code.delx.au - gnu-emacs-elpa/blob - packages/ada-mode/ada-wisi-opentoken.el

   1 ;;; ada-wisi-opentoken.el --- An indentation function for ada-wisi that indents OpenToken
   2 ;; grammar statements nicely.
   3
   4 ;; Copyright (C) 2013  Free Software Foundation, Inc.
   5
   6 ;; This file is part of GNU Emacs.
   7
   8 ;; GNU Emacs is free software: you can redistribute it and/or modify
   9 ;; it under the terms of the GNU General Public License as published by
  10 ;; the Free Software Foundation, either version 3 of the License, or
  11 ;; (at your option) any later version.
  12
  13 ;; GNU Emacs is distributed in the hope that it will be useful,
  14 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;; GNU General Public License for more details.
  17
  18 ;; You should have received a copy of the GNU General Public License
  19 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  20
  21
  22 ;;; Commentary:
  23
  24 ;; This is an example of a user-added indentation rule.
  25 ;;
  26 ;; In ~/.emacs (or project-specific config):
  27 ;; (require 'ada-wisi-opentoken)
  28 ;;
  29 ;; In each file that declares OpenToken grammars:
  30 ;;
  31 ;; Local Variables:
  32 ;; ada-indent-opentoken: t
  33 ;; End:
  34
  35 ;;; Code:
  36
  37 (require 'ada-mode)
  38 (require 'wisi)
  39
  40 (defcustom ada-indent-opentoken nil
  41   "If non-nil, apply `ada-wisi-opentoken' indentation rule."
  42   :type  'boolean
  43   :group 'ada-indentation
  44   :safe  'booleanp)
  45 (make-variable-buffer-local 'ada-indent-opentoken)
  46
  47 (defun ada-wisi-opentoken ()
  48   "Return appropriate indentation (an integer column) for continuation lines in an OpenToken grammar statement."
  49   ;; We don't do any checking to see if we actually are in an
  50   ;; OpenToken grammar statement, since this rule should only be
  51   ;; included in package specs that exist solely to define OpenToken
  52   ;; grammar fragments.
  53   (when ada-indent-opentoken
  54     (save-excursion
  55       (let ((token-text (nth 1 (wisi-backward-token))))
  56         (cond
  57          ((equal token-text "<=")
  58           (back-to-indentation)
  59           (+ (current-column) ada-indent-broken))
  60
  61          ((member token-text '("+" "&"))
  62           (while (not (equal "<=" (nth 1 (wisi-backward-token)))))
  63           (back-to-indentation)
  64           (+ (current-column) ada-indent-broken))
  65          )))))
  66
  67 (defun ada-wisi-opentoken-setup ()
  68   (add-to-list 'wisi-indent-calculate-functions 'ada-wisi-opentoken))
  69
  70 ;; This must be after ada-wisi-setup on ada-mode-hook, because
  71 ;; ada-wisi-setup resets wisi-indent-calculate-functions
  72 (add-hook 'ada-mode-hook 'ada-wisi-opentoken-setup t)
  73
  74 (add-to-list 'ada-align-rules
  75              '(ada-opentoken
  76                (regexp  . "[^=]\\(\\s-*\\)<=")
  77                (valid   . (lambda() (not (ada-in-comment-p))))
  78                (modes   . '(ada-mode))))
  79
  80 (provide 'ada-wisi-opentoken)
  81 ;; end of file