate
+  'yas-dont-activate-functions "0.9.2")
+(defvar yas-dont-activate-functions (list #'minibufferp)
+  "Special hook to control which buffers `yas-global-mode' affects.
+Functions are called with no argument, and should return non-nil to prevent
+`yas-global-mode' from enabling yasnippet in this buffer.
+
+In Emacsen < 24, this variable is buffer-local.  Because
+`yas-minor-mode-on' is called by `yas-global-mode' after
+executing the buffer's major mode hook, setting this variable
+there is an effective way to define exceptions to the \"global\"
+activation behaviour.
+
+In Emacsen >= 24, only the global value is used.  To define
+per-mode exceptions to the \"global\" activation behaviour, call
+`yas-minor-mode' with a negative argument directily in the major
+mode's hook.")
+(unless (> emacs-major-version 23)
+  (with-no-warnings
+    (make-variable-buffer-local 'yas-dont-activate)))
+
+
+(defun yas-minor-mode-on ()
+  "Turn on YASnippet minor mode.
+
+Honour `yas-dont-activate-functions', which see."
+  (interactive)
+  (unless (or
+           ;; The old behavior used for Emacs<24 was to set
+           ;; `yas-dont-activate-functions' to t buffer-locally.
+           (not (or (listp yas-dont-activate-functions)
+                    (functionp yas-dont-activate-functions)))
+           (run-hook-with-args-until-success 'yas-dont-activate-functions))
+    (yas-minor-mode 1)))
+
+;;;###autoload
+(define-globalized-minor-mode yas-global-mode yas-minor-mode yas-minor-mode-on)
+
+(defun yas--global-mode-reload-with-jit-maybe ()
+  "Run `yas-reload-all' when `yas-global-mode' is on."
+  (when yas-global-mode (yas-reload-all)))
+
+(add-hook 'yas-global-mode-hook #'yas--global-mode-reload-with-jit-maybe)
+
+
+;;; Major mode stuff
+
+(defvar yas--font-lock-keywords
+  (append '(("^#.*$" . font-lock-comment-face))
+          (with-temp-buffer
+            (let ((prog-mode-hook nil)
+                  (emacs-lisp-mode-hook nil))
+              (ignore-errors (emacs-lisp-mode)))
+            (font-lock-set-defaults)
+            (if (eq t (car-safe font-lock-keywords))
+                ;; They're "compiled", so extract the source.
+                (cadr font-lock-keywords)
+              font-lock-keywords))
+          '(("\\$\\([0-9]+\\)"
+             (0 font-lock-keyword-face)
+             (1 font-lock-string-face t))
+            ("\\${\\([0-9]+\\):?"
+             (0 font-lock-keyword-face)
+             (1 font-lock-warning-face t))
+            ("\\(\\$(\\)" 1 font-lock-preprocessor-face)
+            ("}"
+             (0 font-lock-keyword-face)))))
+
+(defvar snippet-mode-map
+  (let ((map (make-sparse-keymap)))
+    (easy-menu-define nil
+      map
+      "Menu used when snippet-mode is active."
+      (cons "Snippet"
+            (mapcar #'(lambda (ent)
+                        (when (nth 2 ent)
+                          (define-key map (nth 2 ent) (nth 1 ent)))
+                        (vector (nth 0 ent) (nth 1 ent) t))
+                    '(("Load this snippet" yas-load-snippet-buffer "\C-c\C-l")
+                      ("Load and quit window" yas-load-snippet-buffer-and-close "\C-c\C-c")
+                      ("Try out this snippet" yas-tryout-snippet "\C-c\C-t")))))
+    map)
+  "The keymap used when `snippet-mode' is active.")
+
+
+
+;;;###autoload(autoload 'snippet-mode "yasnippet" "A mode for editing yasnippets" t nil)
+(eval-and-compile
+  (if (fboundp 'prog-mode)
+      ;; `prog-mode' is new in 24.1.
+      (define-derived-mode snippet-mode prog-mode "Snippet"
+        "A mode for editing yasnippets"
+        (setq font-lock-defaults '(yas--font-lock-keywords))
+        (set (make-local-variable 'require-final-newline) nil)
+        (set (make-local-variable 'comment-start) "#")
+        (set (make-local-variable 'comment-start-skip) "#+[\t ]*")
+        (add-hook 'after-save-hook #'yas-maybe-load-snippet-buffer nil t))
+    (define-derived-mode snippet-mode fundamental-mode "Snippet"
+      "A mode for editing yasnippets"
+      (setq font-lock-defaults '(yas--font-lock-keywords))
+      (set (make-local-variable 'require-final-newline) nil)
+      (set (make-local-variable 'comment-start) "#")
+      (set (make-local-variable 'comment-start-skip) "#+[\t ]*")
+      (add-hook 'after-save-hook #'yas-maybe-load-snippet-buffer nil t))))
+
+(defun yas-snippet-mode-buffer-p ()
+  "Return non-nil if current buffer should be in `snippet-mode'.
+Meaning it's visiting a file under one of the mode directories in
+`yas-snippet-dirs'."
+  (when buffer-file-name
+    (cl-member buffer-file-name (yas-snippet-dirs)
+               :test #'file-in-directory-p)))
+
+;; We're abusing `magic-fallback-mode-alist' here because
+;; `auto-mode-alist' doesn't support function matchers.
+(add-to-list 'magic-fallback-mode-alist
+             `(yas-snippet-mode-buffer-p . snippet-mode))
+
+
+;;; Internal structs for template management
+
+(cl-defstruct (yas--template
+               (:constructor yas--make-template)
+               ;; Handles `yas-define-snippets' format, plus the
+               ;; initial TABLE argument.
+               (:constructor
+                yas--define-snippets-2
+                (table
+                 key content
+                 &optional xname condition group
+                 expand-env load-file xkeybinding xuuid save-file
+                 &aux
+                 (name (or xname
+                           ;; A little redundant: we always get a name
+                           ;; from `yas--parse-template' except when
+                           ;; there isn't a file.
+                           (and load-file (file-name-nondirectory load-file))
+                           (and save-file (file-name-nondirectory save-file))
+                           key))
+                 (keybinding (yas--read-keybinding xkeybinding))
+                 (uuid (or xuuid name))
+                 (old (gethash uuid (yas--table-uuidhash table)))
+                 (menu-binding-pair
+                  (and old (yas--template-menu-binding-pair old)))
+                 (perm-group
+                  (and old (yas--template-perm-group old))))))
+  "A template for a snippet."
+  key
+  content
+  name
+  condition
+  expand-env
+  load-file
+  save-file
+  keybinding
+  uuid
+  menu-binding-pair
+  group      ;; as dictated by the #group: directive or .yas-make-groups
+  perm-group ;; as dictated by `yas-define-menu'
+  table
+  )
+
+(cl-defstruct (yas--table (:constructor yas--make-snippet-table (name)))
+  "A table to store snippets for a particular mode.
+
+Has the following fields:
+
+`yas--table-name'
+
+  A symbol name normally corresponding to a major mode, but can
+  also be a pseudo major-mode to be used in
+  `yas-activate-extra-mode', for example.
+
+`yas--table-hash'
+
+  A hash table (KEY . NAMEHASH), known as the \"keyhash\". KEY is
+  a string or a vector, where the former is the snippet's trigger
+  and the latter means it's a direct keybinding. NAMEHASH is yet
+  another hash of (NAME . TEMPLATE) where NAME is the snippet's
+  name and TEMPLATE is a `yas--template' object.
+
+`yas--table-direct-keymap'
+
+  A keymap for the snippets in this table that have direct
+  keybindings. This is kept in sync with the keyhash, i.e., all
+  the elements of the keyhash that are vectors appear here as
+  bindings to `yas-maybe-expand-from-keymap'.
+
+`yas--table-uuidhash'
+
+  A hash table mapping snippets uuid's to the same `yas--template'
+  objects. A snippet uuid defaults to the snippet's name."
+  name
+  (hash (make-hash-table :test 'equal))
+  (uuidhash (make-hash-table :test 'equal))
+  (parents nil)
+  (direct-keymap (make-sparse-keymap)))
+
+(defun yas--get-template-by-uuid (mode uuid)
+  "Find the snippet template in MODE by its UUID."
+  (let* ((table (gethash mode yas--tables mode)))
+    (when table
+      (gethash uuid (yas--table-uuidhash table)))))
+
+;; Apropos storing/updating in TABLE, this works in two steps:
+;;
+;; 1. `yas--remove-template-by-uuid' removes any
+;;    keyhash-namehash-template mappings from TABLE, grabbing the
+;;    snippet by its uuid. Also removes mappings from TABLE's
+;;    `yas--table-direct-keymap' (FIXME: and should probably take care
+;;    of potentially stale menu bindings right?.)
+;;
+;; 2. `yas--add-template' adds this all over again.
+;;
+;;    Create a new or add to an existing keyhash-namehash mapping.
+;;
+;;  For reference on understanding this, consider three snippet
+;;  definitions:
+;;
+;;  A:   # name: The Foo
+;;       # key: foo
+;;       # binding: C-c M-l
+;;
+;;  B:   # name: Mrs Foo
+;;       # key: foo
+;;
+;;  C:   # name: The Bar
+;;       # binding: C-c M-l
+;;
+;;  D:   # name: Baz
+;;       # key: baz
+;;
+;;  keyhash       namehashes(3)      yas--template structs(4)
+;;  -----------------------------------------------------
+;;                                            __________
+;;                                           /          \
+;;  "foo"      --->  "The Foo" --->  [yas--template A]   |
+;;                   "Mrs Foo" --->  [yas--template B]   |
+;;                                                      |
+;;  [C-c M-l]  --->  "The Foo" -------------------------/
+;;                   "The Bar" --->  [yas--template C]
+;;
+;;  "baz"      --->  "Baz"     --->  [yas--template D]
+;;
+;; Additionally, since uuid defaults to the name, we have a
+;; `yas--table-uuidhash' for TABLE
+;;
+;; uuidhash       yas--template structs
+;; -------------------------------
+;; "The Foo" ---> [yas--template A]
+;; "Mrs Foo" ---> [yas--template B]
+;; "The Bar" ---> [yas--template C]
+;; "Baz"     ---> [yas--template D]
+;;
+;; FIXME: the more I look at this data-structure the more I think I'm
+;; stupid. There has to be an easier way (but beware lots of code
+;; depends on this).
+;;
+(defun yas--remove-template-by-uuid (table uuid)
+  "Remove from TABLE a template identified by UUID."
+  (let ((template (gethash uuid (yas--table-uuidhash table))))
+    (when template
+      (let* ((name                (yas--template-name template))
+             (empty-keys          nil))
+        ;; Remove the name from each of the targeted namehashes
+        ;;
+        (maphash #'(lambda (k v)
+                     (let ((template (gethash name v)))
+                       (when (and template
+                                  (equal uuid (yas--template-uuid template)))
+                         (remhash name v)
+                         (when (zerop (hash-table-count v))
+                           (push k empty-keys)))))
+                 (yas--table-hash table))
+        ;; Remove the namehash themselves if they've become empty
+        ;;
+        (dolist (key empty-keys)
+          (when (vectorp key)
+            (define-key (yas--table-direct-keymap table) key nil))
+          (remhash key (yas--table-hash table)))
+
+        ;; Finally, remove the uuid from the uuidhash
+        ;;
+        (remhash uuid (yas--table-uuidhash table))))))
+
+(defconst yas-maybe-expand-from-keymap
+  '(menu-item "" yas-expand-from-keymap
+              :filter yas--maybe-expand-from-keymap-filter))
+
+(defun yas--add-template (table template)
+  "Store in TABLE the snippet template TEMPLATE.
+
+KEY can be a string (trigger key) of a vector (direct
+keybinding)."
+  (let ((name (yas--template-name template))
+        (key (yas--template-key template))
+        (keybinding (yas--template-keybinding template))
+        (_menu-binding-pair (yas--template-menu-binding-pair-get-create template)))
+    (dolist (k (remove nil (list key keybinding)))
+      (puthash name
+               template
+               (or (gethash k
+                            (yas--table-hash table))
+                   (puthash k
+                            (make-hash-table :test 'equal)
+                            (yas--table-hash table))))
+      (when (vectorp k)
+        (define-key (yas--table-direct-keymap table) k yas-maybe-expand-from-keymap)))
+
+    ;; Update TABLE's `yas--table-uuidhash'
+    (puthash (yas--template-uuid template)
+             template
+             (yas--table-uuidhash table))))
+
+(defun yas--update-template (table template)
+  "Add or update TEMPLATE in TABLE.
+
+Also takes care of adding and updating to the associated menu.
+Return TEMPLATE."
+  ;; Remove from table by uuid
+  ;;
+  (yas--remove-template-by-uuid table (yas--template-uuid template))
+  ;; Add to table again
+  ;;
+  (yas--add-template table template)
+  ;; Take care of the menu
+  ;;
+  (yas--update-template-menu table template)
+  template)
+
+(defun yas--update-template-menu (table template)
+  "Update every menu-related for TEMPLATE."
+  (let ((menu-binding-pair (yas--template-menu-binding-pair-get-create template))
+        (key (yas--template-key template))
+        (keybinding (yas--template-keybinding template)))
+    ;; The snippet might have changed name or keys, so update
+    ;; user-visible strings
+    ;;
+    (unless (eq (cdr menu-binding-pair) :none)
+      ;; the menu item name
+      ;;
+      (setf (cl-cadar menu-binding-pair) (yas--template-name template))
+      ;; the :keys information (also visible to the user)
+      (setf (cl-getf (cdr (car menu-binding-pair)) :keys)
+            (or (and keybinding (key-description keybinding))
+                (and key (concat key yas-trigger-symbol))))))
+  (unless (yas--template-menu-managed-by-yas-define-menu template)
+    (let ((menu-keymap
+           (yas--menu-keymap-get-create (yas--table-mode table)
+                                        (mapcar #'yas--table-mode
+                                                (yas--table-parents table))))
+          (group (yas--template-group template)))
+      ;; Remove from menu keymap
+      ;;
+      (cl-assert menu-keymap)
+      (yas--delete-from-keymap menu-keymap (yas--template-uuid template))
+
+      ;; Add necessary subgroups as necessary.
+      ;;
+      (dolist (subgroup group)
+        (let ((subgroup-keymap (lookup-key menu-keymap (vector (make-symbol subgroup)))))
+          (unless (and subgroup-keymap
+                       (keymapp subgroup-keymap))
+            (setq subgroup-keymap (make-sparse-keymap))
+            (define-key menu-keymap (vector (make-symbol subgroup))
+              `(menu-item ,subgroup ,subgroup-keymap)))
+          (setq menu-keymap subgroup-keymap)))
+
+      ;; Add this entry to the keymap
+      ;;
+      (define-key menu-keymap
+        (vector (make-symbol (yas--template-uuid template)))
+        (car (yas--template-menu-binding-pair template))))))
+
+(defun yas--namehash-templates-alist (namehash)
+  "Return NAMEHASH as an alist."
+  (let (alist)
+    (maphash #'(lambda (k v)
+                 (push (cons k v) alist))
+             namehash)
+    alist))
+
+(defun yas--fetch (table key)
+  "Fetch templates in TABLE by KEY.
+
+Return a list of cons (NAME . TEMPLATE) where NAME is a
+string and TEMPLATE is a `yas--template' structure."
+  (let* ((keyhash (yas--table-hash table))
+         (namehash (and keyhash (gethash key keyhash))))
+    (when namehash
+      (yas--filter-templates-by-condition (yas--namehash-templates-alist namehash)))))
+
+
+;;; Filtering/condition logic
+
+(defun yas--eval-condition (condition)
+  (condition-case err
+      (save-excursion
+        (save-restriction
+          (save-match-data
+            (eval condition))))
+    (error (progn
+             (yas--message 1 "Error in condition evaluation: %s" (error-message-string err))
+             nil))))
+
+
+(defun yas--filter-templates-by-condition (templates)
+  "Filter the templates using the applicable condition.
+
+TEMPLATES is a list of cons (NAME . TEMPLATE) where NAME is a
+string and TEMPLATE is a `yas--template' structure.
+
+This function implements the rules described in
+`yas-buffer-local-condition'.  See that variables documentation."
+  (let ((requirement (yas--require-template-specific-condition-p)))
+    (if (eq requirement 'always)
+        templates
+      (cl-remove-if-not (lambda (pair)
+                          (yas--template-can-expand-p
+                           (yas--template-condition (cdr pair)) requirement))
+                        templates))))
+
+(defun yas--require-template-specific-condition-p ()
+  "Decide if this buffer requests/requires snippet-specific
+conditions to filter out potential expansions."
+  (if (eq 'always yas-buffer-local-condition)
+      'always
+    (let ((local-condition (or (and (consp yas-buffer-local-condition)
+                                    (yas--eval-condition yas-buffer-local-condition))
+                               yas-buffer-local-condition)))
+      (when local-condition
+        (if (eq local-condition t)
+            t
+          (and (consp local-condition)
+               (eq 'require-snippet-condition (car local-condition))
+               (symbolp (cdr local-condition))
+               (cdr local-condition)))))))
+
+(defun yas--template-can-expand-p (condition requirement)
+  "Evaluate CONDITION and REQUIREMENT and return a boolean."
+  (let* ((result (or (null condition)
+                     (yas--eval-condition condition))))
+    (cond ((eq requirement t)
+           result)
+          (t
+           (eq requirement result)))))
+
+(defun yas--table-templates (table)
+  (when table
+    (let ((acc (list)))
+      (maphash #'(lambda (_key namehash)
+                   (maphash #'(lambda (name template)
+                                (push (cons name template) acc))
+                            namehash))
+               (yas--table-hash table))
+      (yas--filter-templates-by-condition acc))))
+
+(defun yas--templates-for-key-at-point ()
+  "Find `yas--template' objects for any trigger keys preceding point.
+Returns (TEMPLATES START END). This function respects
+`yas-key-syntaxes', which see."
+  (save-excursion
+    (let ((original (point))
+          (methods yas-key-syntaxes)
+          (templates)
+          (method))
+      (while (and methods
+                  (not templates))
+        (unless (eq method (car methods))
+          ;; TRICKY: `eq'-ness test means we can only be here if
+          ;; `method' is a function that returned `again', and hence
+          ;; don't revert back to original position as per
+          ;; `yas-key-syntaxes'.
+          (goto-char original))
+        (setq method (car methods))
+        (cond ((stringp method)
+               (skip-syntax-backward method)
+               (setq methods (cdr methods)))
+              ((functionp method)
+               (unless (eq (funcall method original)
+                           'again)
+                 (setq methods (cdr methods))))
+              (t
+               (setq methods (cdr methods))
+               (yas--warning "Invalid element `%s' in `yas-key-syntaxes'" method)))
+        (let ((possible-key (buffer-substring-no-properties (point) original)))
+          (save-excursion
+            (goto-char original)
+            (setq templates
+                  (cl-mapcan (lambda (table)
+                               (yas--fetch table possible-key))
+                             (yas--get-snippet-tables))))))
+      (when templates
+        (list templates (point) original)))))
+
+(defun yas--table-all-keys (table)
+  "Get trigger keys of all active snippets in TABLE."
+  (let ((acc))
+    (maphash #'(lambda (key namehash)
+                 (when (yas--filter-templates-by-condition (yas--namehash-templates-alist namehash))
+                   (push key acc)))
+             (yas--table-hash table))
+    acc))
+
+(defun yas--table-mode (table)
+  (intern (yas--table-name table)))
+
+
+;;; Internal functions and macros:
+
+(defun yas--remove-misc-free-from-undo (old-undo-list)
+  "Tries to work around Emacs Bug#30931.
+Helper function for `yas--save-restriction-and-widen'."
+  ;; If Bug#30931 is unfixed, we get (#<Lisp_Misc_Free> . INTEGER)
+  ;; entries in the undo list.  If we call `type-of' on the
+  ;; Lisp_Misc_Free object then Emacs aborts, so try to find it by
+  ;; checking that its type is none of the expected ones.
+  (when (consp buffer-undo-list)
+    (let* ((prev buffer-undo-list)
+           (undo-list prev))
+      (while (and (consp undo-list)
+                  ;; Only check new entries.
+                  (not (eq undo-list old-undo-list)))
+        (let ((entry (pop undo-list)))
+          (when (consp entry)
+            (let ((head (car entry)))
+              (unless (or (stringp head)
+                          (markerp head)
+                          (integerp head)
+                          (symbolp head)
+                          (not (integerp (cdr entry))))
+                ;; (message "removing misc free %S" entry)
+                (setcdr prev undo-list)))))
+        (setq prev undo-list)))))
+
+(defmacro yas--save-restriction-and-widen (&rest body)
+  "Equivalent to (save-restriction (widen) BODY).
+Also tries to work around Emacs Bug#30931."
+  (declare (debug (body)) (indent 0))
+  ;; Disable garbage collection, since it could cause an abort.
+  `(let ((gc-cons-threshold most-positive-fixnum)
+         (old-undo-list buffer-undo-list))
+     (prog1 (save-restriction
+              (widen)
+              ,@body)
+       (yas--remove-misc-free-from-undo old-undo-list))))
+
+(defun yas--eval-for-string (form)
+  "Evaluate FORM and convert the result to string."
+  (let ((debug-on-error (and (not (memq yas-good-grace '(t inline)))
+                             debug-on-error)))
+    (condition-case oops
+        (save-excursion
+          (yas--save-restriction-and-widen
+            (save-match-data
+              (let ((result (eval form)))
+                (when result
+                  (format "%s" result))))))
+      ((debug error) (cdr oops)))))
+
+(defun yas--eval-for-effect (form)
+  (yas--safely-call-fun (apply-partially #'eval form)))
+
+(defun yas--read-lisp (string &optional nil-on-error)
+  "Read STRING as a elisp expression and return it.
+
+In case STRING in an invalid expression and NIL-ON-ERROR is nil,
+return an expression that when evaluated will issue an error."
+  (condition-case err
+      (read string)
+    (error (and (not nil-on-error)
+                `(error (error-message-string ,err))))))
+
+(defun yas--read-keybinding (keybinding)
+  "Read KEYBINDING as a snippet keybinding, return a vector."
+  (when (and keybinding
+             (not (string-match "keybinding" keybinding)))
+    (condition-case err
+        (let ((res (or (and (string-match "^\\[.*\\]$" keybinding)
+                            (read keybinding))
+                       (read-kbd-macro keybinding 'need-vector))))
+          res)
+      (error
+       (yas--message 2 "warning: keybinding \"%s\" invalid since %s."
+                keybinding (error-message-string err))
+       nil))))
+
+(defun yas--table-get-create (mode)
+  "Get or create the snippet table corresponding to MODE."
+  (let ((table (gethash mode
+                        yas--tables)))
+    (unless table
+      (setq table (yas--make-snippet-table (symbol-name mode)))
+      (puthash mode table yas--tables)
+      (push (cons (intern (format "yas--direct-%s" mode))
+                  (yas--table-direct-keymap table))
+            yas--direct-keymaps))
+    table))
+
+(defun yas--get-snippet-tables (&optional mode)
+  "Get snippet tables for MODE.
+
+MODE defaults to the current buffer's `major-mode'.
+
+Return a list of `yas--table' objects.  The list of modes to
+consider is returned by `yas--modes-to-activate'"
+  (remove nil
+          (mapcar #'(lambda (name)
+                      (gethash name yas--tables))
+                  (yas--modes-to-activate mode))))
+
+(defun yas--menu-keymap-get-create (mode &optional parents)
+  "Get or create the menu keymap for MODE and its PARENTS.
+
+This may very well create a plethora of menu keymaps and arrange
+them all in `yas--menu-table'"
+  (let* ((menu-keymap (or (gethash mode yas--menu-table)
+                          (puthash mode (make-sparse-keymap) yas--menu-table))))
+    (mapc #'yas--menu-keymap-get-create parents)
+    (define-key yas--minor-mode-menu (vector mode)
+        `(menu-item ,(symbol-name mode) ,menu-keymap
+                    :visible (yas--show-menu-p ',mode)))
+    menu-keymap))
+
+
+;;; Template-related and snippet loading functions
+
+(defun yas--parse-template (&optional file)
+  "Parse the template in the current buffer.
+
+Optional FILE is the absolute file name of the file being
+parsed.
+
+Optional GROUP is the group where the template is to go,
+otherwise we attempt to calculate it from FILE.
+
+Return a snippet-definition, i.e. a list
+
+ (KEY TEMPLATE NAME CONDITION GROUP VARS LOAD-FILE KEYBINDING UUID)
+
+If the buffer contains a line of \"# --\" then the contents above
+this line are ignored. Directives can set most of these with the syntax:
+
+# directive-name : directive-value
+
+Here's a list of currently recognized directives:
+
+ * type
+ * name
+ * contributor
+ * condition
+ * group
+ * key
+ * expand-env
+ * binding
+ * uuid"
+  (goto-char (point-min))
+  (let* ((type 'snippet)
+         (name (and file
+                    (file-name-nondirectory file)))
+         (key nil)
+         template
+         bound
+         condition
+         (group (and file
+                     (yas--calculate-group file)))
+         expand-env
+         binding
+         uuid)
+    (if (re-search-forward "^# --\\s-*\n" nil t)
+        (progn (setq template
+                     (buffer-substring-no-properties (point)
+                                                     (point-max)))
+               (setq bound (point))
+               (goto-char (point-min))
+               (while (re-search-forward "^# *\\([^ ]+?\\) *: *\\(.*?\\)[[:space:]]*$" bound t)
+                 (when (string= "uuid" (match-string-no-properties 1))
+                   (setq uuid (match-string-no-properties 2)))
+                 (when (string= "type" (match-string-no-properties 1))
+                   (setq type (if (string= "command" (match-string-no-properties 2))
+                                  'command
+                                'snippet)))
+                 (when (string= "key" (match-string-no-properties 1))
+                   (setq key (match-string-no-properties 2)))
+                 (when (string= "name" (match-string-no-properties 1))
+                   (setq name (match-string-no-properties 2)))
+                 (when (string= "condition" (match-string-no-properties 1))
+                   (setq condition (yas--read-lisp (match-string-no-properties 2))))
+                 (when (string= "group" (match-string-no-properties 1))
+                   (setq group (match-string-no-properties 2)))
+                 (when (string= "expand-env" (match-string-no-properties 1))
+                   (setq expand-env (yas--read-lisp (match-string-no-properties 2)
+                                                   'nil-on-error)))
+                 (when (string= "binding" (match-string-no-properties 1))
+                   (setq binding (match-string-no-properties 2)))))
+      (setq template
+            (buffer-substring-no-properties (point-min) (point-max))))
+    (unless (or key binding)
+      (setq key (and file (file-name-nondirectory file))))
+    (when (eq type 'command)
+      (setq template (yas--read-lisp (concat "(progn" template ")"))))
+    (when group
+      (setq group (split-string group "\\.")))
+    (list key template name condition group expand-env file binding uuid)))
+
+(defun yas--calculate-group (file)
+  "Calculate the group for snippet file path FILE."
+  (let* ((dominating-dir (locate-dominating-file file
+                                                 ".yas-make-groups"))
+         (extra-path (and dominating-dir
+                          (file-relative-name file dominating-dir)))
+         (extra-dir (and extra-path
+                         (file-name-directory extra-path)))
+         (group (and extra-dir
+                     (replace-regexp-in-string "/"
+                                               "."
+                                               (directory-file-name extra-dir)))))
+    group))
+
+(defun yas--subdirs (directory &optional filep)
+  "Return subdirs or files of DIRECTORY according to FILEP."
+  (cl-remove-if (lambda (file)
+                  (or (string-match "\\`\\."
+                                    (file-name-nondirectory file))
+                      (string-match "\\`#.*#\\'"
+                                    (file-name-nondirectory file))
+                      (string-match "~\\'"
+                                    (file-name-nondirectory file))
+                      (if filep
+                          (file-directory-p file)
+                        (not (file-directory-p file)))))
+                (directory-files directory t)))
+
+(defun yas--make-menu-binding (template)
+  (let ((mode (yas--table-mode (yas--template-table template))))
+    `(lambda () (interactive) (yas--expand-or-visit-from-menu ',mode ,(yas--template-uuid template)))))
+
+(defun yas--expand-or-visit-from-menu (mode uuid)
+  (let* ((table (yas--table-get-create mode))
+         (yas--current-template (and table
+                                    (gethash uuid (yas--table-uuidhash table)))))
+    (when yas--current-template
+      (if yas-visit-from-menu
+          (yas--visit-snippet-file-1 yas--current-template)
+        (let ((where (if (region-active-p)
+                         (cons (region-beginning) (region-end))
+                       (cons (point) (point)))))
+          (yas-expand-snippet (yas--template-content yas--current-template)
+                              (car where)
+                              (cdr where)
+                              (yas--template-expand-env yas--current-template)))))))
+
+(defun yas--key-from-desc (text)
+  "Return a yasnippet key from a description string TEXT."
+  (replace-regexp-in-string "\\(\\w+\\).*" "\\1" text))
+
+
+;;; Popping up for keys and templates
+
+(defun yas--prompt-for-template (templates &optional prompt)
+  "Interactively choose a template from the list TEMPLATES.
+
+TEMPLATES is a list of `yas--template'.
+
+Optional PROMPT sets the prompt to use."
+  (when templates
+    (setq templates
+          (sort templates #'(lambda (t1 t2)
+                              (< (length (yas--template-name t1))
+                                 (length (yas--template-name t2))))))
+    (cl-some (lambda (fn)
+               (funcall fn (or prompt "Choose a snippet: ")
+                        templates
+                        #'yas--template-name))
+             yas-prompt-functions)))
+
+(defun yas--prompt-for-keys (keys &optional prompt)
+  "Interactively choose a template key from the list KEYS.
+
+Optional PROMPT sets the prompt to use."
+  (when keys
+    (cl-some (lambda (fn)
+               (funcall fn (or prompt "Choose a snippet key: ") keys))
+             yas-prompt-functions)))
+
+(defun yas--prompt-for-table (tables &optional prompt)
+  "Interactively choose a table from the list TABLES.
+
+Optional PROMPT sets the prompt to use."
+  (when tables
+    (cl-some (lambda (fn)
+               (funcall fn (or prompt "Choose a snippet table: ")
+                        tables
+                        #'yas--table-name))
+             yas-prompt-functions)))
+
+(defun yas-x-prompt (prompt choices &optional display-fn)
+  "Display choices in a x-window prompt."
+  (when (and window-system choices)
+    ;; Let window position be recalculated to ensure that
+    ;; `posn-at-point' returns non-nil.
+    (redisplay)
+    (or
+     (x-popup-menu
+      (if (fboundp 'posn-at-point)
+          (let ((x-y (posn-x-y (posn-at-point (point)))))
+            (list (list (+ (car x-y) 10)
+                        (+ (cdr x-y) 20))
+                  (selected-window)))
+        t)
+      `(,prompt ("title"
+                 ,@(cl-mapcar (lambda (c d) `(,(concat "   " d) . ,c))
+                              choices
+                              (if display-fn (mapcar display-fn choices)
+                                choices)))))
+     (keyboard-quit))))
+
+(defun yas-maybe-ido-prompt (prompt choices &optional display-fn)
+  (when (bound-and-true-p ido-mode)
+    (yas-ido-prompt prompt choices display-fn)))
+
+(defun yas-ido-prompt (prompt choices &optional display-fn)
+  (require 'ido)
+  (yas-completing-prompt prompt choices display-fn #'ido-completing-read))
+
+(defun yas-dropdown-prompt (_prompt choices &optional display-fn)
+  (when (fboundp 'dropdown-list)
+    (let* ((formatted-choices
+            (if display-fn (mapcar display-fn choices) choices))
+           (n (dropdown-list formatted-choices)))
+      (if n (nth n choices)
+        (keyboard-quit)))))
+
+(defun yas-completing-prompt (prompt choices &optional display-fn completion-fn)
+  (let* ((formatted-choices
+          (if display-fn (mapcar display-fn choices) choices))
+         (chosen (funcall (or completion-fn #'completing-read)
+                          prompt formatted-choices
+                          nil 'require-match nil nil)))
+    (if (eq choices formatted-choices)
+        chosen
+      (nth (or (cl-position chosen formatted-choices :test #'string=) 0)
+           choices))))
+
+(defun yas-no-prompt (_prompt choices &optional _display-fn)
+  (cl-first choices))
+
+
+;;; Defining snippets
+;; This consists of creating and registering `yas--template' objects in the
+;; correct tables.
+;;
+
+(defvar yas--creating-compiled-snippets nil)
+
+(defun yas--define-snippets-1 (snippet snippet-table)
+  "Helper for `yas-define-snippets'."
+  ;; Update the appropriate table.  Also takes care of adding the
+  ;; key indicators in the templates menu entry, if any.
+  (yas--update-template
+   snippet-table (apply #'yas--define-snippets-2 snippet-table snippet)))
+
+(defun yas-define-snippets (mode snippets)
+  "Define SNIPPETS for MODE.
+
+SNIPPETS is a list of snippet definitions, each taking the
+following form
+
+ (KEY TEMPLATE NAME CONDITION GROUP EXPAND-ENV LOAD-FILE KEYBINDING UUID SAVE-FILE)
+
+Within these, only KEY and TEMPLATE are actually mandatory.
+
+TEMPLATE might be a Lisp form or a string, depending on whether
+this is a snippet or a snippet-command.
+
+CONDITION, EXPAND-ENV and KEYBINDING are Lisp forms, they have
+been `yas--read-lisp'-ed and will eventually be
+`yas--eval-for-string'-ed.
+
+The remaining elements are strings.
+
+FILE is probably of very little use if you're programatically
+defining snippets.
+
+UUID is the snippet's \"unique-id\". Loading a second snippet
+file with the same uuid would replace the previous snippet.
+
+You can use `yas--parse-template' to return such lists based on
+the current buffers contents."
+  (if yas--creating-compiled-snippets
+      (let ((print-length nil))
+        (insert ";;; Snippet definitions:\n;;;\n")
+        (dolist (snippet snippets)
+          ;; Fill in missing elements with nil.
+          (setq snippet (append snippet (make-list (- 10 (length snippet)) nil)))
+          ;; Move LOAD-FILE to SAVE-FILE because we will load from the
+          ;; compiled file, not LOAD-FILE.
+          (let ((load-file (nth 6 snippet)))
+            (setcar (nthcdr 6 snippet) nil)
+            (setcar (nthcdr 9 snippet) load-file)))
+        (insert (pp-to-string
+                 `(yas-define-snippets ',mode ',snippets)))
+        (insert "\n\n"))
+    ;; Normal case.
+    (let ((snippet-table (yas--table-get-create mode))
+          (template nil))
+      (dolist (snippet snippets)
+        (setq template (yas--define-snippets-1 snippet
+                                               snippet-table)))
+      template)))
+
+
+;;; Loading snippets from files
+
+(defun yas--template-get-file (template)
+  "Return TEMPLATE's LOAD-FILE or SAVE-FILE."
+  (or (yas--template-load-file template)
+      (let ((file (yas--template-save-file template)))
+        (when file
+          (yas--message 3 "%s has no load file, using save file, %s, instead."
+                        (yas--template-name template) file))
+        file)))
+
+(defun yas--load-yas-setup-file (file)
+  (if (not yas--creating-compiled-snippets)
+      ;; Normal case.
+      (load file 'noerror (<= yas-verbosity 4))
+    (let ((elfile (concat file ".el")))
+      (when (file-exists-p elfile)
+        (insert ";;; contents of the .yas-setup.el support file:\n;;;\n")
+        (insert-file-contents elfile)
+        (goto-char (point-max))))))
+
+(defun yas--define-parents (mode parents)
+  "Add PARENTS to the list of MODE's parents."
+  (puthash mode (cl-remove-duplicates
+                 (append parents
+                         (gethash mode yas--parents)))
+           yas--parents))
+
+(defun yas-load-directory (top-level-dir &optional use-jit interactive)
+  "Load snippets in directory hierarchy TOP-LEVEL-DIR.
+
+Below TOP-LEVEL-DIR each directory should be a mode name.
+
+With prefix argument USE-JIT do jit-loading of snippets."
+  (interactive
+   (list (read-directory-name "Select the root directory: " nil nil t)
+         current-prefix-arg t))
+  (unless yas-snippet-dirs
+    (setq yas-snippet-dirs top-level-dir))
+  (let ((impatient-buffers))
+    (dolist (dir (yas--subdirs top-level-dir))
+      (let* ((major-mode-and-parents (yas--compute-major-mode-and-parents
+                                      (concat dir "/dummy")))
+             (mode-sym (car major-mode-and-parents))
+             (parents (cdr major-mode-and-parents)))
+        ;; Attention: The parents and the menus are already defined
+        ;; here, even if the snippets are later jit-loaded.
+        ;;
+        ;; * We need to know the parents at this point since entering a
+        ;;   given mode should jit load for its parents
+        ;;   immediately. This could be reviewed, the parents could be
+        ;;   discovered just-in-time-as well
+        ;;
+        ;; * We need to create the menus here to support the `full'
+        ;;   option to `yas-use-menu' (all known snippet menus are shown to the user)
+        ;;
+        (yas--define-parents mode-sym parents)
+        (yas--menu-keymap-get-create mode-sym)
+        (let ((fun (apply-partially #'yas--load-directory-1 dir mode-sym)))
+          (if use-jit
+              (yas--schedule-jit mode-sym fun)
+            (funcall fun)))
+        ;; Look for buffers that are already in `mode-sym', and so
+        ;; need the new snippets immediately...
+        ;;
+        (when use-jit
+          (cl-loop for buffer in (buffer-list)
+                   do (with-current-buffer buffer
+                        (when (eq major-mode mode-sym)
+                          (yas--message 4 "Discovered there was already %s in %s" buffer mode-sym)
+                          (push buffer impatient-buffers)))))))
+    ;; ...after TOP-LEVEL-DIR has been completely loaded, call
+    ;; `yas--load-pending-jits' in these impatient buffers.
+    ;;
+    (cl-loop for buffer in impatient-buffers
+             do (with-current-buffer buffer (yas--load-pending-jits))))
+  (when interactive
+    (yas--message 3 "Loaded snippets from %s." top-level-dir)))
+
+(defun yas--load-directory-1 (directory mode-sym)
+  "Recursively load snippet templates from DIRECTORY."
+  (if yas--creating-compiled-snippets
+      (let ((output-file (expand-file-name ".yas-compiled-snippets.el"
+                                           directory)))
+        (with-temp-file output-file
+          (insert (format ";;; Compiled snippets and support files for `%s'\n"
+                          mode-sym))
+          (yas--load-directory-2 directory mode-sym)
+          (insert (format ";;; Do not edit! File generated at %s\n"
+                          (current-time-string)))))
+    ;; Normal case.
+    (unless (file-exists-p (expand-file-name ".yas-skip" directory))
+      (unless (and (load (expand-file-name ".yas-compiled-snippets" directory) 'noerror (<= yas-verbosity 3))
+                   (progn (yas--message 4 "Loaded compiled snippets from %s" directory) t))
+        (yas--message 4 "Loading snippet files from %s" directory)
+        (yas--load-directory-2 directory mode-sym)))))
+
+(defun yas--load-directory-2 (directory mode-sym)
+  ;; Load .yas-setup.el files wherever we find them
+  ;;
+  (yas--load-yas-setup-file (expand-file-name ".yas-setup" directory))
+  (let* ((default-directory directory)
+         (snippet-defs nil))
+    ;; load the snippet files
+    ;;
+    (with-temp-buffer
+      (dolist (file (yas--subdirs directory 'no-subdirs-just-files))
+        (when (file-readable-p file)
+          ;; Erase the buffer instead of passing non-nil REPLACE to
+          ;; `insert-file-contents' (avoids Emacs bug #23659).
+          (erase-buffer)
+          (insert-file-contents file)
+          (push (yas--parse-template file)
+                snippet-defs))))
+    (when snippet-defs
+      (yas-define-snippets mode-sym
+                           snippet-defs))
+    ;; now recurse to a lower level
+    ;;
+    (dolist (subdir (yas--subdirs directory))
+      (yas--load-directory-2 subdir
+                            mode-sym))))
+
+(defun yas--load-snippet-dirs (&optional nojit)
+  "Reload the directories listed in `yas-snippet-dirs' or
+prompt the user to select one."
+  (let (errors)
+    (if (null yas-snippet-dirs)
+        (call-interactively 'yas-load-directory)
+      (when (member yas--default-user-snippets-dir yas-snippet-dirs)
+        (make-directory yas--default-user-snippets-dir t))
+      (dolist (directory (reverse (yas-snippet-dirs)))
+        (cond ((file-directory-p directory)
+               (yas-load-directory directory (not nojit))
+               (if nojit
+                   (yas--message 4 "Loaded %s" directory)
+                 (yas--message 4 "Prepared just-in-time loading for %s" directory)))
+              (t
+               (push (yas--message 1 "Check your `yas-snippet-dirs': %s is not a directory" directory) errors)))))
+    errors))
+
+(defun yas-reload-all (&optional no-jit interactive)
+  "Reload all snippets and rebuild the YASnippet menu.
+
+When NO-JIT is non-nil force immediate reload of all known
+snippets under `yas-snippet-dirs', otherwise use just-in-time
+loading.
+
+When called interactively, use just-in-time loading when given a
+prefix argument."
+  (interactive (list (not current-prefix-arg) t))
+  (catch 'abort
+    (let ((errors)
+          (snippet-editing-buffers
+           (cl-remove-if-not (lambda (buffer)
+                               (with-current-buffer buffer
+                                 yas--editing-template))
+                             (buffer-list))))
+      ;; Warn if there are buffers visiting snippets, since reloading will break
+      ;; any on-line editing of those buffers.
+      ;;
+      (when snippet-editing-buffers
+          (if interactive
+              (if (y-or-n-p "Some buffers editing live snippets, close them and proceed with reload? ")
+                  (mapc #'kill-buffer snippet-editing-buffers)
+                (yas--message 1 "Aborted reload...")
+                (throw 'abort nil))
+            ;; in a non-interactive use, at least set
+            ;; `yas--editing-template' to nil, make it guess it next time around
+            (mapc #'(lambda (buffer)
+                      (with-current-buffer buffer
+                        (kill-local-variable 'yas--editing-template)))
+                  (buffer-list))))
+
+      ;; Empty all snippet tables and parenting info
+      ;;
+      (setq yas--tables (make-hash-table))
+      (setq yas--parents (make-hash-table))
+
+      ;; Before killing `yas--menu-table' use its keys to cleanup the
+      ;; mode menu parts of `yas--minor-mode-menu' (thus also cleaning
+      ;; up `yas-minor-mode-map', which points to it)
+      ;;
+      (maphash #'(lambda (menu-symbol _keymap)
+                   (define-key yas--minor-mode-menu (vector menu-symbol) nil))
+               yas--menu-table)
+      ;; Now empty `yas--menu-table' as well
+      (setq yas--menu-table (make-hash-table))
+
+      ;; Cancel all pending 'yas--scheduled-jit-loads'
+      ;;
+      (setq yas--scheduled-jit-loads (make-hash-table))
+
+      ;; Reload the directories listed in `yas-snippet-dirs' or prompt
+      ;; the user to select one.
+      ;;
+      (setq errors (yas--load-snippet-dirs no-jit))
+      ;; Reload the direct keybindings
+      ;;
+      (yas-direct-keymaps-reload)
+
+      (run-hooks 'yas-after-reload-hook)
+      (let ((no-snippets
+             (cl-every (lambda (table) (= (hash-table-count table) 0))
+                       (list yas--scheduled-jit-loads
+                             yas--parents yas--tables))))
+        (yas--message (if (or no-snippets errors) 2 3)
+                      (if no-jit "Snippets loaded %s."
+                        "Prepared just-in-time loading of snippets %s.")
+                      (cond (errors
+                             "with some errors.  Check *Messages*")
+                            (no-snippets
+                             "(but no snippets found)")
+                            (t
+                             "successfully")))))))
+
+(defvar yas-after-reload-hook nil
+  "Hooks run after `yas-reload-all'.")
+
+(defun yas--load-pending-jits ()
+  (dolist (mode (yas--modes-to-activate))
+    (let ((funs (reverse (gethash mode yas--scheduled-jit-loads))))
+      ;; must reverse to maintain coherence with `yas-snippet-dirs'
+      (dolist (fun funs)
+        (yas--message 4 "Loading for `%s', just-in-time: %s!" mode fun)
+        (funcall fun))
+      (remhash mode yas--scheduled-jit-loads))))
+
+(defun yas-escape-text (text)
+  "Escape TEXT for snippet."
+  (when text
+    (replace-regexp-in-string "[\\$]" "\\\\\\&" text)))
+
+
+;;; Snippet compilation function
+
+(defun yas-compile-directory (top-level-dir)
+  "Create .yas-compiled-snippets.el files under subdirs of TOP-LEVEL-DIR.
+
+This works by stubbing a few functions, then calling
+`yas-load-directory'."
+  (interactive "DTop level snippet directory?")
+  (let ((yas--creating-compiled-snippets t))
+    (yas-load-directory top-level-dir nil)))
+
+(defun yas-recompile-all ()
+  "Compile every dir in `yas-snippet-dirs'."
+  (interactive)
+  (mapc #'yas-compile-directory (yas-snippet-dirs)))
+
+
+;;; JIT loading
+;;;
+
+(defvar yas--scheduled-jit-loads (make-hash-table)
+  "Alist of mode-symbols to forms to be evaled when `yas-minor-mode' kicks in.")
+
+(defun yas--schedule-jit (mode fun)
+  (push fun (gethash mode yas--scheduled-jit-loads)))
+
+
+
+;;; Some user level functions
+
+(defun yas-about ()
+  (interactive)
+  (message "yasnippet (version %s) -- pluskid/joaotavora/npostavs"
+           (or (ignore-errors (car (let ((default-directory yas--loaddir))
+                                     (process-lines "git" "describe"
+                                                    "--tags" "--dirty"))))
+               (when (and (featurep 'package)
+                          (fboundp 'package-desc-version)
+                          (fboundp 'package-version-join))
+                 (defvar package-alist)
+                 (ignore-errors
+                   (let* ((yas-pkg (cdr (assq 'yasnippet package-alist)))
+                          (version (package-version-join
+                                    (package-desc-version (car yas-pkg)))))
+                     ;; Special case for MELPA's bogus version numbers.
+                     (if (string-match "\\`20..[01][0-9][0-3][0-9][.][0-9]\\{3,4\\}\\'"
+                                       version)
+                         (concat yas--version "-snapshot" version)
+                       version))))
+               yas--version)))
+
+
+;;; Apropos snippet menu:
+;;
+;; The snippet menu keymaps are stored by mode in hash table called
+;; `yas--menu-table'. They are linked to the main menu in
+;; `yas--menu-keymap-get-create' and are initially created empty,
+;; reflecting the table hierarchy.
+;;
+;; They can be populated in two mutually exclusive ways: (1) by
+;; reading `yas--template-group', which in turn is populated by the "#
+;; group:" directives of the snippets or the ".yas-make-groups" file
+;; or (2) by using a separate `yas-define-menu' call, which declares a
+;; menu structure based on snippets uuids.
+;;
+;; Both situations are handled in `yas--update-template-menu', which
+;; uses the predicate `yas--template-menu-managed-by-yas-define-menu'
+;; that can tell between the two situations.
+;;
+;; Note:
+;;
+;; * if `yas-define-menu' is used it must run before
+;;   `yas-define-snippets' and the UUIDS must match, otherwise we get
+;;   duplicate entries. The `yas--template' objects are created in
+;;   `yas-define-menu', holding nothing but the menu entry,
+;;   represented by a pair of ((menu-item NAME :keys KEYS) TYPE) and
+;;   stored in `yas--template-menu-binding-pair'.  The (menu-item ...)
+;;   part is then stored in the menu keymap itself which make the item
+;;   appear to the user.  These limitations could probably be revised.
+;;
+;; * The `yas--template-perm-group' slot is only used in
+;;   `yas-describe-tables'.
+;;
+(defun yas--template-menu-binding-pair-get-create (template &optional type)
+  "Get TEMPLATE's menu binding or assign it a new one.
+
+TYPE may be `:stay', signaling this menu binding should be
+static in the menu."
+  (or (yas--template-menu-binding-pair template)
+      (let (;; (key (yas--template-key template))
+            ;; (keybinding (yas--template-keybinding template))
+            )
+        (setf (yas--template-menu-binding-pair template)
+              (cons `(menu-item ,(or (yas--template-name template)
+                                     (yas--template-uuid template))
+                                ,(yas--make-menu-binding template)
+                                :keys ,nil)
+                    type)))))
+(defun yas--template-menu-managed-by-yas-define-menu (template)
+  "Non-nil if TEMPLATE's menu entry was included in a `yas-define-menu' call."
+  (cdr (yas--template-menu-binding-pair template)))
+
+
+(defun yas--show-menu-p (mode)
+  (cond ((eq yas-use-menu 'abbreviate)
+         (cl-find mode
+                  (mapcar #'yas--table-mode
+                          (yas--get-snippet-tables))))
+        (yas-use-menu t)))
+
+(defun yas--delete-from-keymap (keymap uuid)
+  "Recursively delete items with UUID from KEYMAP and its submenus."
+
+  ;; XXX: This used to skip any submenus named \"parent mode\"
+  ;;
+  ;; First of all, recursively enter submenus, i.e. the tree is
+  ;; searched depth first so that stale submenus can be found in the
+  ;; higher passes.
+  ;;
+  (mapc #'(lambda (item)
+            (when (and (consp (cdr-safe item))
+                       (keymapp (nth 2 (cdr item))))
+              (yas--delete-from-keymap (nth 2 (cdr item)) uuid)))
+        (cdr keymap))
+  ;; Set the uuid entry to nil
+  ;;
+  (define-key keymap (vector (make-symbol uuid)) nil)
+  ;; Destructively modify keymap
+  ;;
+  (setcdr keymap (cl-delete-if (lambda (item)
+                                 (cond ((not (listp item)) nil)
+                                       ((null (cdr item)))
+                                       ((and (keymapp (nth 2 (cdr item)))
+                                             (null (cdr (nth 2 (cdr item))))))))
+                               (cdr keymap))))
+
+(defun yas-define-menu (mode menu &optional omit-items)
+  "Define a snippet menu for MODE according to MENU, omitting OMIT-ITEMS.
+
+MENU is a list, its elements can be:
+
+- (yas-item UUID) : Creates an entry the snippet identified with
+  UUID.  The menu entry for a snippet thus identified is
+  permanent, i.e. it will never move (be reordered) in the menu.
+
+- (yas-separator) : Creates a separator
+
+- (yas-submenu NAME SUBMENU) : Creates a submenu with NAME,
+  SUBMENU has the same form as MENU.  NAME is also added to the
+  list of groups of the snippets defined thereafter.
+
+OMIT-ITEMS is a list of snippet uuids that will always be
+omitted from MODE's menu, even if they're manually loaded."
+  (let* ((table (yas--table-get-create mode))
+         (hash (yas--table-uuidhash table)))
+    (yas--define-menu-1 table
+                        (yas--menu-keymap-get-create mode)
+                        menu
+                        hash)
+    (dolist (uuid omit-items)
+      (let ((template (or (gethash uuid hash)
+                          (puthash uuid
+                                   (yas--make-template :table table
+                                                       :uuid uuid)
+                                   hash))))
+        (setf (yas--template-menu-binding-pair template) (cons nil :none))))))
+
+(defun yas--define-menu-1 (table menu-keymap menu uuidhash &optional group-list)
+  "Helper for `yas-define-menu'."
+  (cl-loop
+   for (type name submenu) in (reverse menu)
+   collect (cond
+            ((or (eq type 'yas-item)
+                 (and yas-alias-to-yas/prefix-p
+                      (eq type 'yas/item)))
+             (let ((template (or (gethash name uuidhash)
+                                 (puthash name
+                                          (yas--make-template
+                                           :table table
+                                           :perm-group group-list
+                                           :uuid name)
+                                          uuidhash))))
+               (car (yas--template-menu-binding-pair-get-create
+                     template :stay))))
+            ((or (eq type 'yas-submenu)
+                 (and yas-alias-to-yas/prefix-p
+                      (eq type 'yas/submenu)))
+             (let ((subkeymap (make-sparse-keymap)))
+               (yas--define-menu-1 table subkeymap submenu uuidhash
+                                   (append group-list (list name)))
+               `(menu-item ,name ,subkeymap)))
+            ((or (eq type 'yas-separator)
+                 (and yas-alias-to-yas/prefix-p
+                      (eq type 'yas/separator)))
+             '(menu-item "----"))
+            (t (yas--message 1 "Don't know anything about menu entry %s" type)
+               nil))
+   into menu-entries
+   finally do (push (apply #'vector menu-entries) (cdr menu-keymap))))
+
+(defun yas--define (mode key template &optional name condition group)
+  "Define a snippet.  Expanding KEY into TEMPLATE.
+
+NAME is a description to this template.  Also update the menu if
+`yas-use-menu' is t.  CONDITION is the condition attached to
+this snippet.  If you attach a condition to a snippet, then it
+will only be expanded when the condition evaluated to non-nil."
+  (yas-define-snippets mode
+                       (list (list key template name condition group))))
+
+(defun yas-hippie-try-expand (first-time?)
+  "Integrate with hippie expand.
+
+Just put this function in `hippie-expand-try-functions-list'."
+  (when yas-minor-mode
+    (if (not first-time?)
+        (let ((yas-fallback-behavior 'return-nil))
+          (yas-expand))
+      (undo 1)
+      nil)))
+
+
+;;; Apropos condition-cache:
+;;;
+;;;
+;;;
+;;;
+(defmacro yas-define-condition-cache (func doc &rest body)
+  "Define a function FUNC with doc DOC and body BODY.
+BODY is executed at most once every snippet expansion attempt, to check
+expansion conditions.
+
+It doesn't make any sense to call FUNC programatically."
+  `(defun ,func () ,(if (and doc
+                             (stringp doc))
+                        (concat doc
+"\n\nFor use in snippets' conditions. Within each
+snippet-expansion routine like `yas-expand', computes actual
+value for the first time then always returns a cached value.")
+                      (setq body (cons doc body))
+                      nil)
+     (let ((timestamp-and-value (get ',func 'yas--condition-cache)))
+       (if (equal (car timestamp-and-value) yas--condition-cache-timestamp)
+           (cdr timestamp-and-value)
+         (let ((new-value (progn
+                            ,@body
+                            )))
+           (put ',func 'yas--condition-cache (cons yas--condition-cache-timestamp new-value))
+           new-value)))))
+
+(defalias 'yas-expand 'yas-expand-from-trigger-key)
+(defun yas-expand-from-trigger-key (&optional field)
+  "Expand a snippet before point.
+
+If no snippet expansion is possible, fall back to the behaviour
+defined in `yas-fallback-behavior'.
+
+Optional argument FIELD is for non-interactive use and is an
+object satisfying `yas--field-p' to restrict the expansion to."
+  (interactive)
+  (setq yas--condition-cache-timestamp (current-time))
+  (let (templates-and-pos)
+    (unless (and yas-expand-only-for-last-commands
+                 (not (member last-command yas-expand-only-for-last-commands)))
+      (setq templates-and-pos (if field
+                                  (save-restriction
+                                    (narrow-to-region (yas--field-start field)
+                                                      (yas--field-end field))
+                                    (yas--templates-for-key-at-point))
+                                (yas--templates-for-key-at-point))))
+    (if templates-and-pos
+        (yas--expand-or-prompt-for-template
+         (nth 0 templates-and-pos)
+         ;; Delete snippet key and active region when expanding.
+         (min (if (use-region-p) (region-beginning) most-positive-fixnum)
+              (nth 1 templates-and-pos))
+         (max (if (use-region-p) (region-end) most-negative-fixnum)
+              (nth 2 templates-and-pos)))
+      (yas--fallback))))
+
+(defun yas--maybe-expand-from-keymap-filter (cmd)
+  (let* ((yas--condition-cache-timestamp (current-time))
+         (vec (cl-subseq (this-command-keys-vector)
+                         (if current-prefix-arg
+                             (length (this-command-keys))
+                           0)))
+         (templates (cl-mapcan (lambda (table)
+                                 (yas--fetch table vec))
+                               (yas--get-snippet-tables))))
+    (if templates (or cmd templates))))
+
+(defun yas-expand-from-keymap ()
+  "Directly expand some snippets, searching `yas--direct-keymaps'."
+  (interactive)
+  (setq yas--condition-cache-timestamp (current-time))
+  (let* ((templates (yas--maybe-expand-from-keymap-filter nil)))
+    (when templates
+      (yas--expand-or-prompt-for-template templates))))
+
+(defun yas--expand-or-prompt-for-template (templates &optional start end)
+  "Expand one of TEMPLATES from START to END.
+
+Prompt the user if TEMPLATES has more than one element, else
+expand immediately.  Common gateway for
+`yas-expand-from-trigger-key' and `yas-expand-from-keymap'."
+  (let ((yas--current-template (or (and (cl-rest templates) ;; more than one
+                                        (yas--prompt-for-template (mapcar #'cdr templates)))
+                                   (cdar templates))))
+    (when yas--current-template
+      (yas-expand-snippet (yas--template-content yas--current-template)
+                          start
+                          end
+                          (yas--template-expand-env yas--current-template)))))
+
+;; Apropos the trigger key and the fallback binding:
+;;
+;; When `yas-minor-mode-map' binds <tab>, that correctly overrides
+;; org-mode's <tab>, for example and searching for fallbacks correctly
+;; returns `org-cycle'. However, most other modes bind "TAB". TODO,
+;; improve this explanation.
+;;
+(defun yas--fallback ()
+  "Fallback after expansion has failed.
+
+Common gateway for `yas-expand-from-trigger-key' and
+`yas-expand-from-keymap'."
+  (cond ((eq yas-fallback-behavior 'return-nil)
+         ;; return nil
+         nil)
+        ((eq yas-fallback-behavior 'yas--fallback)
+         (error (concat "yasnippet fallback loop!\n"
+                        "This can happen when you bind `yas-expand' "
+                        "outside of the `yas-minor-mode-map'.")))
+        ((eq yas-fallback-behavior 'call-other-command)
+         (let* ((yas-fallback-behavior 'yas--fallback)
+                ;; Also bind `yas-minor-mode' to prevent fallback
+                ;; loops when other extensions use mechanisms similar
+                ;; to `yas--keybinding-beyond-yasnippet'. (github #525
+                ;; and #526)
+                ;;
+                (yas-minor-mode nil)
+                (beyond-yasnippet (yas--keybinding-beyond-yasnippet)))
+           (yas--message 4 "Falling back to %s"  beyond-yasnippet)
+           (cl-assert (or (null beyond-yasnippet) (commandp beyond-yasnippet)))
+           (setq this-command beyond-yasnippet)
+           (when beyond-yasnippet
+             (call-interactively beyond-yasnippet))))
+        ((and (listp yas-fallback-behavior)
+              (cdr yas-fallback-behavior)
+              (eq 'apply (car yas-fallback-behavior)))
+         (let ((command-or-fn (cadr yas-fallback-behavior))
+               (args (cddr yas-fallback-behavior))
+               (yas-fallback-behavior 'yas--fallback)
+               (yas-minor-mode nil))
+           (if args
+               (apply command-or-fn args)
+             (when (commandp command-or-fn)
+               (setq this-command command-or-fn)
+               (call-interactively command-or-fn)))))
+        (t
+         ;; also return nil if all the other fallbacks have failed
+         nil)))
+
+(defun yas--keybinding-beyond-yasnippet ()
+  "Get current keys's binding as if YASsnippet didn't exist."
+  (let* ((yas-minor-mode nil)
+         (yas--direct-keymaps nil)
+         (keys (this-single-command-keys)))
+    (or (key-binding keys t)
+        (key-binding (yas--fallback-translate-input keys) t))))
+
+(defun yas--fallback-translate-input (keys)
+  "Emulate `read-key-sequence', at least what I think it does.
+
+Keys should be an untranslated key vector.  Returns a translated
+vector of keys.  FIXME not thoroughly tested."
+  (let ((retval [])
+        (i 0))
+    (while (< i (length keys))
+      (let ((j i)
+            (translated local-function-key-map))
+        (while (and (< j (length keys))
+                    translated
+                    (keymapp translated))
+          (setq translated (cdr (assoc (aref keys j) (remove 'keymap translated)))
+                j (1+ j)))
+        (setq retval (vconcat retval (cond ((symbolp translated)
+                                            `[,translated])
+                                           ((vectorp translated)
+                                            translated)
+                                           (t
+                                            (substring keys i j)))))
+        (setq i j)))
+    retval))
+
+
+;;; Utils for snippet development:
+
+(defun yas--all-templates (tables)
+  "Get `yas--template' objects in TABLES, applicable for buffer and point.
+
+Honours `yas-choose-tables-first', `yas-choose-keys-first' and
+`yas-buffer-local-condition'"
+  (when yas-choose-tables-first
+    (setq tables (list (yas--prompt-for-table tables))))
+  (mapcar #'cdr
+          (if yas-choose-keys-first
+              (let ((key (yas--prompt-for-keys
+                          (cl-mapcan #'yas--table-all-keys tables))))
+                (when key
+                  (cl-mapcan (lambda (table)
+                               (yas--fetch table key))
+                             tables)))
+            (cl-remove-duplicates (cl-mapcan #'yas--table-templates tables)
+                                  :test #'equal))))
+
+(defun yas--lookup-snippet-1 (name mode)
+  "Get the snippet called NAME in MODE's tables."
+  (let ((yas-choose-tables-first nil)   ; avoid prompts
+        (yas-choose-keys-first nil))
+    (cl-find name (yas--all-templates
+                   (yas--get-snippet-tables mode))
+             :key #'yas--template-name :test #'string=)))
+
+(defun yas-lookup-snippet (name &optional mode noerror)
+  "Get the snippet named NAME in MODE's tables.
+
+MODE defaults to the current buffer's `major-mode'.  If NOERROR
+is non-nil, then don't signal an error if there isn't any snippet
+called NAME.
+
+Honours `yas-buffer-local-condition'."
+  (cond
+   ((yas--lookup-snippet-1 name mode))
+   (noerror nil)
+   (t (error "No snippet named: %s" name))))
+
+(defun yas-insert-snippet (&optional no-condition)
+  "Choose a snippet to expand, pop-up a list of choices according
+to `yas-prompt-functions'.
+
+With prefix argument NO-CONDITION, bypass filtering of snippets
+by condition."
+  (interactive "P")
+  (setq yas--condition-cache-timestamp (current-time))
+  (let* ((yas-buffer-local-condition (or (and no-condition
+                                              'always)
+                                         yas-buffer-local-condition))
+         (templates (yas--all-templates (yas--get-snippet-tables)))
+         (yas--current-template (and templates
+                                    (or (and (cl-rest templates) ;; more than one template for same key
+                                             (yas--prompt-for-template templates))
+                                        (car templates))))
+         (where (if (region-active-p)
+                    (cons (region-beginning) (region-end))
+                  (cons (point) (point)))))
+    (if yas--current-template
+        (yas-expand-snippet (yas--template-content yas--current-template)
+                            (car where)
+                            (cdr where)
+                            (yas--template-expand-env yas--current-template))
+      (yas--message 1 "No snippets can be inserted here!"))))
+
+(defun yas-visit-snippet-file ()
+  "Choose a snippet to edit, selection like `yas-insert-snippet'.
+
+Only success if selected snippet was loaded from a file.  Put the
+visited file in `snippet-mode'."
+  (interactive)
+  (let* ((yas-buffer-local-condition 'always)
+         (templates (yas--all-templates (yas--get-snippet-tables)))
+         (template (and templates
+                        (or (yas--prompt-for-template templates
+                                                     "Choose a snippet template to edit: ")
+                            (car templates)))))
+
+    (if template
+        (yas--visit-snippet-file-1 template)
+      (message "No snippets tables active!"))))
+
+(defun yas--visit-snippet-file-1 (template)
+  "Helper for `yas-visit-snippet-file'."
+  (let ((file (yas--template-get-file template)))
+    (cond ((and file (file-readable-p file))
+           (find-file-other-window file)
+           (snippet-mode)
+           (set (make-local-variable 'yas--editing-template) template))
+          (file
+           (message "Original file %s no longer exists!" file))
+          (t
+           (switch-to-buffer (format "*%s*"(yas--template-name template)))
+           (let ((type 'snippet))
+             (when (listp (yas--template-content template))
+               (insert (format "# type: command\n"))
+               (setq type 'command))
+             (insert (format "# key: %s\n" (yas--template-key template)))
+             (insert (format "# name: %s\n" (yas--template-name template)))
+             (when (yas--template-keybinding template)
+               (insert (format "# binding: %s\n" (yas--template-keybinding template))))
+             (when (yas--template-expand-env template)
+               (insert (format "# expand-env: %s\n" (yas--template-expand-env template))))
+             (when (yas--template-condition template)
+               (insert (format "# condition: %s\n" (yas--template-condition template))))
+             (insert "# --\n")
+             (insert (if (eq type 'command)
+                         (pp-to-string (yas--template-content template))
+                       (yas--template-content template))))
+           (snippet-mode)
+           (set (make-local-variable 'yas--editing-template) template)
+           (set (make-local-variable 'default-directory)
+                (car (cdr (car (yas--guess-snippet-directories (yas--template-table template))))))))))
+
+(defun yas--guess-snippet-directories-1 (table)
+  "Guess possible snippet subdirectories for TABLE."
+  (cons (file-name-as-directory (yas--table-name table))
+        (cl-mapcan #'yas--guess-snippet-directories-1
+                   (yas--table-parents table))))
+
+(defun yas--guess-snippet-directories (&optional table)
+  "Try to guess suitable directories based on the current active
+tables (or optional TABLE).
+
+Returns a list of elements (TABLE . DIRS) where TABLE is a
+`yas--table' object and DIRS is a list of all possible directories
+where snippets of table might exist."
+  (let ((main-dir (car (or (yas-snippet-dirs)
+                           (setq yas-snippet-dirs
+                                 (list yas--default-user-snippets-dir)))))
+        (tables (if table (list table)
+                  (yas--get-snippet-tables))))
+    ;; HACK! the snippet table created here is actually registered!
+    (unless table
+      ;; The major mode is probably the best guess, put it first.
+      (let ((major-mode-table (yas--table-get-create major-mode)))
+        (cl-callf2 delq major-mode-table tables)
+        (push major-mode-table tables)))
+
+    (mapcar #'(lambda (table)
+                (cons table
+                      (mapcar #'(lambda (subdir)
+                                  (expand-file-name subdir main-dir))
+                              (yas--guess-snippet-directories-1 table))))
+            tables)))
+
+(defun yas--make-directory-maybe (table-and-dirs &optional main-table-string)
+  "Return a dir inside TABLE-AND-DIRS, prompts for creation if none exists."
+  (or (cl-some (lambda (dir) (when (file-directory-p dir) dir))
+               (cdr table-and-dirs))
+      (let ((candidate (cl-first (cdr table-and-dirs))))
+        (unless (file-writable-p (file-name-directory candidate))
+          (error (yas--format "%s is not writable." candidate)))
+        (if (y-or-n-p (format "Guessed directory (%s) for%s%s table \"%s\" does not exist! Create? "
+                              candidate
+                              (if (gethash (yas--table-mode (car table-and-dirs))
+                                           yas--tables)
+                                  ""
+                                " brand new")
+                              (or main-table-string
+                                  "")
+                              (yas--table-name (car table-and-dirs))))
+            (progn
+              (make-directory candidate 'also-make-parents)
+              ;; create the .yas-parents file here...
+              candidate)))))
+
+;; NOTE: Using the traditional "*new snippet*" stops whitespace mode
+;; from activating (it doesn't like the leading "*").
+(defconst yas-new-snippet-buffer-name "+new-snippet+")
+
+(defun yas-new-snippet (&optional no-template)
+  "Pops a new buffer for writing a snippet.
+
+Expands a snippet-writing snippet, unless the optional prefix arg
+NO-TEMPLATE is non-nil."
+  (interactive "P")
+  (let ((guessed-directories (yas--guess-snippet-directories))
+        (yas-selected-text (or yas-selected-text
+                               (and (region-active-p)
+                                    (buffer-substring-no-properties
+                                     (region-beginning) (region-end))))))
+
+    (switch-to-buffer yas-new-snippet-buffer-name)
+    (erase-buffer)
+    (kill-all-local-variables)
+    (snippet-mode)
+    (yas-minor-mode 1)
+    (set (make-local-variable 'yas--guessed-modes)
+         (mapcar (lambda (d) (yas--table-mode (car d)))
+                 guessed-directories))
+    (set (make-local-variable 'default-directory)
+         (car (cdr (car guessed-directories))))
+    (if (and (not no-template) yas-new-snippet-default)
+        (yas-expand-snippet yas-new-snippet-default))))
+
+(defun yas--compute-major-mode-and-parents (file)
+  "Given FILE, find the nearest snippet directory for a given mode.
+
+Returns a list (MODE-SYM PARENTS), the mode's symbol and a list
+representing one or more of the mode's parents.
+
+Note that MODE-SYM need not be the symbol of a real major mode,
+neither do the elements of PARENTS."
+  (let* ((file-dir (and file
+                        (directory-file-name
+                         (or (cl-some (lambda (special)
+                                        (locate-dominating-file file special))
+                                      '(".yas-setup.el"
+                                        ".yas-make-groups"
+                                        ".yas-parents"))
+                             (directory-file-name (file-name-directory file))))))
+         (parents-file-name (concat file-dir "/.yas-parents"))
+         (major-mode-name (and file-dir
+                               (file-name-nondirectory file-dir)))
+         (major-mode-sym (or (and major-mode-name
+                                  (intern major-mode-name))))
+         (parents (when (file-readable-p parents-file-name)
+                         (mapcar #'intern
+                                 (split-string
+                                  (with-temp-buffer
+                                    (insert-file-contents parents-file-name)
+                                    (buffer-substring-no-properties (point-min)
+                                                                    (point-max))))))))
+    (when major-mode-sym
+      (cons major-mode-sym (remove major-mode-sym parents)))))
+
+(defvar yas--editing-template nil
+  "Supporting variable for `yas-load-snippet-buffer' and `yas--visit-snippet'.")
+
+(defvar yas--current-template nil
+  "Holds the current template being expanded into a snippet.")
+
+(defvar yas--guessed-modes nil
+  "List of guessed modes supporting `yas-load-snippet-buffer'.")
+
+(defun yas--read-table ()
+  "Ask user for a snippet table, help with some guessing."
+  (let ((prompt (if (and (featurep 'ido)
+                         ido-mode)
+                    'ido-completing-read 'completing-read)))
+    (unless yas--guessed-modes
+      (set (make-local-variable 'yas--guessed-modes)
+           (or (yas--compute-major-mode-and-parents buffer-file-name))))
+    (intern
+     (funcall prompt (format "Choose or enter a table (yas guesses %s): "
+                             (if yas--guessed-modes
+                                 (cl-first yas--guessed-modes)
+                               "nothing"))
+              (mapcar #'symbol-name yas--guessed-modes)
+              nil
+              nil
+              nil
+              nil
+              (if (cl-first yas--guessed-modes)
+                  (symbol-name (cl-first yas--guessed-modes)))))))
+
+(defun yas-load-snippet-buffer (table &optional interactive)
+  "Parse and load current buffer's snippet definition into TABLE.
+TABLE is a symbol name passed to `yas--table-get-create'.  When
+called interactively, prompt for the table name.
+Return the `yas--template' object created"
+  (interactive (list (yas--read-table) t))
+  (cond
+   ;;  We have `yas--editing-template', this buffer's content comes from a
+   ;;  template which is already loaded and neatly positioned,...
+   ;;
+   (yas--editing-template
+    (yas--define-snippets-1 (yas--parse-template (yas--template-load-file yas--editing-template))
+                           (yas--template-table yas--editing-template)))
+   ;; Try to use `yas--guessed-modes'. If we don't have that use the
+   ;; value from `yas--compute-major-mode-and-parents'
+   ;;
+   (t
+    (unless yas--guessed-modes
+      (set (make-local-variable 'yas--guessed-modes) (or (yas--compute-major-mode-and-parents buffer-file-name))))
+    (let* ((table (yas--table-get-create table)))
+      (set (make-local-variable 'yas--editing-template)
+           (yas--define-snippets-1 (yas--parse-template buffer-file-name)
+                                  table)))))
+  (when interactive
+    (yas--message 3 "Snippet \"%s\" loaded for %s."
+                  (yas--template-name yas--editing-template)
+                  (yas--table-name (yas--template-table yas--editing-template))))
+  yas--editing-template)
+
+(defun yas-maybe-load-snippet-buffer ()
+  "Added to `after-save-hook' in `snippet-mode'."
+  (let* ((mode (intern (file-name-sans-extension
+                        (file-name-nondirectory
+                         (directory-file-name default-directory)))))
+         (current-snippet
+          (apply #'yas--define-snippets-2 (yas--table-get-create mode)
+                 (yas--parse-template buffer-file-name)))
+         (uuid (yas--template-uuid current-snippet)))
+    (unless (equal current-snippet
+                   (if uuid (yas--get-template-by-uuid mode uuid)
+                     (yas--lookup-snippet-1
+                      (yas--template-name current-snippet) mode)))
+      (yas-load-snippet-buffer mode t))))
+
+(defun yas-load-snippet-buffer-and-close (table &optional kill)
+  "Load and save the snippet, then `quit-window' if saved.
+Loading is performed by `yas-load-snippet-buffer'.  If the
+snippet is new, ask the user whether (and where) to save it.  If
+the snippet already has a file, just save it.
+
+The prefix argument KILL is passed to `quit-window'.
+
+Don't use this from a Lisp program, call `yas-load-snippet-buffer'
+and `kill-buffer' instead."
+  (interactive (list (yas--read-table) current-prefix-arg))
+  (let ((template (yas-load-snippet-buffer table t)))
+    (when (and (buffer-modified-p)
+               (y-or-n-p
+                (format "[yas] Loaded for %s. Also save snippet buffer?"
+                        (yas--table-name (yas--template-table template)))))
+      (let ((default-directory (car (cdr (car (yas--guess-snippet-directories
+                                               (yas--template-table template))))))
+            (default-file-name (yas--template-name template)))
+        (unless (or buffer-file-name (not default-file-name))
+          (setq buffer-file-name
+                (read-file-name "File to save snippet in: "
+                                nil nil nil default-file-name))
+          (rename-buffer (file-name-nondirectory buffer-file-name) t))
+        (save-buffer)))
+    (quit-window kill)))
+
+(declare-function yas-debug-snippets "yasnippet-debug")
+
+(defun yas-tryout-snippet (&optional debug)
+  "Test current buffer's snippet template in other buffer.
+DEBUG is for debugging the YASnippet engine itself."
+  (interactive "P")
+  (let* ((major-mode-and-parent (yas--compute-major-mode-and-parents buffer-file-name))
+         (parsed (yas--parse-template))
+         (test-mode (or (and (car major-mode-and-parent)
+                             (fboundp (car major-mode-and-parent))
+                             (car major-mode-and-parent))
+                        (cl-first yas--guessed-modes)
+                        (intern (read-from-minibuffer (yas--format "Please input a mode: ")))))
+         (yas--current-template
+          (and parsed
+               (fboundp test-mode)
+               (yas--make-template :table       nil ;; no tables for ephemeral snippets
+                                   :key         (nth 0 parsed)
+                                   :content     (nth 1 parsed)
+                                   :name        (nth 2 parsed)
+                                   :expand-env  (nth 5 parsed)))))
+    (cond (yas--current-template
+           (let ((buffer-name (format "*testing snippet: %s*" (yas--template-name yas--current-template))))
+             (kill-buffer (get-buffer-create buffer-name))
+             (switch-to-buffer (get-buffer-create buffer-name))
+             (setq buffer-undo-list nil)
+             (condition-case nil (funcall test-mode) (error nil))
+	     (yas-minor-mode 1)
+             (setq buffer-read-only nil)
+             (yas-expand-snippet (yas--template-content yas--current-template)
+                                 (point-min)
+                                 (point-max)
+                                 (yas--template-expand-env yas--current-template))
+             (when (and debug
+                        (require 'yasnippet-debug nil t))
+               (yas-debug-snippets "*YASnippet trace*" 'snippet-navigation)
+               (display-buffer "*YASnippet trace*"))))
+          (t
+           (yas--message 1 "Cannot test snippet for unknown major mode")))))
+
+(defun yas-active-keys ()
+  "Return all active trigger keys for current buffer and point."
+  (cl-remove-duplicates
+   (cl-remove-if-not #'stringp (cl-mapcan #'yas--table-all-keys
+                                          (yas--get-snippet-tables)))
+   :test #'string=))
+
+(defun yas--template-fine-group (template)
+  (car (last (or (yas--template-group template)
+                 (yas--template-perm-group template)))))
+
+(defun yas-describe-table-by-namehash ()
+  "Display snippet tables by NAMEHASH."
+  (interactive)
+  (with-current-buffer (get-buffer-create "*YASnippet Tables by NAMEHASH*")
+    (let ((inhibit-read-only t))
+      (erase-buffer)
+      (insert "YASnippet tables by NAMEHASH: \n")
+      (maphash
+       (lambda (_mode table)
+         (insert (format "\nSnippet table `%s':\n\n" (yas--table-name table)))
+         (maphash
+          (lambda (key _v)
+            (insert (format "   key %s maps snippets: %s\n" key
+                            (let ((names))
+                              (maphash #'(lambda (k _v)
+                                           (push k names))
+                                       (gethash key (yas--table-hash table)))
+                              names))))
+          (yas--table-hash table)))
+       yas--tables))
+    (view-mode +1)
+    (goto-char 1)
+    (display-buffer (current-buffer))))
+
+(defun yas-describe-tables (&optional with-nonactive)
+  "Display snippets for each table."
+  (interactive "P")
+  (let ((original-buffer (current-buffer))
+        (tables (yas--get-snippet-tables)))
+   (with-current-buffer (get-buffer-create "*YASnippet Tables*")
+     (let ((inhibit-read-only t))
+       (when with-nonactive
+         (maphash #'(lambda (_k v)
+                      (cl-pushnew v tables))
+                  yas--tables))
+       (erase-buffer)
+       (insert "YASnippet tables:\n")
+       (dolist (table tables)
+         (yas--describe-pretty-table table original-buffer))
+       (yas--create-snippet-xrefs))
+     (help-mode)
+     (goto-char 1)
+     (display-buffer (current-buffer)))))
+
+(defun yas--describe-pretty-table (table &optional original-buffer)
+  (insert (format "\nSnippet table `%s'"
+                  (yas--table-name table)))
+  (if (yas--table-parents table)
+      (insert (format " parents: %s\n"
+                      (mapcar #'yas--table-name
+                              (yas--table-parents table))))
+    (insert "\n"))
+  (insert (make-string 100 ?-) "\n")
+  (insert "group                   state name                                    key             binding\n")
+  (let ((groups-hash (make-hash-table :test #'equal)))
+    (maphash #'(lambda (_k v)
+                 (let ((group (or (yas--template-fine-group v)
+                                  "(top level)")))
+                   (when (yas--template-name v)
+                     (puthash group
+                              (cons v (gethash group groups-hash))
+                              groups-hash))))
+             (yas--table-uuidhash table))
+    (maphash
+     #'(lambda (group templates)
+         (setq group (truncate-string-to-width group 25 0 ?  "..."))
+         (insert (make-string 100 ?-) "\n")
+         (dolist (p templates)
+           (let* ((name (truncate-string-to-width (propertize (format "\\\\snippet `%s'" (yas--template-name p))
+                                                              'yasnippet p)
+                                                  50 0 ? "..."))
+                  (group (prog1 group
+                           (setq group (make-string (length group) ? ))))
+                  (condition-string (let ((condition (yas--template-condition p)))
+                                      (if (and condition
+                                               original-buffer)
+                                          (with-current-buffer original-buffer
+                                            (if (yas--eval-condition condition)
+                                                "(y)"
+                                              "(s)"))
+                                        "(a)")))
+                  (key-description-string (key-description (yas--template-keybinding p)))
+                  (template-key-padding (if (string= key-description-string "") nil ? )))
+             (insert group " "
+                     condition-string " "
+                     name (if (string-match "\\.\\.\\.$" name)
+                              "'" " ")
+                     " "
+                     (truncate-string-to-width (or (yas--template-key p) "")
+                                               15 0 template-key-padding "...")
+                     (or template-key-padding "")
+                     (truncate-string-to-width key-description-string
+                                               15 0 nil "...")
+                     "\n"))))
+     groups-hash)))
+
+
+
+;;; User convenience functions, for using in `yas-key-syntaxes'
+
+(defun yas-try-key-from-whitespace (_start-point)
+  "As `yas-key-syntaxes' element, look for whitespace delimited key.
+
+A newline will be considered whitespace even if the mode syntax
+marks it as something else (typically comment ender)."
+  (skip-chars-backward "^[:space:]\n"))
+
+(defun yas-shortest-key-until-whitespace (_start-point)
+  "Like `yas-longest-key-from-whitespace' but take the shortest key."
+  (when (/= (skip-chars-backward "^[:space:]\n" (1- (point))) 0)
+    'again))
+
+(defun yas-longest-key-from-whitespace (start-point)
+  "As `yas-key-syntaxes' element, look for longest key between point and whitespace.
+
+A newline will be considered whitespace even if the mode syntax
+marks it as something else (typically comment ender)."
+  (if (= (point) start-point)
+      (yas-try-key-from-whitespace start-point)
+    (forward-char))
+  (unless (<= start-point (1+ (point)))
+    'again))
+
+
+
+;;; User convenience functions, for using in snippet definitions
+
+(defvar yas-modified-p nil
+  "Non-nil if field has been modified by user or transformation.")
+
+(defvar yas-moving-away-p nil
+  "Non-nil if user is about to exit field.")
+
+(defvar yas-text nil
+  "Contains current field text.")
+
+(defun yas-substr (str pattern &optional subexp)
+  "Search PATTERN in STR and return SUBEXPth match.
+
+If found, the content of subexp group SUBEXP (default 0) is
+  returned, or else the original STR will be returned."
+  (let ((grp (or subexp 0)))
+    (save-match-data
+      (if (string-match pattern str)
+          (match-string-no-properties grp str)
+        str))))
+
+(defun yas-choose-value (&rest possibilities)
+  "Prompt for a string in POSSIBILITIES and return it.
+
+The last element of POSSIBILITIES may be a list of strings."
+  (unless (or yas-moving-away-p
+              yas-modified-p)
+    (let* ((last-link (last possibilities))
+           (last-elem (car last-link)))
+      (when (listp last-elem)
+        (setcar last-link (car last-elem))
+        (setcdr last-link (cdr last-elem))))
+    (cl-some (lambda (fn)
+               (funcall fn "Choose: " possibilities))
+             yas-prompt-functions)))
+
+(defun yas--auto-next ()
+  "Helper for `yas-auto-next'."
+  (remove-hook 'post-command-hook #'yas--auto-next t)
+  (yas-next-field))
+
+(defmacro yas-auto-next (&rest body)
+  "Automatically advance to next field after eval'ing BODY."
+  (declare (indent 0) (debug t))
+  `(unless yas-moving-away-p
+     (prog1 ,@body
+       (add-hook 'post-command-hook #'yas--auto-next nil t))))
+
+(defun yas-key-to-value (alist)
+  (unless (or yas-moving-away-p
+              yas-modified-p)
+    (let ((key (read-key-sequence "")))
+      (when (stringp key)
+        (or (cdr (cl-find key alist :key #'car :test #'string=))
+            key)))))
+
+(defun yas-throw (text)
+  "Signal `yas-exception' with TEXT as the reason."
+  (signal 'yas-exception (list text)))
+(put 'yas-exception 'error-conditions '(error yas-exception))
+(put 'yas-exception 'error-message "[yas] Exception")
+
+(defun yas-verify-value (possibilities)
+  "Verify that the current field value is in POSSIBILITIES.
+Otherwise signal `yas-exception'."
+  (when (and yas-moving-away-p (cl-notany (lambda (pos) (string= pos yas-text)) possibilities))
+    (yas-throw (format "Field only allows %s" possibilities))))
+
+(defun yas-field-value (number)
+  "Get the string for field with NUMBER.
+
+Use this in primary and mirror transformations to get the text of
+other fields."
+  (let* ((snippet (car (yas-active-snippets)))
+         (field (and snippet
+                     (yas--snippet-find-field snippet number))))
+    (when field
+      (yas--field-text-for-display field))))
+
+(defun yas-text ()
+  "Return `yas-text' if that exists and is non-empty, else nil."
+  (if (and yas-text
+           (not (string= "" yas-text)))
+      yas-text))
+
+(defun yas-selected-text ()
+  "Return `yas-selected-text' if that exists and is non-empty, else nil."
+  (if (and yas-selected-text
+           (not (string= "" yas-selected-text)))
+      yas-selected-text))
+
+(defun yas--get-field-once (number &optional transform-fn)
+  (unless yas-modified-p
+    (if transform-fn
+        (funcall transform-fn (yas-field-value number))
+      (yas-field-value number))))
+
+(defun yas-default-from-field (number)
+  (unless yas-modified-p
+    (yas-field-value number)))
+
+(defun yas-inside-string ()
+  "Return non-nil if the point is inside a string according to font-lock."
+  (equal 'font-lock-string-face (get-char-property (1- (point)) 'face)))
+
+(defun yas-unimplemented (&optional missing-feature)
+  (if yas--current-template
+      (if (y-or-n-p (format "This snippet is unimplemented (missing %s) Visit the snippet definition? "
+                            (or missing-feature
+                                "something")))
+          (yas--visit-snippet-file-1 yas--current-template))
+    (message "No implementation. Missing %s" (or missing-feature "something"))))
+
+
+;;; Snippet expansion and field management
+
+(defvar yas--active-field-overlay nil
+  "Overlays the currently active field.")
+
+(defvar yas--active-snippets nil
+  "List of currently active snippets")
+(make-variable-buffer-local 'yas--active-snippets)
+
+(defvar yas--field-protection-overlays nil
+  "Two overlays protect the current active field.")
+
+(defvar yas-selected-text nil
+  "The selected region deleted on the last snippet expansion.")
+
+(defvar yas--start-column nil
+  "The column where the snippet expansion started.")
+
+(make-variable-buffer-local 'yas--active-field-overlay)
+(make-variable-buffer-local 'yas--field-protection-overlays)
+(put 'yas--active-field-overlay 'permanent-local t)
+(put 'yas--field-protection-overlays 'permanent-local t)
+
+(cl-defstruct (yas--snippet (:constructor yas--make-snippet (expand-env)))
+  "A snippet.
+
+..."
+  expand-env
+  (fields '())
+  (exit nil)
+  (id (yas--snippet-next-id) :read-only t)
+  (control-overlay nil)
+  active-field
+  ;; stacked expansion: the `previous-active-field' slot saves the
+  ;; active field where the child expansion took place
+  previous-active-field
+  force-exit)
+
+(cl-defstruct (yas--field (:constructor yas--make-field (number start end parent-field)))
+  "A field.
+
+NUMBER is the field number.
+START and END are mostly buffer markers, but see \"apropos markers-to-points\".
+PARENT-FIELD is a `yas--field' this field is nested under, or nil.
+MIRRORS is a list of `yas--mirror's
+TRANSFORM is a lisp form.
+MODIFIED-P is a boolean set to true once user inputs text.
+NEXT is another `yas--field' or `yas--mirror' or `yas--exit'.
+"
+  number
+  start end
+  parent-field
+  (mirrors '())
+  (transform nil)
+  (modified-p nil)
+  next)
+
+
+(cl-defstruct (yas--mirror (:constructor yas--make-mirror (start end transform)))
+  "A mirror.
+
+START and END are mostly buffer markers, but see \"apropos markers-to-points\".
+TRANSFORM is a lisp form.
+PARENT-FIELD is a `yas--field' this mirror is nested under, or nil.
+NEXT is another `yas--field' or `yas--mirror' or `yas--exit'
+DEPTH is a count of how many nested mirrors can affect this mirror"
+  start end
+  (transform nil)
+  parent-field
+  next
+  depth)
+
+(cl-defstruct (yas--exit (:constructor yas--make-exit (marker)))
+  marker
+  next)
+
+(defmacro yas--letenv (env &rest body)
+  "Evaluate BODY with bindings from ENV.
+ENV is a lisp expression that evaluates to list of elements with
+the form (VAR FORM), where VAR is a symbol and FORM is a lisp
+expression that evaluates to its value."
+  (declare (debug (form body)) (indent 1))
+  (let ((envvar (make-symbol "envvar")))
+    `(let ((,envvar ,env))
+       (cl-progv
+           (mapcar #'car ,envvar)
+           (mapcar (lambda (v-f) (eval (cadr v-f))) ,envvar)
+         ,@body))))
+
+(defun yas--snippet-map-markers (fun snippet)
+  "Apply FUN to all marker (sub)fields in SNIPPET.
+Update each field with the result of calling FUN."
+  (dolist (field (yas--snippet-fields snippet))
+    (setf (yas--field-start field) (funcall fun (yas--field-start field)))
+    (setf (yas--field-end field)   (funcall fun (yas--field-end field)))
+    (dolist (mirror (yas--field-mirrors field))
+      (setf (yas--mirror-start mirror) (funcall fun (yas--mirror-start mirror)))
+      (setf (yas--mirror-end mirror)   (funcall fun (yas--mirror-end mirror)))))
+  (let ((snippet-exit (yas--snippet-exit snippet)))
+    (when snippet-exit
+      (setf (yas--exit-marker snippet-exit)
+            (funcall fun (yas--exit-marker snippet-exit))))))
+
+(defun yas--snippet-live-p (snippet)
+  "Return non-nil if SNIPPET hasn't been committed."
+  (catch 'live
+    (yas--snippet-map-markers (lambda (m)
+                                (if (markerp m) m
+                                  (throw 'live nil)))
+                              snippet)
+    t))
+
+(defun yas--apply-transform (field-or-mirror field &optional empty-on-nil-p)
+  "Calculate transformed string for FIELD-OR-MIRROR from FIELD.
+
+If there is no transform for ht field, return nil.
+
+If there is a transform but it returns nil, return the empty
+string iff EMPTY-ON-NIL-P is true."
+  (let* ((yas-text (yas--field-text-for-display field))
+         (yas-modified-p (yas--field-modified-p field))
+         (transform (if (yas--mirror-p field-or-mirror)
+                        (yas--mirror-transform field-or-mirror)
+                      (yas--field-transform field-or-mirror)))
+         (start-point (if (yas--mirror-p field-or-mirror)
+                          (yas--mirror-start field-or-mirror)
+                        (yas--field-start field-or-mirror)))
+         (transformed (and transform
+                           (save-excursion
+                             (goto-char start-point)
+                             (let ((ret (yas--eval-for-string transform)))
+                               (or ret (and empty-on-nil-p "")))))))
+    transformed))
+
+(defsubst yas--replace-all (from to &optional text)
+  "Replace all occurrences from FROM to TO.
+
+With optional string TEXT do it in that string."
+  (if text
+      (replace-regexp-in-string (regexp-quote from) to text t t)
+    (goto-char (point-min))
+    (while (search-forward from nil t)
+      (replace-match to t t text))))
+
+(defun yas--snippet-find-field (snippet number)
+  (cl-find-if (lambda (field)
+                (eq number (yas--field-number field)))
+              (yas--snippet-fields snippet)))
+
+(defun yas--snippet-sort-fields (snippet)
+  "Sort the fields of SNIPPET in navigation order."
+  (setf (yas--snippet-fields snippet)
+        (sort (yas--snippet-fields snippet)
+              #'yas--snippet-field-compare)))
+
+(defun yas--snippet-field-compare (field1 field2)
+  "Compare FIELD1 and FIELD2.
+
+The field with a number is sorted first.  If they both have a
+number, compare through the number.  If neither have, compare
+through the field's start point"
+  (let ((n1 (yas--field-number field1))
+        (n2 (yas--field-number field2)))
+    (if n1
+        (if n2
+            (or (zerop n2) (and (not (zerop n1))
+                                (< n1 n2)))
+          (not (zerop n1)))
+      (if n2
+          (zerop n2)
+        (< (yas--field-start field1)
+           (yas--field-start field2))))))
+
+(defun yas--field-probably-deleted-p (snippet field)
+  "Guess if SNIPPET's FIELD should be skipped."
+  (and
+   ;; field must be zero length
+   ;;
+   (zerop (- (yas--field-start field) (yas--field-end field)))
+   ;; field must have been modified
+   ;;
+   (yas--field-modified-p field)
+   ;; either:
+   (or
+    ;;  1) it's a nested field
+    ;;
+    (yas--field-parent-field field)
+    ;;  2) ends just before the snippet end
+    ;;
+    (and (eq field (car (last (yas--snippet-fields snippet))))
+         (= (yas--field-start field) (overlay-end (yas--snippet-control-overlay snippet)))))
+   ;; the field numbered 0, just before the exit marker, should
+   ;; never be skipped
+   ;;
+   (not (and (yas--field-number field)
+             (zerop (yas--field-number field))))))
+
+(defun yas-active-snippets (&optional beg end)
+  "Return a sorted list of active snippets.
+The most recently-inserted snippets are returned first.
+
+Only snippets overlapping the region BEG ... END are returned.
+Overlapping has the same meaning as described in `overlays-in'.
+If END is omitted, it defaults to (1+ BEG).  If BEG is omitted,
+it defaults to point.  A non-nil, non-buffer position BEG is
+equivalent to a range covering the whole buffer."
+  (unless beg
+    (setq beg (point)))
+  (cond ((not (or (integerp beg) (markerp beg)))
+         (setq beg (point-min) end (point-max)))
+        ((not end)
+         (setq end (1+ beg))))
+  (if (and (eq beg (point-min))
+           (eq end (point-max)))
+      yas--active-snippets
+    ;; Note: don't use `mapcar' here, since it would allocate in
+    ;; proportion to the amount of overlays, even though the list of
+    ;; active snippets should be very small.
+    (let ((snippets nil))
+      (dolist (ov (overlays-in beg end))
+        (let ((snippet (overlay-get ov 'yas--snippet)))
+          ;; Snippets have multiple overlays, so check for dups.
+          (when (and snippet (not (memq snippet snippets)))
+            (push snippet snippets))))
+      (cl-sort snippets #'>= :key #'yas--snippet-id))))
+
+(define-obsolete-function-alias 'yas--snippets-at-point
+  'yas-active-snippets "0.12")
+
+(defun yas-next-field-or-maybe-expand ()
+  "Try to expand a snippet at a key before point.
+
+Otherwise delegate to `yas-next-field'."
+  (interactive)
+  (if yas-triggers-in-field
+      (let ((yas-fallback-behavior 'return-nil)
+            (active-field (overlay-get yas--active-field-overlay 'yas--field)))
+        (when active-field
+          (unless (yas-expand-from-trigger-key active-field)
+            (yas-next-field))))
+    (yas-next-field)))
+
+(defun yas-next-field-will-exit-p (&optional arg)
+  "Return non-nil if (yas-next-field ARG) would exit the current snippet."
+  (let ((snippet (car (yas-active-snippets)))
+        (active (overlay-get yas--active-field-overlay 'yas--field)))
+    (when snippet
+      (not (yas--find-next-field arg snippet active)))))
+
+(defun yas--find-next-field (n snippet active)
+  "Return the Nth field after the ACTIVE one in SNIPPET."
+  (let ((live-fields (cl-remove-if
+                      (lambda (field)
+                        (and (not (eq field active))
+                             (yas--field-probably-deleted-p snippet field)))
+                      (yas--snippet-fields snippet))))
+    (nth (abs n) (memq active (if (>= n 0) live-fields (reverse live-fields))))))
+
+(defun yas-next-field (&optional arg)
+  "Navigate to the ARGth next field.
+
+If there's none, exit the snippet."
+  (interactive)
+  (unless arg (setq arg 1))
+  (let* ((snippet (car (yas-active-snippets)))
+         (active-field (overlay-get yas--active-field-overlay 'yas--field))
+         (target-field (yas--find-next-field arg snippet active-field)))
+    (yas--letenv (yas--snippet-expand-env snippet)
+      ;; Apply transform to active field.
+      (when active-field
+        (let ((yas-moving-away-p t))
+          (when (yas--field-update-display active-field)
+            (yas--update-mirrors snippet))))
+      ;; Now actually move...
+      (if target-field
+          (yas--move-to-field snippet target-field)
+        (yas-exit-snippet snippet)))))
+
+(defun yas--place-overlays (snippet field)
+  "Correctly place overlays for SNIPPET's FIELD."
+  (yas--make-move-field-protection-overlays snippet field)
+  ;; Only move active field overlays if this is field is from the
+  ;; innermost snippet.
+  (when (eq snippet (car (yas-active-snippets (1- (yas--field-start field))
+                                              (1+ (yas--field-end field)))))
+    (yas--make-move-active-field-overlay snippet field)))
+
+(defun yas--move-to-field (snippet field)
+  "Update SNIPPET to move to field FIELD.
+
+Also create some protection overlays"
+  (goto-char (yas--field-start field))
+  (yas--place-overlays snippet field)
+  (overlay-put yas--active-field-overlay 'yas--snippet snippet)
+  (overlay-put yas--active-field-overlay 'yas--field field)
+  (let ((number (yas--field-number field)))
+    ;; check for the special ${0: ...} field
+    (if (and number (zerop number))
+        (progn
+          (set-mark (yas--field-end field))
+          (setf (yas--snippet-force-exit snippet)
+                (or (yas--field-transform field)
+                    t)))
+      ;; make this field active
+      (setf (yas--snippet-active-field snippet) field)
+      ;; primary field transform: first call to snippet transform
+      (unless (yas--field-modified-p field)
+        (if (yas--field-update-display field)
+            (yas--update-mirrors snippet)
+          (setf (yas--field-modified-p field) nil))))))
+
+(defun yas-prev-field ()
+  "Navigate to prev field.  If there's none, exit the snippet."
+  (interactive)
+  (yas-next-field -1))
+
+(defun yas-abort-snippet (&optional snippet)
+  (interactive)
+  (let ((snippet (or snippet
+                     (car (yas-active-snippets)))))
+    (when snippet
+      (setf (yas--snippet-force-exit snippet) t))))
+
+(defun yas-exit-snippet (snippet)
+  "Goto exit-marker of SNIPPET."
+  (interactive (list (cl-first (yas-active-snippets))))
+  (when snippet
+    (setf (yas--snippet-force-exit snippet) t)
+    (goto-char (if (yas--snippet-exit snippet)
+                   (yas--exit-marker (yas--snippet-exit snippet))
+                 (overlay-end (yas--snippet-control-overlay snippet))))))
+
+(defun yas-exit-all-snippets ()
+  "Exit all snippets."
+  (interactive)
+  (mapc #'(lambda (snippet)
+            (yas-exit-snippet snippet)
+            (yas--check-commit-snippet))
+        (yas-active-snippets 'all)))
+
+
+;;; Some low level snippet-routines:
+
+(defvar yas--inhibit-overlay-hooks nil
+  "Bind this temporarily to non-nil to prevent running `yas--on-*-modification'.")
+
+(defvar yas-snippet-beg nil "Beginning position of the last snippet committed.")
+(defvar yas-snippet-end nil "End position of the last snippet committed.")
+
+(defun yas--commit-snippet (snippet)
+  "Commit SNIPPET, but leave point as it is.
+
+This renders the snippet as ordinary text."
+
+  (let ((control-overlay (yas--snippet-control-overlay snippet)))
+    ;;
+    ;; Save the end of the moribund snippet in case we need to revive it
+    ;; its original expansion.
+    ;;
+    (when (and control-overlay
+               (overlay-buffer control-overlay))
+      (setq yas-snippet-beg (overlay-start control-overlay))
+      (setq yas-snippet-end (overlay-end control-overlay))
+      (delete-overlay control-overlay)
+      (setf (yas--snippet-control-overlay snippet) nil))
+
+    (let ((yas--inhibit-overlay-hooks t))
+      (when yas--active-field-overlay
+        (delete-overlay yas--active-field-overlay))
+      (when yas--field-protection-overlays
+        (mapc #'delete-overlay yas--field-protection-overlays)))
+
+    ;; stacked expansion: if the original expansion took place from a
+    ;; field, make sure we advance it here at least to
+    ;; `yas-snippet-end'...
+    ;;
+    (let ((previous-field (yas--snippet-previous-active-field snippet)))
+      (when (and yas-snippet-end previous-field)
+        (yas--advance-end-maybe previous-field yas-snippet-end)))
+
+    ;; Convert all markers to points,
+    ;;
+    (yas--markers-to-points snippet)
+
+    ;; It's no longer an active snippet.
+    (cl-callf2 delq snippet yas--active-snippets)
+
+    ;; Take care of snippet revival on undo.
+    (if (and yas-snippet-revival (listp buffer-undo-list))
+        (push `(apply yas--snippet-revive ,yas-snippet-beg ,yas-snippet-end ,snippet)
+              buffer-undo-list)
+      ;; Dismember the snippet... this is useful if we get called
+      ;; again from `yas--take-care-of-redo'....
+      (setf (yas--snippet-fields snippet) nil)))
+
+  (yas--message 4 "Snippet %s exited." (yas--snippet-id snippet)))
+
+(defvar yas--snippets-to-move nil)
+(make-variable-buffer-local 'yas--snippets-to-move)
+
+(defun yas--prepare-snippets-for-move (beg end buf pos)
+  "Gather snippets in BEG..END for moving to POS in BUF."
+  (let ((to-move nil)
+        (snippets (yas-active-snippets beg end))
+        (dst-base-line (with-current-buffer buf
+                         (count-lines (point-min) pos))))
+    (when snippets
+      (dolist (snippet snippets)
+        (yas--snippet-map-markers
+         (lambda (m)
+           (goto-char m)
+           (beginning-of-line)
+           (prog1 (cons (count-lines (point-min) (point))
+                        (yas--snapshot-marker-location m))
+             (set-marker m nil)))
+         snippet)
+        (let ((ctrl-ov (yas--snapshot-overlay-line-location
+                        (yas--snippet-control-overlay snippet))))
+          (push (list ctrl-ov dst-base-line snippet) to-move)
+          (delete-overlay (car ctrl-ov))))
+      (with-current-buffer buf
+        (setq yas--snippets-to-move (nconc to-move yas--snippets-to-move))))))
+
+(defun yas--on-buffer-kill ()
+  ;; Org mode uses temp buffers for fontification and "native tab",
+  ;; move all the snippets to the original org-mode buffer when it's
+  ;; killed.
+  (let ((org-marker nil))
+    (when (and yas-minor-mode
+               (or (bound-and-true-p org-edit-src-from-org-mode)
+                   (bound-and-true-p org-src--from-org-mode))
+               (markerp
+                (setq org-marker
+                      (or (bound-and-true-p org-edit-src-beg-marker)
+                          (bound-and-true-p org-src--beg-marker)))))
+      (yas--prepare-snippets-for-move
+       (point-min) (point-max)
+       (marker-buffer org-marker) org-marker))))
+
+(add-hook 'kill-buffer-hook #'yas--on-buffer-kill)
+
+(defun yas--finish-moving-snippets ()
+  "Finish job started in `yas--prepare-snippets-for-move'."
+  (cl-loop for (ctrl-ov base-line snippet) in yas--snippets-to-move
+           for base-pos = (progn (goto-char (point-min))
+                                 (forward-line base-line) (point))
+           do (yas--snippet-map-markers
+               (lambda (l-m-r-w)
+                 (goto-char base-pos)
+                 (forward-line (nth 0 l-m-r-w))
+                 (save-restriction
+                   (narrow-to-region (line-beginning-position)
+                                     (line-end-position))
+                   (yas--restore-marker-location (cdr l-m-r-w)))
+                 (nth 1 l-m-r-w))
+               snippet)
+           (goto-char base-pos)
+           (yas--restore-overlay-location ctrl-ov)
+           (yas--maybe-move-to-active-field snippet))
+  (setq yas--snippets-to-move nil))
+
+(defun yas--safely-call-fun (fun)
+  "Call FUN and catch any errors."
+  (condition-case error
+      (funcall fun)
+    ((debug error)
+     (yas--message 2 "Error running %s: %s" fun
+                   (error-message-string error)))))
+
+(defun yas--safely-run-hook (hook)
+  "Call HOOK's functions.
+HOOK should be a symbol, a hook variable, as in `run-hooks'."
+  (let ((debug-on-error (and (not (memq yas-good-grace '(t hooks)))
+                             debug-on-error)))
+    (yas--safely-call-fun (apply-partially #'run-hooks hook))))
+
+(defun yas--check-commit-snippet ()
+  "Check if point exited the currently active field of the snippet.
+
+If so cleans up the whole snippet up."
+  (let* ((snippet-exit-transform nil)
+         (exited-snippets-p nil)
+         ;; Record the custom snippet `yas-after-exit-snippet-hook'
+         ;; set in the expand-env field.
+         (snippet-exit-hook yas-after-exit-snippet-hook))
+    (dolist (snippet yas--active-snippets)
+      (let ((active-field (yas--snippet-active-field snippet)))
+        (yas--letenv (yas--snippet-expand-env snippet)
+          ;; Note: the `force-exit' field could be a transform in case of
+          ;; ${0: ...}, see `yas--move-to-field'.
+          (setq snippet-exit-transform (yas--snippet-force-exit snippet))
+          (cond ((or snippet-exit-transform
+                     (not (and active-field (yas--field-contains-point-p active-field))))
+                 (setf (yas--snippet-force-exit snippet) nil)
+                 (setq snippet-exit-hook yas-after-exit-snippet-hook)
+                 (yas--commit-snippet snippet)
+                 (setq exited-snippets-p t))
+                ((and active-field
+                      (or (not yas--active-field-overlay)
+                          (not (overlay-buffer yas--active-field-overlay))))
+                 ;;
+                 ;; stacked expansion: this case is mainly for recent
+                 ;; snippet exits that place us back int the field of
+                 ;; another snippet
+                 ;;
+                 (save-excursion
+                   (yas--move-to-field snippet active-field)
+                   (yas--update-mirrors snippet)))
+                (t
+                 nil)))))
+    (unless (or yas--active-snippets (not exited-snippets-p))
+      (when snippet-exit-transform
+        (yas--eval-for-effect snippet-exit-transform))
+      (let ((yas-after-exit-snippet-hook snippet-exit-hook))
+        (yas--safely-run-hook 'yas-after-exit-snippet-hook)))))
+
+;; Apropos markers-to-points:
+;;
+;; This was found useful for performance reasons, so that an excessive
+;; number of live markers aren't kept around in the
+;; `buffer-undo-list'.  We don't reuse the original marker object
+;; because that leaves an unreadable object in the history list and
+;; undo-tree persistence has trouble with that.
+;;
+;; This shouldn't bring horrible problems with undo/redo, but you
+;; never know.
+;;
+(defun yas--markers-to-points (snippet)
+  "Save all markers of SNIPPET as positions."
+  (yas--snippet-map-markers (lambda (m)
+                              (prog1 (marker-position m)
+                                (set-marker m nil)))
+                            snippet))
+
+(defun yas--points-to-markers (snippet)
+  "Restore SNIPPET's marker positions, saved by `yas--markers-to-points'."
+  (yas--snippet-map-markers #'copy-marker snippet))
+
+(defun yas--maybe-move-to-active-field (snippet)
+  "Try to move to SNIPPET's active (or first) field and return it if found."
+  (let ((target-field (or (yas--snippet-active-field snippet)
+                          (car (yas--snippet-fields snippet)))))
+    (when target-field
+      (yas--move-to-field snippet target-field)
+      target-field)))
+
+(defun yas--field-contains-point-p (field &optional point)
+  (let ((point (or point
+                   (point))))
+    (and (>= point (yas--field-start field))
+         (<= point (yas--field-end field)))))
+
+(defun yas--field-text-for-display (field)
+  "Return the propertized display text for field FIELD."
+  (buffer-substring (yas--field-start field) (yas--field-end field)))
+
+(defun yas--undo-in-progress ()
+  "True if some kind of undo is in progress."
+  (or undo-in-progress
+      (eq this-command 'undo)
+      (eq this-command 'redo)))
+
+(defun yas--make-control-overlay (snippet start end)
+  "Create the control overlay that surrounds the snippet and
+holds the keymap."
+  (let ((overlay (make-overlay start
+                               end
+                               nil
+                               nil
+                               t)))
+    (overlay-put overlay 'keymap yas-keymap)
+    (overlay-put overlay 'priority yas-overlay-priority)
+    (overlay-put overlay 'yas--snippet snippet)
+    overlay))
+
+(defun yas-current-field ()
+  "Return the currently active field."
+  (and yas--active-field-overlay
+       (overlay-buffer yas--active-field-overlay)
+       (overlay-get yas--active-field-overlay 'yas--field)))
+
+(defun yas--maybe-clear-field-filter (cmd)
+  "Return CMD if at start of unmodified snippet field.
+Use as a `:filter' argument for a conditional keybinding."
+  (let ((field (yas-current-field)))
+    (when (and field
+               (not (yas--field-modified-p field))
+               (eq (point) (marker-position (yas--field-start field))))
+      cmd)))
+
+(defun yas-skip-and-clear-field (&optional field)
+  "Clears unmodified FIELD if at field start, skips to next tab."
+  (interactive)
+  (yas--skip-and-clear (or field (yas-current-field)))
+  (yas-next-field 1))
+
+(defun yas-skip-and-clear-or-delete-char (&optional field)
+  "Clears unmodified field if at field start, skips to next tab.
+
+Otherwise deletes a character normally by calling `delete-char'."
+  (interactive)
+  (declare (obsolete "Bind to `yas-maybe-skip-and-clear-field' instead." "0.13"))
+  (cond ((yas--maybe-clear-field-filter t)
+         (yas--skip-and-clear (or field (yas-current-field)))
+         (yas-next-field 1))
+        (t (call-interactively 'delete-char))))
+
+(defun yas--skip-and-clear (field &optional from)
+  "Deletes the region of FIELD and sets it's modified state to t.
+If given, FROM indicates position to start at instead of FIELD's beginning."
+  ;; Just before skipping-and-clearing the field, mark its children
+  ;; fields as modified, too. If the children have mirrors-in-fields
+  ;; this prevents them from updating erroneously (we're skipping and
+  ;; deleting!).
+  ;;
+  (yas--mark-this-and-children-modified field)
+  (unless (= (yas--field-start field) (yas--field-end field))
+    (delete-region (or from (yas--field-start field)) (yas--field-end field))))
+
+(defun yas--mark-this-and-children-modified (field)
+  (setf (yas--field-modified-p field) t)
+  (let ((fom (yas--field-next field)))
+    (while (and fom
+                (yas--fom-parent-field fom))
+      (when (and (eq (yas--fom-parent-field fom) field)
+                 (yas--field-p fom))
+        (yas--mark-this-and-children-modified fom))
+      (setq fom (yas--fom-next fom)))))
+
+(defun yas--make-move-active-field-overlay (snippet field)
+  "Place the active field overlay in SNIPPET's FIELD.
+
+Move the overlay, or create it if it does not exit."
+  (if (and yas--active-field-overlay
+           (overlay-buffer yas--active-field-overlay))
+      (move-overlay yas--active-field-overlay
+                    (yas--field-start field)
+                    (yas--field-end field))
+    (setq yas--active-field-overlay
+          (make-overlay (yas--field-start field)
+                        (yas--field-end field)
+                        nil nil t))
+    (overlay-put yas--active-field-overlay 'priority yas-overlay-priority)
+    (overlay-put yas--active-field-overlay 'face 'yas-field-highlight-face)
+    (overlay-put yas--active-field-overlay 'yas--snippet snippet)
+    (overlay-put yas--active-field-overlay 'modification-hooks '(yas--on-field-overlay-modification))
+    (overlay-put yas--active-field-overlay 'insert-in-front-hooks
+                 '(yas--on-field-overlay-modification))
+    (overlay-put yas--active-field-overlay 'insert-behind-hooks
+                 '(yas--on-field-overlay-modification))))
+
+(defun yas--skip-and-clear-field-p (field beg _end length)
+  "Tell if newly modified FIELD should be cleared and skipped.
+BEG, END and LENGTH like overlay modification hooks."
+  (and (= length 0) ; A 0 pre-change length indicates insertion.
+       (= beg (yas--field-start field)) ; Insertion at field start?
+       (not (yas--field-modified-p field))))
+
+(defun yas--on-field-overlay-modification (overlay after? beg end &optional length)
+  "Clears the field and updates mirrors, conditionally.
+
+Only clears the field if it hasn't been modified and point is at
+field start.  This hook does nothing if an undo is in progress."
+  (unless (or (not after?)
+              yas--inhibit-overlay-hooks
+              (not (overlayp yas--active-field-overlay)) ; Avoid Emacs bug #21824.
+              ;; If a single change hits multiple overlays of the same
+              ;; snippet, then we delete the snippet the first time,
+              ;; and then subsequent calls get a deleted overlay.
+              ;; Don't delete the snippet again!
+              (not (overlay-buffer overlay))
+              (yas--undo-in-progress))
+    (let* ((inhibit-modification-hooks nil)
+           (yas--inhibit-overlay-hooks t)
+           (field (overlay-get overlay 'yas--field))
+           (snippet (overlay-get yas--active-field-overlay 'yas--snippet)))
+      (if (yas--snippet-live-p snippet)
+          (save-match-data
+            (yas--letenv (yas--snippet-expand-env snippet)
+              (when (yas--skip-and-clear-field-p field beg end length)
+                ;; We delete text starting from the END of insertion.
+                (yas--skip-and-clear field end))
+              (setf (yas--field-modified-p field) t)
+              (yas--advance-end-maybe field (overlay-end overlay))
+              (save-excursion
+                (yas--field-update-display field))
+              (yas--update-mirrors snippet)))
+        (lwarn '(yasnippet zombie) :warning "Killing zombie snippet!")
+        (delete-overlay overlay)))))
+
+(defun yas--auto-fill ()
+  (let* ((orig-point (point))
+         (end (progn (forward-paragraph) (point)))
+         (beg (progn (backward-paragraph) (point)))
+         (snippets (yas-active-snippets beg end))
+         (remarkers nil)
+         (reoverlays nil))
+    (dolist (snippet snippets)
+      (dolist (m (yas--collect-snippet-markers snippet))
+        (when (and (<= beg m) (<= m end))
+          (push (yas--snapshot-marker-location m beg end) remarkers)))
+      (push (yas--snapshot-overlay-location
+             (yas--snippet-control-overlay snippet) beg end)
+            reoverlays))
+    (goto-char orig-point)
+    (let ((yas--inhibit-overlay-hooks t))
+      (if (null yas--original-auto-fill-function)
+          ;; Try to get more info on #873/919.
+          (let ((yas--fill-fun-values `((t ,(default-value 'yas--original-auto-fill-function))))
+                (fill-fun-values `((t ,(default-value 'auto-fill-function))))
+                ;; Listing 2 buffers with the same value is enough
+                (print-length 3))
+            (save-current-buffer
+              (dolist (buf (let ((bufs (buffer-list)))
+                             ;; List the current buffer first.
+                             (setq bufs (cons (current-buffer)
+                                              (remq (current-buffer) bufs)))))
+                (set-buffer buf)
+                (let* ((yf-cell (assq yas--original-auto-fill-function
+                                      yas--fill-fun-values))
+                       (af-cell (assq auto-fill-function fill-fun-values)))
+                  (when (local-variable-p 'yas--original-auto-fill-function)
+                    (if yf-cell (setcdr yf-cell (cons buf (cdr yf-cell)))
+                      (push (list yas--original-auto-fill-function buf) yas--fill-fun-values)))
+                  (when (local-variable-p 'auto-fill-function)
+                    (if af-cell (setcdr af-cell (cons buf (cdr af-cell)))
+                      (push (list auto-fill-function buf) fill-fun-values))))))
+                 (lwarn '(yasnippet auto-fill bug) :error
+                        "`yas--original-auto-fill-function' unexpectedly nil in %S!  Disabling auto-fill.
+  %S
+  `auto-fill-function': %S\n%s"
+                        (current-buffer) yas--fill-fun-values fill-fun-values
+                        (if (fboundp 'backtrace--print-frame)
+                            (with-output-to-string
+                              (mapc (lambda (frame)
+                                      (apply #'backtrace--print-frame frame))
+                                    yas--watch-auto-fill-backtrace))
+                          ""))
+                 ;; Try to avoid repeated triggering of this bug.
+                 (auto-fill-mode -1)
+                 ;; Don't pop up more than once in a session (still log though).
+                 (defvar warning-suppress-types) ; `warnings' is autoloaded by `lwarn'.
+                 (add-to-list 'warning-suppress-types '(yasnippet auto-fill bug)))
+        (funcall yas--original-auto-fill-function)))
+    (save-excursion
+      (setq end (progn (forward-paragraph) (point)))
+      (setq beg (progn (backward-paragraph) (point))))
+    (save-excursion
+      (save-restriction
+        (narrow-to-region beg end)
+        (mapc #'yas--restore-marker-location remarkers)
+        (mapc #'yas--restore-overlay-location reoverlays))
+      (mapc (lambda (snippet)
+              (yas--letenv (yas--snippet-expand-env snippet)
+                (yas--update-mirrors snippet)))
+            snippets))))
+
+
+;;; Apropos protection overlays:
+;;
+;; These exist for nasty users who will try to delete parts of the
+;; snippet outside the active field. Actual protection happens in
+;; `yas--on-protection-overlay-modification'.
+;;
+;; As of github #537 this no longer inhibits the command by issuing an
+;; error: all the snippets at point, including nested snippets, are
+;; automatically commited and the current command can proceed.
+;;
+(defun yas--make-move-field-protection-overlays (snippet field)
+  "Place protection overlays surrounding SNIPPET's FIELD.
+
+Move the overlays, or create them if they do not exit."
+  (let ((start (yas--field-start field))
+        (end (yas--field-end field)))
+    ;; First check if the (1+ end) is contained in the buffer,
+    ;; otherwise we'll have to do a bit of cheating and silently
+    ;; insert a newline. the `(1+ (buffer-size))' should prevent this
+    ;; when using stacked expansion
+    ;;
+    (when (< (buffer-size) end)
+      (save-excursion
+        (let ((yas--inhibit-overlay-hooks t))
+          (goto-char (point-max))
+          (newline))))
+    ;; go on to normal overlay creation/moving
+    ;;
+    (cond ((and yas--field-protection-overlays
+                (cl-every #'overlay-buffer yas--field-protection-overlays))
+           (move-overlay (nth 0 yas--field-protection-overlays)
+                         (1- start) start)
+           (move-overlay (nth 1 yas--field-protection-overlays) end (1+ end)))
+          (t
+           (setq yas--field-protection-overlays
+                 (list (make-overlay (1- start) start nil t nil)
+                       (make-overlay end (1+ end) nil t nil)))
+           (dolist (ov yas--field-protection-overlays)
+             (overlay-put ov 'face 'yas--field-debug-face)
+             (overlay-put ov 'yas--snippet snippet)
+             ;; (overlay-put ov 'evaporate t)
+             (overlay-put ov 'modification-hooks '(yas--on-protection-overlay-modification)))))))
+
+(defun yas--on-protection-overlay-modification (_overlay after? beg end &optional length)
+  "Commit the snippet if the protection overlay is being killed."
+  (unless (or yas--inhibit-overlay-hooks
+              (not after?)
+              (= length (- end beg)) ; deletion or insertion
+              (yas--undo-in-progress))
+    (let ((snippets (yas-active-snippets)))
+      (yas--message 2 "Committing snippets. Action would destroy a protection overlay.")
+      (cl-loop for snippet in snippets
+               do (yas--commit-snippet snippet)))))
+
+(add-to-list 'debug-ignored-errors "^Exit the snippet first!$")
+
+
+;;; Snippet expansion and "stacked" expansion:
+;;
+;; Stacked expansion is when you try to expand a snippet when already
+;; inside a snippet expansion.
+;;
+;; The parent snippet does not run its fields modification hooks
+;; (`yas--on-field-overlay-modification' and
+;; `yas--on-protection-overlay-modification') while the child snippet
+;; is active. This means, among other things, that the mirrors of the
+;; parent snippet are not updated, this only happening when one exits
+;; the child snippet.
+;;
+;; Unfortunately, this also puts some ugly (and not fully-tested)
+;; bits of code in `yas-expand-snippet' and
+;; `yas--commit-snippet'. I've tried to mark them with "stacked
+;; expansion:".
+;;
+;; This was thought to be safer in an undo/redo perspective, but
+;; maybe the correct implementation is to make the globals
+;; `yas--active-field-overlay' and `yas--field-protection-overlays' be
+;; snippet-local and be active even while the child snippet is
+;; running. This would mean a lot of overlay modification hooks
+;; running, but if managed correctly (including overlay priorities)
+;; they should account for all situations...
+
+(defun yas-expand-snippet (snippet &optional start end expand-env)
+  "Expand SNIPPET at current point.
+
+Text between START and END will be deleted before inserting
+template.  EXPAND-ENV is a list of (SYM VALUE) let-style dynamic
+bindings considered when expanding the snippet.  If omitted, use
+SNIPPET's expand-env field.
+
+SNIPPET may be a snippet structure (e.g., as returned by
+`yas-lookup-snippet'), or just a snippet body (which is a string
+for normal snippets, and a list for command snippets)."
+  (cl-assert (and yas-minor-mode
+                  (memq 'yas--post-command-handler post-command-hook))
+             nil
+             "[yas] `yas-expand-snippet' needs properly setup `yas-minor-mode'")
+  (run-hooks 'yas-before-expand-snippet-hook)
+
+  (let* ((clear-field
+          (let ((field (and yas--active-field-overlay
+                            (overlay-buffer yas--active-field-overlay)
+                            (overlay-get yas--active-field-overlay 'yas--field))))
+            (and field (yas--skip-and-clear-field-p
+                        field (point) (point) 0)
+                 field)))
+         (start (cond (start)
+                      ((region-active-p)
+                       (region-beginning))
+                      (clear-field
+                       (yas--field-start clear-field))
+                      (t (point))))
+         (end (cond (end)
+                    ((region-active-p)
+                     (region-end))
+                    (clear-field
+                     (yas--field-end clear-field))
+                    (t (point))))
+         (to-delete (and (> end start)
+                         (buffer-substring-no-properties start end)))
+         (yas-selected-text
+          (cond (yas-selected-text)
+                ((and (region-active-p)
+                      (not clear-field))
+                 to-delete))))
+    (goto-char start)
+    (setq yas--indent-original-column (current-column))
+    ;; Delete the region to delete, this *does* get undo-recorded.
+    (when to-delete
+      (delete-region start end))
+
+    (let ((content (if (yas--template-p snippet)
+                       (yas--template-content snippet)
+                     snippet)))
+      (when (and (not expand-env) (yas--template-p snippet))
+        (setq expand-env (yas--template-expand-env snippet)))
+      (cond ((listp content)
+             ;; x) This is a snippet-command.
+             (yas--eval-for-effect content))
+            (t
+             ;; x) This is a snippet-snippet :-)
+             (setq yas--start-column (current-column))
+             ;; Stacked expansion: also shoosh the overlay modification hooks.
+             (let ((yas--inhibit-overlay-hooks t))
+               (setq snippet
+                     (yas--snippet-create content expand-env start (point))))
+
+             ;; Stacked-expansion: This checks for stacked expansion, save the
+             ;; `yas--previous-active-field' and advance its boundary.
+             (let ((existing-field (and yas--active-field-overlay
+                                        (overlay-buffer yas--active-field-overlay)
+                                        (overlay-get yas--active-field-overlay 'yas--field))))
+               (when existing-field
+                 (setf (yas--snippet-previous-active-field snippet) existing-field)
+                 (yas--advance-end-maybe existing-field (overlay-end yas--active-field-overlay))))
+
+             ;; Exit the snippet immediately if no fields.
+             (unless (yas--snippet-fields snippet)
+               (yas-exit-snippet snippet))
+
+             ;; Now, schedule a move to the first field.
+             (let ((first-field (car (yas--snippet-fields snippet))))
+               (when first-field
+                 (sit-for 0) ;; fix issue 125
+                 (yas--letenv (yas--snippet-expand-env snippet)
+                   (yas--move-to-field snippet first-field))
+                 (when (and (eq (yas--field-number first-field) 0)
+                            (> (length (yas--field-text-for-display
+                                        first-field))
+                               0))
+                   ;; Keep region for ${0:exit text}.
+                   (setq deactivate-mark nil))))
+             (yas--message 4 "snippet %d expanded." (yas--snippet-id snippet))
+             t)))))
+
+(defun yas--take-care-of-redo (snippet)
+  "Commits SNIPPET, which in turn pushes an undo action for reviving it.
+
+Meant to exit in the `buffer-undo-list'."
+  ;; slightly optimize: this action is only needed for snippets with
+  ;; at least one field
+  (when (yas--snippet-fields snippet)
+    (yas--commit-snippet snippet)))
+
+(defun yas--snippet-revive (beg end snippet)
+  "Revives SNIPPET and creates a control overlay from BEG to END.
+
+BEG and END are, we hope, the original snippets boundaries.
+All the markers/points exiting existing inside SNIPPET should point
+to their correct locations *at the time the snippet is revived*.
+
+After revival, push the `yas--take-care-of-redo' in the
+`buffer-undo-list'"
+  ;; Reconvert all the points to markers
+  (yas--points-to-markers snippet)
+  ;; When at least one editable field existed in the zombie snippet,
+  ;; try to revive the whole thing...
+  (when (yas--maybe-move-to-active-field snippet)
+    (setf (yas--snippet-control-overlay snippet) (yas--make-control-overlay snippet beg end))
+    (overlay-put (yas--snippet-control-overlay snippet) 'yas--snippet snippet)
+    (when (listp buffer-undo-list)
+      (push `(apply yas--take-care-of-redo ,snippet)
+            buffer-undo-list))))
+
+(defun yas--snippet-create (content expand-env begin end)
+  "Create a snippet from a template inserted at BEGIN to END.
+
+Returns the newly created snippet."
+  (save-restriction
+    (let ((snippet (yas--make-snippet expand-env)))
+      (yas--letenv expand-env
+        ;; Put a single undo action for the expanded snippet's
+        ;; content.
+        (let ((buffer-undo-list t))
+          ;; Some versions of cc-mode fail when inserting snippet
+          ;; content in a narrowed buffer.
+          (goto-char begin)
+          (insert content)
+          (setq end (+ end (length content)))
+          (narrow-to-region begin end)
+          (goto-char (point-min))
+          (yas--snippet-parse-create snippet))
+        (when (listp buffer-undo-list)
+          (push (cons (point-min) (point-max))
+                buffer-undo-list))
+
+        ;; Indent, collecting undo information normally.
+        (yas--indent snippet)
+
+        ;; Follow up with `yas--take-care-of-redo' on the newly
+        ;; inserted snippet boundaries.
+        (when (listp buffer-undo-list)
+          (push `(apply yas--take-care-of-redo ,snippet)
+                buffer-undo-list))
+
+        ;; Sort and link each field
+        (yas--snippet-sort-fields snippet)
+
+        ;; Create keymap overlay for snippet
+        (setf (yas--snippet-control-overlay snippet)
+              (yas--make-control-overlay snippet (point-min) (point-max)))
+
+        ;; Move to end
+        (goto-char (point-max))
+
+        (push snippet yas--active-snippets)
+        snippet))))
+
+
+;;; Apropos adjacencies and "fom's":
+;;
+;; Once the $-constructs bits like "$n" and "${:n" are deleted in the
+;; recently expanded snippet, we might actually have many fields,
+;; mirrors (and the snippet exit) in the very same position in the
+;; buffer. Therefore we need to single-link the
+;; fields-or-mirrors-or-exit (which I have abbreviated to "fom")
+;; according to their original positions in the buffer.
+;;
+;; Then we have operation `yas--advance-end-maybe' and
+;; `yas--advance-start-maybe', which conditionally push the starts and
+;; ends of these foms down the chain.
+;;
+;; This allows for like the printf with the magic ",":
+;;
+;;   printf ("${1:%s}\\n"${1:$(if (string-match "%" text) "," "\);")}  \
+;;   $2${1:$(if (string-match "%" text) "\);" "")}$0
+;;
+(defun yas--fom-start (fom)
+  (cond ((yas--field-p fom)
+         (yas--field-start fom))
+        ((yas--mirror-p fom)
+         (yas--mirror-start fom))
+        (t
+         (yas--exit-marker fom))))
+
+(defun yas--fom-end (fom)
+  (cond ((yas--field-p fom)
+         (yas--field-end fom))
+        ((yas--mirror-p fom)
+         (yas--mirror-end fom))
+        (t
+         (yas--exit-marker fom))))
+
+(defun yas--fom-next (fom)
+  (cond ((yas--field-p fom)
+         (yas--field-next fom))
+        ((yas--mirror-p fom)
+         (yas--mirror-next fom))
+        (t
+         (yas--exit-next fom))))
+
+(defun yas--fom-parent-field (fom)
+  (cond ((yas--field-p fom)
+         (yas--field-parent-field fom))
+        ((yas--mirror-p fom)
+         (yas--mirror-parent-field fom))
+        (t
+         nil)))
+
+(defun yas--calculate-adjacencies (snippet)
+  "Calculate adjacencies for fields or mirrors of SNIPPET.
+
+This is according to their relative positions in the buffer, and
+has to be called before the $-constructs are deleted."
+  (let* ((fom-set-next-fom
+         (lambda (fom nextfom)
+           (cond ((yas--field-p fom)
+                  (setf (yas--field-next fom) nextfom))
+                 ((yas--mirror-p fom)
+                  (setf (yas--mirror-next fom) nextfom))
+                 (t
+                  (setf (yas--exit-next fom) nextfom)))))
+        (compare-fom-begs
+         (lambda (fom1 fom2)
+           (if (= (yas--fom-start fom2) (yas--fom-start fom1))
+               (yas--mirror-p fom2)
+             (>= (yas--fom-start fom2) (yas--fom-start fom1)))))
+        (link-foms fom-set-next-fom))
+    ;; make some yas--field, yas--mirror and yas--exit soup
+    (let ((soup))
+      (when (yas--snippet-exit snippet)
+        (push (yas--snippet-exit snippet) soup))
+      (dolist (field (yas--snippet-fields snippet))
+        (push field soup)
+        (dolist (mirror (yas--field-mirrors field))
+          (push mirror soup)))
+      (setq soup
+            (sort soup compare-fom-begs))
+      (when soup
+        (cl-reduce link-foms soup)))))
+
+(defun yas--calculate-simple-fom-parentage (snippet fom)
+  "Discover if FOM is parented by some field in SNIPPET.
+
+Use the tightest containing field if more than one field contains
+the mirror.  Intended to be called *before* the dollar-regions are
+deleted."
+  (let ((min (point-min))
+        (max (point-max)))
+    (dolist (field (remq fom (yas--snippet-fields snippet)))
+      (when (and (<= (yas--field-start field) (yas--fom-start fom))
+                 (<= (yas--fom-end fom) (yas--field-end field))
+               (< min (yas--field-start field))
+               (< (yas--field-end field) max))
+          (setq min (yas--field-start field)
+                max (yas--field-end field))
+          (cond ((yas--field-p fom)
+                 (setf (yas--field-parent-field fom) field))
+                ((yas--mirror-p fom)
+                 (setf (yas--mirror-parent-field fom) field))
+                (t ; it's an exit, so noop
+                 nil ))))))
+
+(defun yas--advance-end-maybe (fom newend)
+  "Maybe advance FOM's end to NEWEND if it needs it.
+
+If it does, also:
+
+* call `yas--advance-start-maybe' on FOM's next fom.
+
+* in case FOM is field call `yas--advance-end-maybe' on its parent
+  field
+
+Also, if FOM is an exit-marker, always call
+`yas--advance-start-maybe' on its next fom.  This is because
+exit-marker have identical start and end markers."
+  (cond ((and fom (< (yas--fom-end fom) newend))
+         (set-marker (yas--fom-end fom) newend)
+         (yas--advance-start-maybe (yas--fom-next fom) newend)
+         (yas--advance-end-of-parents-maybe (yas--fom-parent-field fom) newend))
+        ((yas--exit-p fom)
+         (yas--advance-start-maybe (yas--fom-next fom) newend))))
+
+(defun yas--advance-start-maybe (fom newstart)
+  "Maybe advance FOM's start to NEWSTART if it needs it.
+
+If it does, also call `yas--advance-end-maybe' on FOM."
+  (when (and fom (< (yas--fom-start fom) newstart))
+    (set-marker (yas--fom-start fom) newstart)
+    (yas--advance-end-maybe fom newstart)))
+
+(defun yas--advance-end-of-parents-maybe (field newend)
+  "Like `yas--advance-end-maybe' but for parent fields.
+
+Only works for fields and doesn't care about the start of the
+next FOM.  Works its way up recursively for parents of parents."
+  (when (and field
+             (< (yas--field-end field) newend))
+    (set-marker (yas--field-end field) newend)
+    (yas--advance-end-of-parents-maybe (yas--field-parent-field field) newend)))
+
+(defvar yas--dollar-regions nil
+  "When expanding the snippet the \"parse-create\" functions add
+cons cells to this var.")
+
+(defvar yas--indent-markers nil
+  "List of markers for manual indentation.")
+
+(defun yas--snippet-parse-create (snippet)
+  "Parse a recently inserted snippet template, creating all
+necessary fields, mirrors and exit points.
+
+Meant to be called in a narrowed buffer, does various passes"
+  (let ((saved-quotes nil)
+        (parse-start (point)))
+    ;; Avoid major-mode's syntax propertizing function, since we
+    ;; change the syntax-table while calling `scan-sexps'.
+    (let ((syntax-propertize-function nil))
+      (setq yas--dollar-regions nil)  ; Reset the yas--dollar-regions.
+      (yas--protect-escapes nil '(?`))  ; Protect just the backquotes.
+      (goto-char parse-start)
+      (setq saved-quotes (yas--save-backquotes)) ; `expressions`.
+      (yas--protect-escapes)            ; Protect escaped characters.
+      (goto-char parse-start)
+      (yas--indent-parse-create)        ; Parse indent markers: `$>'.
+      (goto-char parse-start)
+      (yas--field-parse-create snippet) ; Parse fields with {}.
+      (goto-char parse-start)
+      (yas--simple-fom-create snippet) ; Parse simple mirrors & fields.
+      (goto-char parse-start)
+      (yas--transform-mirror-parse-create snippet) ; Parse mirror transforms.
+      ;; Invalidate any syntax-propertizing done while
+      ;; `syntax-propertize-function' was nil.
+      (syntax-ppss-flush-cache parse-start))
+    ;; Set "next" links of fields & mirrors.
+    (yas--calculate-adjacencies snippet)
+    (yas--save-restriction-and-widen    ; Delete $-constructs.
+      (yas--delete-regions yas--dollar-regions))
+    ;; Make sure to do this insertion *after* deleting the dollar
+    ;; regions, otherwise we invalidate the calculated positions of
+    ;; all the fields following $0.
+    (let ((exit (yas--snippet-exit snippet)))
+      (goto-char (if exit (yas--exit-marker exit) (point-max))))
+    (when (eq yas-wrap-around-region 'cua)
+      (setq yas-wrap-around-region ?0))
+    (cond ((and yas-wrap-around-region yas-selected-text)
+           (insert yas-selected-text))
+          ((and (characterp yas-wrap-around-region)
+                (get-register yas-wrap-around-region))
+           (insert (prog1 (get-register yas-wrap-around-region)
+                     (set-register yas-wrap-around-region nil)))))
+    (yas--restore-backquotes saved-quotes)  ; Restore `expression` values.
+    (goto-char parse-start)
+    (yas--restore-escapes)        ; Restore escapes.
+    (yas--update-mirrors snippet) ; Update mirrors for the first time.
+    (goto-char parse-start)))
+
+;; HACK: Some implementations of `indent-line-function' (called via
+;; `indent-according-to-mode') delete text before they insert (like
+;; cc-mode), some make complicated regexp replacements (looking at
+;; you, org-mode).  To find place where the marker "should" go after
+;; indentation, we create a regexp based on what the line looks like
+;; before, putting a capture group where the marker is.  The regexp
+;; matches any whitespace with [[:space:]]* to allow for the
+;; indentation changing whitespace.  Additionally, we try to preserve
+;; the amount of whitespace *following* the marker, because
+;; indentation generally affects whitespace at the beginning, not the
+;; end.
+;;
+;; Two other cases where we apply a similar strategy:
+;;
+;; 1. Handling `auto-fill-mode', in this case we need to use the
+;; current paragraph instead of line.
+;;
+;; 2. Moving snippets from an `org-src' temp buffer into the main org
+;; buffer, in this case we need to count the line offsets (because org
+;; may add indentation on each line making character positions
+;; unreliable).
+;;
+;; This is all best-effort heuristic stuff, but it should cover 99% of
+;; use-cases.
+
+(defun yas--snapshot-marker-location (marker &optional beg end)
+  "Returns info for restoring MARKER's location after indent.
+The returned value is a list of the form (MARKER REGEXP WS-COUNT)."
+  (unless beg (setq beg (line-beginning-position)))
+  (unless end (setq end (line-end-position)))
+  (let ((before (split-string (buffer-substring-no-properties beg marker)
+                              "[[:space:]\n]+" t))
+        (after (split-string (buffer-substring-no-properties marker end)
+                             "[[:space:]\n]+" t)))
+    (list marker
+          (concat "[[:space:]\n]*"
+                  (mapconcat (lambda (s)
+                               (if (eq s marker) "\\(\\)"
+                                 (regexp-quote s)))
+                             (nconc before (list marker) after)
+                             "[[:space:]\n]*"))
+          (progn (goto-char marker)
+                 (skip-chars-forward "[:space:]\n" end)
+                 (- (point) marker)))))
+
+(defun yas--snapshot-overlay-location (overlay beg end)
+  "Like `yas--snapshot-marker-location' for overlays.
+The returned format is (OVERLAY (RE WS) (RE WS)).  Either of
+the (RE WS) lists may be nil if the start or end, respectively,
+of the overlay is outside the range BEG .. END."
+  (let ((obeg (overlay-start overlay))
+        (oend (overlay-end overlay)))
+    (list overlay
+          (when (and (<= beg obeg) (< obeg end))
+            (cdr (yas--snapshot-marker-location obeg beg end)))
+          (when (and (<= beg oend) (< oend end))
+            (cdr (yas--snapshot-marker-location oend beg end))))))
+
+(defun yas--snapshot-overlay-line-location (overlay)
+  "Return info for restoring OVERLAY's line based location.
+The returned format is (OVERLAY (LINE RE WS) (LINE RE WS))."
+  (let ((loc-beg (progn (goto-char (overlay-start overlay))
+                        (yas--snapshot-marker-location (point))))
+        (loc-end (progn (goto-char (overlay-end overlay))
+                        (yas--snapshot-marker-location (point)))))
+    (setcar loc-beg (count-lines (point-min) (progn (goto-char (car loc-beg))
+                                                    (line-beginning-position))))
+    (setcar loc-end (count-lines (point-min) (progn (goto-char (car loc-end))
+                                                    (line-beginning-position))))
+    (list overlay loc-beg loc-end)))
+
+(defun yas--goto-saved-location (regexp ws-count)
+  "Move point to location saved by `yas--snapshot-marker-location'.
+Buffer must be narrowed to BEG..END used to create the snapshot info."
+  (goto-char (point-min))
+  (if (not (looking-at regexp))
+      (lwarn '(yasnippet re-marker) :warning
+             "Couldn't find: %S" regexp)
+    (goto-char (match-beginning 1))
+    (skip-chars-forward "[:space:]\n")
+    (skip-chars-backward "[:space:]\n" (- (point) ws-count))))
+
+(defun yas--restore-marker-location (re-marker)
+  "Restores marker based on info from `yas--snapshot-marker-location'.
+Buffer must be narrowed to BEG..END used to create the snapshot info."
+  (apply #'yas--goto-saved-location (cdr re-marker))
+  (set-marker (car re-marker) (point)))
+
+(defun yas--restore-overlay-location (ov-locations)
+  "Restores marker based on info from `yas--snapshot-marker-location'.
+Buffer must be narrowed to BEG..END used to create the snapshot info."
+  (cl-destructuring-bind (overlay loc-beg loc-end) ov-locations
+    (move-overlay overlay
+                  (if (not loc-beg) (overlay-start overlay)
+                    (apply #'yas--goto-saved-location loc-beg)
+                    (point))
+                  (if (not loc-end) (overlay-end overlay)
+                    (apply #'yas--goto-saved-location loc-end)
+                    (point)))))
+
+
+(defun yas--restore-overlay-line-location (ov-locations)
+  "Restores overlay based on info from `yas--snapshot-overlay-line-location'."
+  (save-restriction
+    (move-overlay (car ov-locations)
+                  (save-excursion
+                    (forward-line (car (nth 1 ov-locations)))
+                    (narrow-to-region (line-beginning-position) (line-end-position))
+                    (apply #'yas--goto-saved-location (cdr (nth 1 ov-locations)))
+                    (point))
+                  (save-excursion
+                    (forward-line (car (nth 2 ov-locations)))
+                    (narrow-to-region (line-beginning-position) (line-end-position))
+                    (apply #'yas--goto-saved-location (cdr (nth 2 ov-locations)))
+                    (point)))))
+
+(defun yas--indent-region (from to snippet)
+  "Indent the lines between FROM and TO with `indent-according-to-mode'.
+The SNIPPET's markers are preserved."
+  (save-excursion
+    (yas--save-restriction-and-widen
+      (let* ((snippet-markers (yas--collect-snippet-markers snippet))
+             (to (set-marker (make-marker) to)))
+        (goto-char from)
+        (cl-loop for bol = (line-beginning-position)
+                 for eol = (line-end-position)
+                 if (or yas-also-indent-empty-lines
+                        (/= bol eol))
+                 do
+                 ;; Indent each non-empty line.
+                 (let ((remarkers nil))
+                   (dolist (m snippet-markers)
+                     (when (and (<= bol m) (<= m eol))
+                       (push (yas--snapshot-marker-location m bol eol)
+                             remarkers)))
+                   (unwind-protect
+                       (progn (back-to-indentation)
+                              (indent-according-to-mode))
+                     (save-restriction
+                       (narrow-to-region bol (line-end-position))
+                       (mapc #'yas--restore-marker-location remarkers))))
+                 while (and (zerop (forward-line 1))
+                            (< (point) to)))))))
+
+(defvar yas--indent-original-column nil)
+(defun yas--indent (snippet)
+  ;; Indent lines that had indent markers (`$>') on them.
+  (save-excursion
+    (dolist (marker yas--indent-markers)
+      (unless (eq yas-indent-line 'auto)
+        (goto-char marker)
+        (yas--indent-region (line-beginning-position)
+                            (line-end-position)
+                            snippet))
+      ;; Finished with this marker.
+      (set-marker marker nil))
+    (setq yas--indent-markers nil))
+  ;; Now do stuff for `fixed' and `auto'.
+  (save-excursion
+    ;; We need to be at end of line, so that `forward-line' will only
+    ;; report 0 if it actually moves over a newline.
+    (end-of-line)
+    (cond ((eq yas-indent-line 'fixed)
+           (when (= (forward-line 1) 0)
+             (let ((indent-line-function
+                    (lambda ()
+                      ;; We need to be at beginning of line in order to
+                      ;; indent existing whitespace correctly.
+                      (beginning-of-line)
+                      (indent-to-column yas--indent-original-column))))
+               (yas--indent-region (line-beginning-position)
+                                   (point-max)
+                                   snippet))))
+          ((eq yas-indent-line 'auto)
+           (when (or yas-also-auto-indent-first-line
+                     (= (forward-line 1) 0))
+             (yas--indent-region (line-beginning-position)
+                                 (point-max)
+                                 snippet))))))
+
+(defun yas--collect-snippet-markers (snippet)
+  "Make a list of all the markers used by SNIPPET."
+  (let (markers)
+    (yas--snippet-map-markers (lambda (m) (push m markers) m) snippet)
+    markers))
+
+(defun yas--escape-string (escaped)
+  (concat "YASESCAPE" (format "%d" escaped) "PROTECTGUARD"))
+
+(defun yas--protect-escapes (&optional text escaped)
+  "Protect all escaped characters with their numeric ASCII value.
+
+With optional string TEXT do it in string instead of buffer."
+  (let ((changed-text text)
+        (text-provided-p text))
+    (mapc #'(lambda (escaped)
+              (setq changed-text
+                    (yas--replace-all (concat "\\" (char-to-string escaped))
+                                     (yas--escape-string escaped)
+                                     (when text-provided-p changed-text))))
+          (or escaped yas--escaped-characters))
+    changed-text))
+
+(defun yas--restore-escapes (&optional text escaped)
+  "Restore all escaped characters from their numeric ASCII value.
+
+With optional string TEXT do it in string instead of the buffer."
+  (let ((changed-text text)
+        (text-provided-p text))
+    (mapc #'(lambda (escaped)
+              (setq changed-text
+                    (yas--replace-all (yas--escape-string escaped)
+                                     (char-to-string escaped)
+                                     (when text-provided-p changed-text))))
+          (or escaped yas--escaped-characters))
+    changed-text))
+
+(defun yas--save-backquotes ()
+  "Save all \"\\=`(lisp-expression)\\=`\"-style expressions.
+Return a list of (MARKER . STRING) entires for each backquoted
+Lisp expression."
+  (let* ((saved-quotes nil)
+         (yas--snippet-buffer (current-buffer))
+         (yas--change-detected nil)
+         (detect-change (lambda (_beg _end)
+                          (when (eq (current-buffer) yas--snippet-buffer)
+                            (setq yas--change-detected t)))))
+    (while (re-search-forward yas--backquote-lisp-expression-regexp nil t)
+      (let ((current-string (match-string-no-properties 1)) transformed)
+        (yas--save-restriction-and-widen
+          (delete-region (match-beginning 0) (match-end 0)))
+        (let ((before-change-functions
+               (cons detect-change before-change-functions)))
+          (setq transformed (yas--eval-for-string (yas--read-lisp
+                                                   (yas--restore-escapes
+                                                    current-string '(?`))))))
+        (goto-char (match-beginning 0))
+        (when transformed
+          (let ((marker (make-marker))
+                (before-change-functions (cdr before-change-functions)))
+            (yas--save-restriction-and-widen
+              (insert "Y") ;; quite horrendous, I love it :)
+              (set-marker marker (point))
+              (insert "Y"))
+            (push (cons marker transformed) saved-quotes)))))
+    (when yas--change-detected
+      (lwarn '(yasnippet backquote-change) :warning
+             "`%s' modified buffer in a backquote expression.
+  To hide this warning, add (yasnippet backquote-change) to `warning-suppress-types'."
+             (if yas--current-template
+                 (yas--template-name yas--current-template)
+               "Snippet")))
+    saved-quotes))
+
+(defun yas--restore-backquotes (saved-quotes)
+  "Replace markers in SAVED-QUOTES with their values.
+SAVED-QUOTES is the in format returned by `yas--save-backquotes'."
+  (cl-loop for (marker . string) in saved-quotes do
+           (save-excursion
+             (goto-char marker)
+             (yas--save-restriction-and-widen
+               (delete-char -1)
+               (insert string)
+               (delete-char 1))
+             (set-marker marker nil))))
+
+(defun yas--scan-sexps (from count)
+  (ignore-errors
+    (save-match-data ; `scan-sexps' may modify match data.
+      (with-syntax-table (standard-syntax-table)
+        (let ((parse-sexp-lookup-properties nil))
+          (scan-sexps from count))))))
+
+(defun yas--make-marker (pos)
+  "Create a marker at POS with nil `marker-insertion-type'."
+  (let ((marker (set-marker (make-marker) pos)))
+    (set-marker-insertion-type marker nil)
+    marker))
+
+(defun yas--indent-parse-create ()
+  "Parse the \"$>\" indentation markers just inserted."
+  (setq yas--indent-markers ())
+  (while (search-forward "$>" nil t)
+    (delete-region (match-beginning 0) (match-end 0))
+    ;; Mark the beginning of the line.
+    (push (yas--make-marker (line-beginning-position))
+          yas--indent-markers))
+  (setq yas--indent-markers (nreverse yas--indent-markers)))
+
+(defun yas--field-parse-create (snippet &optional parent-field)
+  "Parse most field expressions in SNIPPET, except for the simple one \"$n\".
+
+The following count as a field:
+
+* \"${n: text}\", for a numbered field with default text, as long as N is not 0;
+
+* \"${n: text$(expression)}, the same with a Lisp expression;
+  this is caught with the curiously named `yas--multi-dollar-lisp-expression-regexp'
+
+* the same as above but unnumbered, (no N:) and number is calculated automatically.
+
+When multiple expressions are found, only the last one counts."
+  ;;
+  (save-excursion
+    (while (re-search-forward yas--field-regexp nil t)
+      (let* ((real-match-end-0 (yas--scan-sexps (1+ (match-beginning 0)) 1))
+             (number (and (match-string-no-properties 1)
+                          (string-to-number (match-string-no-properties 1))))
+             (brand-new-field (and real-match-end-0
+                                   ;; break if on "$(" immediately
+                                   ;; after the ":", this will be
+                                   ;; caught as a mirror with
+                                   ;; transform later.
+                                   (not (string-match-p "\\`\\$[ \t\n]*("
+                                                        (match-string-no-properties 2)))
+                                   ;; allow ${0: some exit text}
+                                   ;; (not (and number (zerop number)))
+                                   (yas--make-field number
+                                                   (yas--make-marker (match-beginning 2))
+                                                   (yas--make-marker (1- real-match-end-0))
+                                                   parent-field))))
+        (when brand-new-field
+          (goto-char real-match-end-0)
+          (push (cons (1- real-match-end-0) real-match-end-0)
+                yas--dollar-regions)
+          (push (cons (match-beginning 0) (match-beginning 2))
+                yas--dollar-regions)
+          (push brand-new-field (yas--snippet-fields snippet))
+          (save-excursion
+            (save-restriction
+              (narrow-to-region (yas--field-start brand-new-field) (yas--field-end brand-new-field))
+              (goto-char (point-min))
+              (yas--field-parse-create snippet brand-new-field)))))))
+  ;; if we entered from a parent field, now search for the
+  ;; `yas--multi-dollar-lisp-expression-regexp'. This is used for
+  ;; primary field transformations
+  ;;
+  (when parent-field
+    (save-excursion
+      (while (re-search-forward yas--multi-dollar-lisp-expression-regexp nil t)
+        (let* ((real-match-end-1 (yas--scan-sexps (match-beginning 1) 1)))
+          ;; commit the primary field transformation if:
+          ;;
+          ;; 1. we don't find it in yas--dollar-regions (a subnested
+          ;; field) might have already caught it.
+          ;;
+          ;; 2. we really make sure we have either two '$' or some
+          ;; text and a '$' after the colon ':'. This is a FIXME: work
+          ;; my regular expressions and end these ugly hacks.
+          ;;
+          (when (and real-match-end-1
+                     (not (member (cons (match-beginning 0)
+                                        real-match-end-1)
+                                  yas--dollar-regions))
+                     (not (eq ?:
+                              (char-before (1- (match-beginning 1))))))
+            (let ((lisp-expression-string (buffer-substring-no-properties (match-beginning 1)
+                                                                          real-match-end-1)))
+              (setf (yas--field-transform parent-field)
+                    (yas--read-lisp (yas--restore-escapes lisp-expression-string))))
+            (push (cons (match-beginning 0) real-match-end-1)
+                  yas--dollar-regions)))))))
+
+(defun yas--transform-mirror-parse-create (snippet)
+  "Parse the \"${n:$(lisp-expression)}\" mirror transformations in SNIPPET."
+  (while (re-search-forward yas--transform-mirror-regexp nil t)
+    (let* ((real-match-end-0 (yas--scan-sexps (1+ (match-beginning 0)) 1))
+           (number (string-to-number (match-string-no-properties 1)))
+           (field (and number
+                       (not (zerop number))
+                       (yas--snippet-find-field snippet number)))
+           (brand-new-mirror
+            (and real-match-end-0
+                 field
+                 (yas--make-mirror (yas--make-marker (match-beginning 0))
+                                  (yas--make-marker (match-beginning 0))
+                                  (yas--read-lisp
+                                   (yas--restore-escapes
+                                    (buffer-substring-no-properties (match-beginning 2)
+                                                                    (1- real-match-end-0))))))))
+      (when brand-new-mirror
+        (push brand-new-mirror
+              (yas--field-mirrors field))
+        (yas--calculate-simple-fom-parentage snippet brand-new-mirror)
+        (push (cons (match-beginning 0) real-match-end-0) yas--dollar-regions)))))
+
+(defun yas--simple-fom-create (snippet)
+  "Parse the simple \"$n\" fields/mirrors/exitmarkers in SNIPPET."
+  (while (re-search-forward yas--simple-mirror-regexp nil t)
+    (let ((number (string-to-number (match-string-no-properties 1))))
+      (cond ((zerop number)
+             (setf (yas--snippet-exit snippet)
+                   (yas--make-exit (yas--make-marker (match-end 0))))
+             (push (cons (match-beginning 0) (yas--exit-marker (yas--snippet-exit snippet)))
+                   yas--dollar-regions))
+            (t
+             (let ((field (yas--snippet-find-field snippet number))
+                   (fom))
+               (if field
+                   (push
+                    (setq fom (yas--make-mirror
+                               (yas--make-marker (match-beginning 0))
+                               (yas--make-marker (match-beginning 0))
+                               nil))
+                    (yas--field-mirrors field))
+                 (push
+                  (setq fom (yas--make-field number
+                                             (yas--make-marker (match-beginning 0))
+                                             (yas--make-marker (match-beginning 0))
+                                             nil))
+                  (yas--snippet-fields snippet)))
+               (yas--calculate-simple-fom-parentage snippet fom))
+             (push (cons (match-beginning 0) (match-end 0))
+                   yas--dollar-regions))))))
+
+(defun yas--delete-regions (regions)
+  "Sort disjuct REGIONS by start point, then delete from the back."
+  (mapc #'(lambda (reg)
+            (delete-region (car reg) (cdr reg)))
+        (sort regions
+              #'(lambda (r1 r2)
+                  (>= (car r1) (car r2))))))
+
+(defun yas--calculate-mirror-depth (mirror &optional traversed)
+  (let* ((parent (yas--mirror-parent-field mirror))
+         (parents-mirrors (and parent
+                               (yas--field-mirrors parent))))
+    (or (yas--mirror-depth mirror)
+        (setf (yas--mirror-depth mirror)
+              (cond ((memq mirror traversed) 0)
+                    ((and parent parents-mirrors)
+                     (1+ (cl-reduce
+                          #'max parents-mirrors
+                          :key (lambda (m)
+                                 (yas--calculate-mirror-depth
+                                  m (cons mirror traversed))))))
+                    (parent 1)
+                    (t 0))))))
+
+(defun yas--update-mirrors (snippet)
+  "Update all the mirrors of SNIPPET."
+  (yas--save-restriction-and-widen
+    (save-excursion
+      (cl-loop
+       for (field . mirror)
+       in (cl-sort
+           ;; Make a list of (FIELD . MIRROR).
+           (cl-mapcan (lambda (field)
+                        (mapcar (lambda (mirror)
+                                  (cons field mirror))
+                                (yas--field-mirrors field)))
+                      (yas--snippet-fields snippet))
+           ;; Then sort this list so that entries with mirrors with
+           ;; parent fields appear before.  This was important for
+           ;; fixing #290, and also handles the case where a mirror in
+           ;; a field causes another mirror to need reupdating.
+           #'> :key (lambda (fm) (yas--calculate-mirror-depth (cdr fm))))
+       ;; Before updating a mirror with a parent-field, maybe advance
+       ;; its start (#290).
+       do (let ((parent-field (yas--mirror-parent-field mirror)))
+            (when parent-field
+              (yas--advance-start-maybe mirror (yas--fom-start parent-field))))
+       ;; Update this mirror.
+       do (yas--mirror-update-display mirror field)
+       ;; Delay indenting until we're done all mirrors.  We must do
+       ;; this to avoid losing whitespace between fields that are
+       ;; still empty (i.e., they will be non-empty after updating).
+       when (eq yas-indent-line 'auto)
+       collect (cons (yas--mirror-start mirror) (yas--mirror-end mirror))
+       into indent-regions
+       ;; `yas--place-overlays' is needed since the active field and
+       ;; protected overlays might have been changed because of insertions
+       ;; in `yas--mirror-update-display'.
+       do (let ((active-field (yas--snippet-active-field snippet)))
+            (when active-field (yas--place-overlays snippet active-field)))
+       finally do
+       (let ((yas--inhibit-overlay-hooks t))
+         (cl-loop for (beg . end) in (cl-sort indent-regions #'< :key #'car)
+                  do (yas--indent-region beg end snippet)))))))
+
+(defun yas--mirror-update-display (mirror field)
+  "Update MIRROR according to FIELD (and mirror transform)."
+
+  (let* ((mirror-parent-field (yas--mirror-parent-field mirror))
+         (reflection (and (not (and mirror-parent-field
+                                    (yas--field-modified-p mirror-parent-field)))
+                          (or (yas--apply-transform mirror field 'empty-on-nil)
+                              (yas--field-text-for-display field)))))
+    (when (and reflection
+               (not (string= reflection (buffer-substring-no-properties (yas--mirror-start mirror)
+                                                                        (yas--mirror-end mirror)))))
+      (goto-char (yas--mirror-start mirror))
+      (let ((yas--inhibit-overlay-hooks t))
+        (insert reflection))
+      (if (> (yas--mirror-end mirror) (point))
+          (delete-region (point) (yas--mirror-end mirror))
+        (set-marker (yas--mirror-end mirror) (point))
+        (yas--advance-start-maybe (yas--mirror-next mirror) (point))
+        ;; super-special advance
+        (yas--advance-end-of-parents-maybe mirror-parent-field (point))))))
+
+(defun yas--field-update-display (field)
+  "Much like `yas--mirror-update-display', but for fields."
+  (when (yas--field-transform field)
+    (let ((transformed (and (not (eq (yas--field-number field) 0))
+                            (yas--apply-transform field field))))
+      (when (and transformed
+                 (not (string= transformed (buffer-substring-no-properties (yas--field-start field)
+                                                                           (yas--field-end field)))))
+        (setf (yas--field-modified-p field) t)
+        (goto-char (yas--field-start field))
+        (let ((yas--inhibit-overlay-hooks t))
+          (insert transformed)
+          (if (> (yas--field-end field) (point))
+              (delete-region (point) (yas--field-end field))
+            (set-marker (yas--field-end field) (point))
+            (yas--advance-start-maybe (yas--field-next field) (point)))
+          t)))))
+
+
+;;; Post-command hook:
+;;
+(defun yas--post-command-handler ()
+  "Handles various yasnippet conditions after each command."
+  (when (and yas--watch-auto-fill-backtrace
+             (fboundp 'backtrace--print-frame)
+             (null yas--original-auto-fill-function)
+             (eq auto-fill-function 'yas--auto-fill))
+    (lwarn '(yasnippet auto-fill bug) :error
+           "`yas--original-auto-fill-function' unexpectedly nil! Please report this backtrace\n%S"
+           (with-output-to-string
+             (mapc #'backtrace--print-frame
+                     yas--watch-auto-fill-backtrace)))
+    ;; Don't pop up more than once in a session (still log though).
+    (defvar warning-suppress-types) ; `warnings' is autoloaded by `lwarn'.
+    (add-to-list 'warning-suppress-types '(yasnippet auto-fill bug)))
+  (condition-case err
+      (progn (yas--finish-moving-snippets)
+             (cond ((eq 'undo this-command)
+                    ;;
+                    ;; After undo revival the correct field is sometimes not
+                    ;; restored correctly, this condition handles that
+                    ;;
+                    (let* ((snippet (car (yas-active-snippets)))
+                           (target-field
+                            (and snippet
+                                 (cl-find-if-not
+                                  (lambda (field)
+                                    (yas--field-probably-deleted-p snippet field))
+                                  (remq nil
+                                        (cons (yas--snippet-active-field snippet)
+                                              (yas--snippet-fields snippet)))))))
+                      (when target-field
+                        (yas--move-to-field snippet target-field))))
+                   ((not (yas--undo-in-progress))
+                    ;; When not in an undo, check if we must commit the snippet
+                    ;; (user exited it).
+                    (yas--check-commit-snippet))))
+    ((debug error) (signal (car err) (cdr err)))))
+
+;;; Fancy docs:
+;;
+;; The docstrings for some functions are generated dynamically
+;; depending on the context.
+;;
+(put 'yas-expand  'function-documentation
+     '(yas--expand-from-trigger-key-doc t))
+(defun yas--expand-from-trigger-key-doc (context)
+  "A doc synthesizer for `yas--expand-from-trigger-key-doc'."
+  (let* ((yas-fallback-behavior (and context yas-fallback-behavior))
+         (fallback-description
+          (cond ((eq yas-fallback-behavior 'call-other-command)
+                 (let* ((fallback (yas--keybinding-beyond-yasnippet)))
+                   (or (and fallback
+                            (format "call command `%s'."
+                                    (pp-to-string fallback)))
+                       "do nothing (`yas-expand' doesn't override\nanything).")))
+                ((eq yas-fallback-behavior 'return-nil)
+                 "do nothing.")
+                (t "defer to `yas-fallback-behavior' (which see)."))))
+    (concat "Expand a snippet before point. If no snippet
+expansion is possible, "
+            fallback-description
+            "\n\nOptional argument FIELD is for non-interactive use and is an
+object satisfying `yas--field-p' to restrict the expansion to.")))
+
+(put 'yas-expand-from-keymap 'function-documentation
+     '(yas--expand-from-keymap-doc t))
+(defun yas--expand-from-keymap-doc (context)
+  "A doc synthesizer for `yas--expand-from-keymap-doc'."
+  (add-hook 'temp-buffer-show-hook #'yas--snippet-description-finish-runonce)
+  (concat "Expand/run snippets from keymaps, possibly falling back to original binding.\n"
+          (when (and context (eq this-command 'describe-key))
+            (let* ((vec (this-single-command-keys))
+                   (templates (cl-mapcan (lambda (table)
+                                           (yas--fetch table vec))
+                                         (yas--get-snippet-tables)))
+                   (yas--direct-keymaps nil)
+                   (fallback (key-binding vec)))
+              (concat "In this case, "
+                      (when templates
+                        (concat "these snippets are bound to this key:\n"
+                                (yas--template-pretty-list templates)
+                                "\n\nIf none of these expands, "))
+                      (or (and fallback
+                               (format "fallback `%s' will be called." (pp-to-string fallback)))
+                          "no fallback keybinding is called."))))))
+
+(defun yas--template-pretty-list (templates)
+  (let ((acc)
+        (yas-buffer-local-condition 'always))
+    (dolist (plate templates)
+      (setq acc (concat acc "\n*) "
+                        (propertize (concat "\\\\snippet `" (car plate) "'")
+                                    'yasnippet (cdr plate)))))
+    acc))
+
+(define-button-type 'help-snippet-def
+  :supertype 'help-xref
+  'help-function (lambda (template) (yas--visit-snippet-file-1 template))
+  'help-echo (purecopy "mouse-2, RET: find snippets's definition"))
+
+(defun yas--snippet-description-finish-runonce ()
+  "Final adjustments for the help buffer when snippets are concerned."
+  (yas--create-snippet-xrefs)
+  (remove-hook 'temp-buffer-show-hook
+               #'yas--snippet-description-finish-runonce))
+
+(defun yas--create-snippet-xrefs ()
+  (save-excursion
+    (goto-char (point-min))
+    (while (search-forward-regexp "\\\\\\\\snippet[ \s\t]+`\\([^']+\\)'" nil t)
+      (let ((template (get-text-property (match-beginning 1)
+                                         'yasnippet)))
+        (when template
+          (help-xref-button 1 'help-snippet-def template)
+          (delete-region (match-end 1) (match-end 0))
+          (delete-region (match-beginning 0) (match-beginning 1)))))))
+
+;;; Utils
+
+(defvar yas-verbosity 3
+  "Log level for `yas--message' 4 means trace most anything, 0 means nothing.")
+
+(defun yas--message (level message &rest args)
+  "When LEVEL is at or below `yas-verbosity', log MESSAGE and ARGS."
+  (when (>= yas-verbosity level)
+    (message "%s" (apply #'yas--format message args))))
+
+(defun yas--warning (format-control &rest format-args)
+  (let ((msg (apply #'format format-control format-args)))
+    (display-warning 'yasnippet msg :warning)
+    (yas--message 1 msg)))
+
+(defun yas--format (format-control &rest format-args)
+  (apply #'format (concat "[yas] " format-control) format-args))
+
+
+;;; Unloading
+
+(defvar unload-function-defs-list) ; loadhist.el
+
+(defun yasnippet-unload-function ()
+  "Disable minor modes when calling `unload-feature'."
+  ;; Disable `yas-minor-mode' everywhere it's enabled.
+  (yas-global-mode -1)
+  (save-current-buffer
+    (dolist (buffer (buffer-list))
+      (set-buffer buffer)
+      (when yas-minor-mode
+        (yas-minor-mode -1))))
+  ;; Remove symbol properties of all our functions, this avoids
+  ;; Bug#25088 in Emacs 25.1, where the compiler macro on
+  ;; `cl-defstruct' created functions hang around in the symbol plist
+  ;; and cause errors when loading again (we don't *need* to clean
+  ;; *all* symbol plists, but it's easier than being precise).
+  (dolist (def unload-function-defs-list)
+    (when (eq (car-safe def) 'defun)
+      (setplist (cdr def) nil)))
+  ;; Return nil so that `unload-feature' will take of undefining
+  ;; functions, and changing any buffers using `snippet-mode'.
+  nil)
+
+
+;;; Backward compatibility to yasnippet <= 0.7
+
+(defun yas-initialize ()
+  "For backward compatibility, enable `yas-minor-mode' globally."
+  (declare (obsolete "Use (yas-global-mode 1) instead." "0.8"))
+  (yas-global-mode 1))
+
+(defvar yas--backported-syms '(;; `defcustom's
+                             ;;
+                             yas-snippet-dirs
+                             yas-prompt-functions
+                             yas-indent-line
+                             yas-also-auto-indent-first-line
+                             yas-snippet-revival
+                             yas-triggers-in-field
+                             yas-fallback-behavior
+                             yas-choose-keys-first
+                             yas-choose-tables-first
+                             yas-use-menu
+                             yas-trigger-symbol
+                             yas-wrap-around-region
+                             yas-good-grace
+                             yas-visit-from-menu
+                             yas-expand-only-for-last-commands
+                             yas-field-highlight-face
+
+                             ;; these vars can be customized as well
+                             ;;
+                             yas-keymap
+                             yas-verbosity
+                             yas-extra-modes
+                             yas-key-syntaxes
+                             yas-after-exit-snippet-hook
+                             yas-before-expand-snippet-hook
+                             yas-buffer-local-condition
+                             yas-dont-activate
+
+                             ;; prompting functions
+                             ;;
+                             yas-x-prompt
+                             yas-ido-prompt
+                             yas-no-prompt
+                             yas-completing-prompt
+                             yas-dropdown-prompt
+
+                             ;; interactive functions
+                             ;;
+                             yas-expand
+                             yas-minor-mode
+                             yas-global-mode
+                             yas-direct-keymaps-reload
+                             yas-minor-mode-on
+                             yas-load-directory
+                             yas-reload-all
+                             yas-compile-directory
+                             yas-recompile-all
+                             yas-about
+                             yas-expand-from-trigger-key
+                             yas-expand-from-keymap
+                             yas-insert-snippet
+                             yas-visit-snippet-file
+                             yas-new-snippet
+                             yas-load-snippet-buffer
+                             yas-tryout-snippet
+                             yas-describe-tables
+                             yas-next-field-or-maybe-expand
+                             yas-next-field
+                             yas-prev-field
+                             yas-abort-snippet
+                             yas-exit-snippet
+                             yas-exit-all-snippets
+                             yas-skip-and-clear-or-delete-char
+                             yas-initialize
+
+                             ;; symbols that I "exported" for use
+                             ;; in snippets and hookage
+                             ;;
+                             yas-expand-snippet
+                             yas-define-snippets
+                             yas-define-menu
+                             yas-snippet-beg
+                             yas-snippet-end
+                             yas-modified-p
+                             yas-moving-away-p
+                             yas-substr
+                             yas-choose-value
+                             yas-key-to-value
+                             yas-throw
+                             yas-verify-value
+                             yas-field-value
+                             yas-text
+                             yas-selected-text
+                             yas-default-from-field
+                             yas-inside-string
+                             yas-unimplemented
+                             yas-define-condition-cache
+                             yas-hippie-try-expand
+
+                             ;; debug definitions
+                             ;; yas-debug-snippet-vars
+                             ;; yas-exterminate-package
+                             ;; yas-debug-test
+
+                             ;; testing definitions
+                             ;; yas-should-expand
+                             ;; yas-should-not-expand
+                             ;; yas-mock-insert
+                             ;; yas-make-file-or-dirs
+                             ;; yas-variables
+                             ;; yas-saving-variables
+                             ;; yas-call-with-snippet-dirs
+                             ;; yas-with-snippet-dirs
+)
+  "Backported yasnippet symbols.
+
+They are mapped to \"yas/*\" variants.")
+
+(when yas-alias-to-yas/prefix-p
+  (dolist (sym yas--backported-syms)
+    (let ((backported (intern (replace-regexp-in-string "\\`yas-" "yas/" (symbol-name sym)))))
+      (when (boundp sym)
+        (make-obsolete-variable backported sym "yasnippet 0.8")
+        (defvaralias backported sym))
+      (when (fboundp sym)
+        (make-obsolete backported sym "yasnippet 0.8")
+        (defalias backported sym))))
+  (make-obsolete 'yas/root-directory 'yas-snippet-dirs "yasnippet 0.8")
+  (defvaralias 'yas/root-directory 'yas-snippet-dirs))
+
+(defvar yas--exported-syms
+  (let (exported)
+    (mapatoms (lambda (atom)
+                (if (and (or (and (boundp atom)
+                                  (not (get atom 'byte-obsolete-variable)))
+                             (and (fboundp atom)
+                                  (not (get atom 'byte-obsolete-info))))
+                         (string-match-p "\\`yas-[^-]" (symbol-name atom)))
+                    (push atom exported))))
+    exported)
+  "Exported yasnippet symbols.
+
+i.e. the ones with \"yas-\" single dash prefix. I will try to
+keep them in future yasnippet versions and other elisp libraries
+can more or less safely rely upon them.")
+
+
+(provide 'yasnippet)
+;; Local Variables:
+;; coding: utf-8
+;; indent-tabs-mode: nil
+;; End:
+;;; yasnippet.el ends here