misc/ruby-electric.el

   1 ;; -*-Emacs-Lisp-*-
   2 ;;
   3 ;; ruby-electric.el --- electric editing commands for ruby files
   4 ;;
   5 ;; Copyright (C) 2005 by Dee Zsombor <dee dot zsombor at gmail dot com>.
   6 ;; Released under same license terms as Ruby.
   7 ;;
   8 ;; Due credit: this work was inspired by a code snippet posted by
   9 ;; Frederick Ros at http://rubygarden.org/ruby?EmacsExtensions.
  10 ;;
  11 ;; Following improvements where added:
  12 ;;
  13 ;;       - handling of strings of type 'here document'
  14 ;;       - more keywords, with special handling for 'do'
  15 ;;       - packaged into a minor mode
  16 ;;
  17 ;; Usage:
  18 ;;
  19 ;;    0) copy ruby-electric.el into directory where emacs can find it.
  20 ;;
  21 ;;    1) modify your startup file (.emacs or whatever) by adding
  22 ;;       following line:
  23 ;;
  24 ;;            (require 'ruby-electric)
  25 ;;
  26 ;;       note that you need to have font lock enabled beforehand.
  27 ;;
  28 ;;    2) toggle Ruby Electric Mode on/off with ruby-electric-mode.
  29 ;;
  30 ;; Changelog:
  31 ;;
  32 ;;  2005/Jan/14: inserts matching pair delimiters like {, [, (, ', ",
  33 ;;  ' and | .
  34 ;;
  35 ;;  2005/Jan/14: added basic Custom support for configuring keywords
  36 ;;  with electric closing.
  37 ;;
  38 ;;  2005/Jan/18: more Custom support for configuring characters for
  39 ;;  which matching expansion should occur.
  40 ;;
  41 ;;  2005/Jan/18: no longer uses 'looking-back' or regexp character
  42 ;;  classes like [:space:] since they are not implemented on XEmacs.
  43 ;;
  44 ;;  2005/Feb/01: explicitly provide default argument of 1 to
  45 ;;  'backward-word' as it requires it on Emacs 21.3
  46 ;;
  47 ;;  2005/Mar/06: now stored inside ruby CVS; customize pages now have
  48 ;;  ruby as parent; cosmetic fixes.
  49
  50
  51 (require 'ruby-mode)
  52
  53 (defgroup ruby-electric nil
  54   "Minor mode providing electric editing commands for ruby files"
  55   :group 'ruby)
  56
  57 (defconst ruby-electric-expandable-do-re
  58   "do\\s-$")
  59
  60 (defconst ruby-electric-expandable-bar
  61   "\\s-\\(do\\|{\\)\\s-+|")
  62
  63 (defvar ruby-electric-matching-delimeter-alist
  64   '((?\[ . ?\])
  65     (?\( . ?\))
  66     (?\' . ?\')
  67     (?\` . ?\`)
  68     (?\" . ?\")))
  69
  70 (defcustom ruby-electric-simple-keywords-re
  71   "\\(def\\|if\\|class\\|module\\|unless\\|case\\|while\\|do\\|until\\|for\\|begin\\)"
  72   "*Regular expresion matching keywords for which closing 'end'
  73 is to be inserted."
  74   :type 'regexp :group 'ruby-electric)
  75
  76 (defcustom ruby-electric-expand-delimiters-list '(all)
  77   "*List of contexts where matching delimiter should be
  78 inserted. The word 'all' will do all insertions."
  79   :type '(set :extra-offset 8
  80               (const :tag "Everything" all )
  81               (const :tag "Curly brace" ?\{ )
  82               (const :tag "Square brace" ?\[ )
  83               (const :tag "Round brace" ?\( )
  84               (const :tag "Quote" ?\' )
  85               (const :tag "Double quote" ?\" )
  86               (const :tag "Back quote" ?\` )
  87               (const :tag "Vertical bar" ?\| ))
  88   :group 'ruby-electric)
  89
  90 (defcustom ruby-electric-newline-before-closing-bracket nil
  91   "*Controls whether a newline should be inserted before the
  92 closing bracket or not."
  93   :type 'boolean :group 'ruby-electric)
  94
  95 (define-minor-mode ruby-electric-mode
  96   "Toggle Ruby Electric minor mode.
  97 With no argument, this command toggles the mode.  Non-null prefix
  98 argument turns on the mode.  Null prefix argument turns off the
  99 mode.
 100
 101 When Ruby Electric mode is enabled, an indented 'end' is
 102 heuristicaly inserted whenever typing a word like 'module',
 103 'class', 'def', 'if', 'unless', 'case', 'until', 'for', 'begin',
 104 'do'. Simple, double and back quotes as well as braces are paired
 105 auto-magically. Expansion does not occur inside comments and
 106 strings. Note that you must have Font Lock enabled."
 107   ;; initial value.
 108   nil
 109   ;;indicator for the mode line.
 110   " REl"
 111   ;;keymap
 112   ruby-mode-map
 113   (ruby-electric-setup-keymap))
 114
 115 (defun ruby-electric-setup-keymap()
 116   (define-key ruby-mode-map " " 'ruby-electric-space)
 117   (define-key ruby-mode-map "{" 'ruby-electric-curlies)
 118   (define-key ruby-mode-map "(" 'ruby-electric-matching-char)
 119   (define-key ruby-mode-map "[" 'ruby-electric-matching-char)
 120   (define-key ruby-mode-map "\"" 'ruby-electric-matching-char)
 121   (define-key ruby-mode-map "\'" 'ruby-electric-matching-char)
 122   (define-key ruby-mode-map "|" 'ruby-electric-bar))
 123
 124 (defun ruby-electric-space (arg)
 125   (interactive "P")
 126   (self-insert-command (prefix-numeric-value arg))
 127   (if (ruby-electric-space-can-be-expanded-p)
 128       (save-excursion
 129         (ruby-indent-line t)
 130         (newline)
 131         (ruby-insert-end))))
 132
 133 (defun ruby-electric-code-at-point-p()
 134   (and ruby-electric-mode
 135        (let* ((properties (text-properties-at (point))))
 136          (and (null (memq 'font-lock-string-face properties))
 137               (null (memq 'font-lock-comment-face properties))))))
 138
 139 (defun ruby-electric-string-at-point-p()
 140   (and ruby-electric-mode
 141        (consp (memq 'font-lock-string-face (text-properties-at (point))))))
 142
 143 (defun ruby-electric-is-last-command-char-expandable-punct-p()
 144   (or (memq 'all ruby-electric-expand-delimiters-list)
 145       (memq last-command-char ruby-electric-expand-delimiters-list)))
 146
 147 (defun ruby-electric-space-can-be-expanded-p()
 148   (if (ruby-electric-code-at-point-p)
 149       (let* ((ruby-electric-keywords-re
 150               (concat ruby-electric-simple-keywords-re "\\s-$"))
 151              (ruby-electric-single-keyword-in-line-re
 152               (concat "\\s-*" ruby-electric-keywords-re)))
 153         (save-excursion
 154           (backward-word 1)
 155           (or (looking-at ruby-electric-expandable-do-re)
 156               (and (looking-at ruby-electric-keywords-re)
 157                    (not (string= "do" (match-string 1)))
 158                    (progn
 159                      (beginning-of-line)
 160                      (looking-at ruby-electric-single-keyword-in-line-re))))))))
 161
 162
 163 (defun ruby-electric-curlies(arg)
 164   (interactive "P")
 165   (self-insert-command (prefix-numeric-value arg))
 166   (if (ruby-electric-is-last-command-char-expandable-punct-p)
 167       (cond ((ruby-electric-code-at-point-p)
 168              (insert " ")
 169              (save-excursion
 170                (if ruby-electric-newline-before-closing-bracket
 171                    (newline))
 172                (insert "}")))
 173             ((ruby-electric-string-at-point-p)
 174              (save-excursion
 175                (backward-char 1)
 176                (when (char-equal ?\# (preceding-char))
 177                  (forward-char 1)
 178                  (insert "}")))))))
 179
 180 (defun ruby-electric-matching-char(arg)
 181   (interactive "P")
 182   (self-insert-command (prefix-numeric-value arg))
 183   (and (ruby-electric-is-last-command-char-expandable-punct-p)
 184        (ruby-electric-code-at-point-p)
 185        (save-excursion
 186          (insert (cdr (assoc last-command-char
 187                              ruby-electric-matching-delimeter-alist))))))
 188
 189 (defun ruby-electric-bar(arg)
 190   (interactive "P")
 191   (self-insert-command (prefix-numeric-value arg))
 192   (and (ruby-electric-is-last-command-char-expandable-punct-p)
 193        (ruby-electric-code-at-point-p)
 194        (and (save-excursion (re-search-backward ruby-electric-expandable-bar nil t))
 195             (= (point) (match-end 0))) ;looking-back is missing on XEmacs
 196        (save-excursion
 197          (insert "|"))))
 198
 199
 200 (provide 'ruby-electric)