6 files changed, 210 insertions, 0 deletions
diff --git a/tools/emacs-pkgs/dottime/default.nix b/tools/emacs-pkgs/dottime/default.nix
new file mode 100644
index 000000000000..b09756dea560
--- /dev/null
+++ b/tools/emacs-pkgs/dottime/default.nix
@@ -0,0 +1,7 @@
+{ pkgs, ... }:
+
+pkgs.third_party.emacsPackagesNg.trivialBuild rec {
+  pname = "dottime";
+  version = "1.0";
+  src = ./dottime.el;
+}
diff --git a/tools/emacs-pkgs/dottime/dottime.el b/tools/emacs-pkgs/dottime/dottime.el
new file mode 100644
index 000000000000..7caeb2f2c440
--- /dev/null
+++ b/tools/emacs-pkgs/dottime/dottime.el
@@ -0,0 +1,59 @@
+;;; dottime.el --- use dottime in the modeline
+;;
+;; Copyright (C) 2019 Google Inc.
+;;
+;; Author: Vincent Ambo <tazjin@google.com>
+;; Version: 1.0
+;; Package-Requires: (cl-lib)
+;;
+;;; Commentary:
+;;
+;; This package changes the display of time in the modeline to use
+;; dottime (see https://dotti.me/) instead of the standard time
+;; display.
+;;
+;; Modeline dottime display is enabled by calling
+;; `dottime-display-mode' and dottime can be used in Lisp code via
+;; `dottime-format'.
+
+(require 'cl-lib)
+(require 'time)
+
+(defun dottime--format-string ()
+  "Creates the dottime format string for `format-time-string'
+  based on the local timezone."
+
+  (let* ((offset-sec (car (current-time-zone)))
+         (offset-hours (/ offset-sec 60 60)))
+    (if (/= offset-hours 0)
+        (concat "%m-%dT%H·%M" (format "%0+3d" offset-hours))
+      "%m-%dT%H·%M")))
+
+(defun dottime--display-time-update-advice (orig)
+  "Function used as advice to `display-time-update' with a
+  rebound definition of `format-time-string' that renders all
+  timestamps as dottime."
+
+  (cl-letf* ((format-orig (symbol-function 'format-time-string))
+             ((symbol-function 'format-time-string)
+              (lambda (&rest _)
+                (funcall format-orig (dottime--format-string) nil t))))
+    (funcall orig)))
+
+(defun dottime-format (&optional time)
+  "Format the given TIME in dottime. If TIME is nil, the current
+  time will be used."
+
+  (format-time-string (dottime--format-string) time t))
+
+(defun dottime-display-mode (arg)
+  "Enable time display as dottime. Disables dottime if called
+  with prefix 0 or nil."
+
+  (interactive "p")
+  (if (or (eq arg 0) (eq arg nil))
+      (advice-remove 'display-time-update #'dottime--display-time-update-advice)
+    (advice-add 'display-time-update :around #'dottime--display-time-update-advice))
+  (display-time-update))
+
+(provide 'dottime)
diff --git a/tools/emacs-pkgs/nix-util/default.nix b/tools/emacs-pkgs/nix-util/default.nix
new file mode 100644
index 000000000000..0e314ae71966
--- /dev/null
+++ b/tools/emacs-pkgs/nix-util/default.nix
@@ -0,0 +1,7 @@
+{ pkgs, ... }:
+
+pkgs.third_party.emacsPackagesNg.trivialBuild rec {
+  pname = "nix-util";
+  version = "1.0";
+  src = ./nix-util.el;
+}
diff --git a/tools/emacs-pkgs/nix-util/nix-util.el b/tools/emacs-pkgs/nix-util/nix-util.el
new file mode 100644
index 000000000000..533e7e6f34c9
--- /dev/null
+++ b/tools/emacs-pkgs/nix-util/nix-util.el
@@ -0,0 +1,67 @@
+;;; nix-util.el --- Utilities for dealing with Nix code. -*- lexical-binding: t; -*-
+;;
+;; Copyright (C) 2019 Google Inc.
+;;
+;; Author: Vincent Ambo <tazjin@google.com>
+;; Version: 1.0
+;; Package-Requires: (json map)
+;;
+;;; Commentary:
+;;
+;; This package adds some functionality that I find useful when
+;; working in Nix buffers.
+
+(require 'json)
+(require 'map)
+
+(defun nix/prefetch-github (owner repo) ; TODO(tazjin): support different branches
+  "Fetch the master branch of a GitHub repository and insert the
+  call to `fetchFromGitHub' at point."
+
+  (interactive "sOwner: \nsRepository: ")
+
+  (let* (;; Keep these vars around for output insertion
+         (point (point))
+         (buffer (current-buffer))
+         (name (concat "github-fetcher/" owner "/" repo))
+         (outbuf (format "*%s*" name))
+         (errbuf (get-buffer-create "*github-fetcher/errors*"))
+         (cleanup (lambda ()
+                    (kill-buffer outbuf)
+                    (kill-buffer errbuf)
+                    (with-current-buffer buffer
+                      (read-only-mode -1))))
+         (prefetch-handler
+          (lambda (_process event)
+            (unwind-protect
+                (pcase event
+                  ("finished\n"
+                   (let* ((json-string (with-current-buffer outbuf
+                                         (buffer-string)))
+                          (result (json-parse-string json-string)))
+                     (with-current-buffer buffer
+                       (goto-char point)
+                       (map-let (("rev" rev) ("sha256" sha256)) result
+                         (read-only-mode -1)
+                         (insert (format "fetchFromGitHub {
+  owner = \"%s\";
+  repo = \"%s\";
+  rev = \"%s\";
+  sha256 = \"%s\";
+};" owner repo rev sha256))
+                         (indent-region point (point))))))
+                  (_ (with-current-buffer errbuf
+                       (error "Failed to prefetch %s/%s: %s"
+                              owner repo (buffer-string)))))
+              (funcall cleanup)))))
+
+    ;; Fetching happens asynchronously, but we'd like to make sure the
+    ;; point stays in place while that happens.
+    (read-only-mode)
+    (make-process :name name
+                  :buffer outbuf
+                  :command `("nix-prefetch-github" ,owner ,repo)
+                  :stderr errbuf
+                  :sentinel prefetch-handler)))
+
+(provide 'nix-util)
diff --git a/tools/emacs-pkgs/term-switcher/default.nix b/tools/emacs-pkgs/term-switcher/default.nix
new file mode 100644
index 000000000000..09b5353dc44e
--- /dev/null
+++ b/tools/emacs-pkgs/term-switcher/default.nix
@@ -0,0 +1,14 @@
+{ pkgs, ... }:
+
+with pkgs.third_party.emacsPackagesNg;
+
+melpaBuild rec {
+  pname = "term-switcher";
+  version = "1.0";
+  src = ./term-switcher.el;
+  packageRequires = [ dash ivy s vterm ];
+
+  recipe = builtins.toFile "recipe" ''
+    (term-switcher :fetcher github :repo "tazjin/depot")
+  '';
+}
diff --git a/tools/emacs-pkgs/term-switcher/term-switcher.el b/tools/emacs-pkgs/term-switcher/term-switcher.el
new file mode 100644
index 000000000000..67595474fa86
--- /dev/null
+++ b/tools/emacs-pkgs/term-switcher/term-switcher.el
@@ -0,0 +1,56 @@
+;;; term-switcher.el --- Easily switch between open vterms
+;;
+;; Copyright (C) 2019 Google Inc.
+;;
+;; Author: Vincent Ambo <tazjin@google.com>
+;; Version: 1.1
+;; Package-Requires: (dash ivy s vterm)
+;;
+;;; Commentary:
+;;
+;; This package adds a function that lets users quickly switch between
+;; different open vterms via ivy.
+
+(require 'dash)
+(require 'ivy)
+(require 's)
+(require 'vterm)
+
+(defgroup term-switcher nil
+  "Customization options `term-switcher'.")
+
+(defcustom term-switcher-buffer-prefix "vterm<"
+  "String prefix for vterm terminal buffers. For example, if you
+  set your titles to match `vterm<...>' a useful prefix might be
+  `vterm<'."
+  :type '(string)
+  :group 'term-switcher)
+
+(defun ts/open-or-create-vterm (buffer-name)
+  "Switch to the buffer with BUFFER-NAME or create a new vterm
+  buffer."
+  (let ((buffer (get-buffer buffer-name)))
+    (if (not buffer)
+        (vterm)
+      (switch-to-buffer buffer))))
+
+(defun ts/is-vterm-buffer (buffer)
+  "Determine whether BUFFER runs a vterm."
+  (equal 'vterm-mode (buffer-local-value 'major-mode buffer)))
+
+(defun ts/switch-to-terminal ()
+  "Switch to an existing vterm buffer or create a new one."
+
+  (interactive)
+  (let ((terms (-map #'buffer-name
+                     (-filter #'ts/is-vterm-buffer (buffer-list)))))
+    (if terms
+        (ivy-read "Switch to vterm: "
+                  (cons "New vterm" terms)
+                  :caller 'ts/switch-to-terminal
+                  :preselect (s-concat "^" term-switcher-buffer-prefix)
+                  :require-match t
+                  :action #'ts/open-or-create-vterm)
+      (vterm))))
+
+(provide 'term-switcher)