diff options
Diffstat (limited to 'configs/shared/emacs/.emacs.d/elpa/circe-20180525.1231/shorten.el')
-rw-r--r-- | configs/shared/emacs/.emacs.d/elpa/circe-20180525.1231/shorten.el | 223 |
1 files changed, 223 insertions, 0 deletions
diff --git a/configs/shared/emacs/.emacs.d/elpa/circe-20180525.1231/shorten.el b/configs/shared/emacs/.emacs.d/elpa/circe-20180525.1231/shorten.el new file mode 100644 index 000000000000..1ba6085b9c91 --- /dev/null +++ b/configs/shared/emacs/.emacs.d/elpa/circe-20180525.1231/shorten.el @@ -0,0 +1,223 @@ +;;; shorten.el --- component-wise string shortener + +;; Copyright (C) 2013 John J Foerch <jjfoerch@earthlink.net> + +;; Keywords: extensions +;; Author: John J Foerch <jjfoerch@earthlink.net> +;; URL: https://github.com/jorgenschaefer/circe/blob/master/shorten.el + +;; 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: + +;; This is a component-wise string shortener, meaning that, given a list +;; of strings, it breaks each string into parts, then computes shortest +;; prefix of each part with respect to others of the same 'depth', such +;; that when joined back together, the shortened form of the whole string +;; remains unique within the resulting list. Many styles of shortening +;; are made possible via three functions that the caller may provide: the +;; split function, the join function, and the validate-component function. +;; +;; Strings are broken with the value of `shorten-split-function' (a +;; procedure string->list), and shortened components are rejoined with the +;; value of `shorten-join-function' (a procedure list->string[*]). The +;; default split and join functions break the string on word boundaries, +;; and rejoin on the empty string. Potential shortened forms of +;; components are tested with `shorten-validate-component-function'; its +;; default value passes only if its argument contains at least one +;; word-constituent character (regexp \w), meaning that by default, +;; components consisting entirely of non-word characters will not be +;; shortened, and components that start with non-word characters will only +;; be shortened so much that they have at least one word-constituent +;; character in them. +;; +;; The main entry point is `shorten-strings', which takes a list of strings +;; as its argument and returns an alist ((STRING . SHORTENED-STRING) ...). +;; +;; [*] Also takes a second argument; see docstring of +;; `shorten-join-function'. + +;;; History: + +;; - Version 0.1 (March 7, 2013): initial release + +;;; Code: + +;; Tree utils +;; +(defsubst shorten-make-tree-root () + (cons nil nil)) + +(defsubst shorten-tree-make-entry (token short full) + (list token short full nil)) + +(defsubst shorten-tree-token (entry) + (car entry)) + +(defsubst shorten-tree-fullname (entry) + (nth 2 entry)) + +(defsubst shorten-tree-descendants (entry) + (nthcdr 3 entry)) + +(defsubst shorten-tree-set-shortened (entry short) + (setcar (cdr entry) short)) + +(defsubst shorten-tree-set-fullname (entry full) + (setcar (nthcdr 2 entry) full)) + +(defsubst shorten-tree-insert (node item) + (when (car node) + (setcdr node (cons (car node) (cdr node)))) + (setcar node item)) + + +;; Caller configuration +;; +(defun shorten-split (s) + (split-string s "\\b" t)) + +(defun shorten-join (lst &optional tail-count) + (mapconcat #'identity lst "")) + +(defun shorten-join-sans-tail (lst tail-count) + "A shorten-join that drops unnecessary tail components." + (shorten-join (butlast lst tail-count))) + +(defun shorten-validate-component (str) + (string-match-p "\\w" str)) + +(defvar shorten-split-function #'shorten-split + "Value should be a function of string->list that breaks a +string into components. The default breaks on word-boundaries. +To get simple prefix shortening, bind this to `list'. + +Users should not generally change the global value of this +variable; instead, bind it dynamically around calls to +`shorten-strings'.") + +(defvar shorten-join-function #'shorten-join + "A function that takes a list of components and a tail-count, +and returns a joined string. Tail-count is the number of +components on the end of the list that are not needed to uniquify +the result, and so may be safely dropped if aggressive shortening +is desired. The default preserves tail components, and joins the +list on the empty string. + +Users should not generally change the global value of this +variable; instead, bind it dynamically around calls to +`shorten-strings'.") + +(defvar shorten-validate-component-function #'shorten-validate-component + "Predicate that returns t if a proposed shortened form of a +single component is acceptable, nil if a longer one should be +tried. The default validates only when the candidate contains at +least one word-constituent character, thus strings consisting of +punctuation will not be shortened. For aggressive shortening, +bind to a procedure that always returns t. + +Users should not generally change the global value of this +variable; instead, bind it dynamically around calls to +`shorten-strings'.") + + +;; Main procedures +;; +(defun shorten-one (str others) + "Return shortest unique prefix of STR among OTHERS, or STR if +it cannot be shortened. If STR is a member of OTHERS (tested +with `eq') that entry is ignored. The value of +`shorten-validate-component-function' will be used to validate +any prefix." + (let ((max (length str)) + (len 1)) + (or (catch 'return + (while (< len max) + (let ((prefix (substring str 0 len))) + (when (funcall shorten-validate-component-function prefix) + (when (catch 'return + (dolist (other others t) + (when (and (>= (length other) len) + (string= (substring other 0 len) prefix) + (not (eq other str))) + (throw 'return nil)))) + (throw 'return prefix))) + (setq len (1+ len))))) + str))) + +(defun shorten-walk-internal (node path tail-count result-out) + (let ((others (mapcar #'car node))) + (setq tail-count (if (cdr node) 0 (1+ tail-count))) + (dolist (entry node) + (let* ((token (shorten-tree-token entry)) + (shortened (shorten-one token others)) + (path (cons shortened path)) + (fullname (shorten-tree-fullname entry)) + (descendants (shorten-tree-descendants entry)) + (have-descendants (not (equal '(nil) descendants)))) + (shorten-tree-set-shortened entry shortened) + ;; if this entry has a fullname, add to result-out + (when fullname + (let ((joined (funcall shorten-join-function + (reverse path) + (if have-descendants 0 tail-count)))) + (shorten-tree-insert result-out (cons fullname joined)))) + ;; if this entry has descendants, recurse + (when have-descendants + (shorten-walk-internal descendants path + (if fullname -1 tail-count) + result-out)))))) + +(defun shorten-walk (tree) + "Takes a tree of the type made by `shorten-make-tree' and +returns an alist ((STRING . SHORTENED-STRING) ...). Uses +`shorten-join-function' to join shortened components back +together into SHORTENED-STRING. See also +`shorten-validate-component-function'." + (let ((result-out (shorten-make-tree-root))) + (shorten-walk-internal tree '() -1 result-out) + (if (equal '(nil) result-out) nil result-out))) + +(defun shorten-make-tree (strings) + "Takes a list of strings and returns a tree of the type used by +`shorten-walk' to generate shortened strings. Uses +`shorten-split-function' to split the strings." + (let ((tree (shorten-make-tree-root))) + (dolist (s strings) + (let ((node tree) + (tokens (funcall shorten-split-function s)) + (entry nil)) + ;; create a path in tree for tokens + (dolist (token tokens) + (setq entry (assoc token node)) + (when (not entry) + (setq entry (shorten-tree-make-entry token nil nil)) + (shorten-tree-insert node entry)) + (setq node (shorten-tree-descendants entry))) + ;; for the last token, set 'fullname' + (shorten-tree-set-fullname entry s))) + (if (equal tree '(nil)) nil tree))) + +;;;###autoload +(defun shorten-strings (strings) + "Takes a list of strings and returns an alist ((STRING +. SHORTENED-STRING) ...). Uses `shorten-split-function' to split +the strings, and `shorten-join-function' to join shortened +components back together into SHORTENED-STRING. See also +`shorten-validate-component-function'." + (shorten-walk (shorten-make-tree strings))) + + +(provide 'shorten) +;;; shorten.el ends here |