lisp/progmodes/idlw-complete-structtag.el

   1 ;;; idlw-complete-structtag.el --- Completion of structure tags.
   2 ;; Copyright (c) 2001, 2002, 2003, 2004, 2005 Free Software Foundation
   3
   4 ;; Author: Carsten Dominik <dominik@science.uva.nl>
   5 ;; Maintainer: J.D. Smith <jdsmith@as.arizona.edu>
   6 ;; Version: 1.2
   7 ;; Keywords: languages
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Completion of structure tags can be done automatically in the
  29 ;; shell, since the list of tags can be determined dynamically through
  30 ;; interaction with IDL.
  31
  32 ;; Completion of structure tags in a source buffer is highly ambiguous
  33 ;; since you never know what kind of structure a variable will hold at
  34 ;; runtime.  To make this feature useful in source buffers, we need a
  35 ;; special assumption/convention.  We will assume that the structure is
  36 ;; defined in the same buffer and directly assigned to the correct
  37 ;; variable.  This is mainly useful for applications in which there is one
  38 ;; main structure which contains a large amount of information (and many
  39 ;; tags).  For example, many widget applications define a "state" structure
  40 ;; that contains all important data about the application.  The different
  41 ;; routines called by the event handler then use this structure.  If you
  42 ;; use the same variable name for this structure throughout your
  43 ;; application (a good idea for many reasons), IDLWAVE can support
  44 ;; completion for its tags.
  45 ;;
  46 ;; This file is a completion plugin which implements this kind of
  47 ;; completion. It is also an example which shows how completion plugins
  48 ;; should be programmed.
  49 ;;
  50 ;; New versions of IDLWAVE, documentation, and more information available
  51 ;; from:
  52 ;;                 http://idlwave.org
  53 ;;
  54 ;; INSTALLATION
  55 ;; ============
  56 ;; Put this file on the emacs load path and load it with the following
  57 ;; line in your .emacs file:
  58 ;;
  59 ;;   (add-hook 'idlwave-load-hook
  60 ;;             (lambda () (require 'idlw-complete-structtag)))
  61 ;;
  62 ;; DESCRIPTION
  63 ;; ===========
  64 ;; Suppose your IDL program contains something like
  65 ;;
  66 ;;     myvar = state.a*
  67 ;;
  68 ;; where the star marks the cursor position.  If you now press the
  69 ;; completion key M-TAB, IDLWAVE searches the current file for a
  70 ;; structure definition
  71 ;;
  72 ;;   state = {tag1:val1, tag2:val2, ...}
  73 ;;
  74 ;; and offers the tags for completion.
  75 ;;
  76 ;; In the idlwave shell, idlwave sends a "print,tag_names()" for the
  77 ;; variable to idl and determines the current tag list dynamically.
  78 ;;
  79 ;; Notes
  80 ;; -----
  81 ;;  - The structure definition assignment "state = {...}" must use the
  82 ;;    same variable name as the the completion location "state.*".
  83 ;;  - The structure definition must be in the same file.
  84 ;;  - The structure definition is searched backwards and then forward
  85 ;;    from the current position, until a definition with tags is found.
  86 ;;  - The file is parsed again for each new completion variable and location.
  87 ;;  - You can force an update of the tag list with the usual command
  88 ;;    to update routine info in IDLWAVE: C-c C-i
  89
  90
  91 ;; Some variables to identify the previously used structure
  92 (defvar idlwave-current-tags-var nil)
  93 (defvar idlwave-current-tags-buffer nil)
  94 (defvar idlwave-current-tags-completion-pos nil)
  95
  96 ;; The tag list used for completion will be stored in the following vars
  97 (defvar idlwave-current-struct-tags nil)
  98 (defvar idlwave-sint-structtags nil)
  99
 100 ;; Create the sintern type for structure talks
 101 (idlwave-new-sintern-type 'structtag)
 102
 103 ;; Hook the plugin into idlwave
 104 (add-to-list 'idlwave-complete-special 'idlwave-complete-structure-tag)
 105 (add-hook 'idlwave-update-rinfo-hook 'idlwave-structtag-reset)
 106
 107 ;;; The main code follows below
 108
 109 (defun idlwave-complete-structure-tag ()
 110   "Complete a structure tag.
 111 This works by looking in the current file for a structure assignment to a
 112 variable with the same name and takes the tags from there.  Quite useful
 113 for big structures like the state variables of a widget application.
 114
 115 In the idlwave shell, the current content of the variable is used to get
 116 an up-to-date completion list."
 117   (interactive)
 118   (let ((pos (point))
 119         start
 120         (case-fold-search t))
 121     (if (save-excursion
 122           ;; Check if the context is right.
 123           ;; In the shell, this could be extended to expressions like
 124           ;; x[i+4].name.g*.  But it is complicated because we would have
 125           ;; to really parse this expression.  For now, we allow only
 126           ;; substructures, like "aaa.bbb.ccc.ddd"
 127           (skip-chars-backward "[a-zA-Z0-9._$]")
 128           (setq start (point)) ;; remember the start of the completion pos.
 129           (and (< (point) pos)
 130                (not (equal (char-before) ?!)) ; no sysvars
 131                (looking-at "\\([a-zA-Z][.a-zA-Z0-9_]*\\)\\.")
 132                (>= pos (match-end 0))
 133                (not (string= (downcase (match-string 1)) "self"))))
 134         (let* ((var (downcase (match-string 1))))
 135           ;; Check if we need to update the "current" structure.  Basically we
 136           ;; do it always, except for subsequent completions at the same
 137           ;; spot, to save a bit of time.  Implementation:  We require
 138           ;; an update if
 139           ;; - the variable is different or
 140           ;; - the buffer is different or
 141           ;; - we are completing at a different position
 142           (if (or (not (string= var (or idlwave-current-tags-var "@")))
 143                   (not (eq (current-buffer) idlwave-current-tags-buffer))
 144                   (not (equal start idlwave-current-tags-completion-pos)))
 145               (idlwave-prepare-structure-tag-completion var))
 146           (setq idlwave-current-tags-completion-pos start)
 147           (setq idlwave-completion-help-info
 148                 (list 'idlwave-complete-structure-tag-help))
 149           (idlwave-complete-in-buffer 'structtag 'structtag
 150                                       idlwave-current-struct-tags nil
 151                                       "Select a structure tag" "structure tag")
 152           t) ; we did the completion: return t to skip other completions
 153       nil))) ; return nil to allow looking for other ways to complete
 154
 155 (defun idlwave-structtag-reset ()
 156   "Force an update of the current structure tag list upon next use."
 157   (setq idlwave-current-tags-buffer nil))
 158
 159 (defvar idlwave-structtag-struct-location nil
 160   "The location of the structure definition, for help display.")
 161
 162 (defun idlwave-prepare-structure-tag-completion (var)
 163   "Find and parse the tag list for structure tag completion."
 164   ;; This works differently in source buffers and in the shell
 165   (if (eq major-mode 'idlwave-shell-mode)
 166       ;; OK, we are in the shell, do it dynamically
 167       (progn
 168         (message "preparing shell tags")
 169         ;; The following call puts the tags into `idlwave-current-struct-tags'
 170         (idlwave-complete-structure-tag-query-shell var)
 171         ;; initialize
 172         (setq idlwave-sint-structtags nil
 173               idlwave-current-tags-buffer (current-buffer)
 174               idlwave-current-tags-var var
 175               idlwave-structtag-struct-location (point)
 176               idlwave-current-struct-tags
 177               (mapcar (lambda (x)
 178                         (list (idlwave-sintern-structtag x 'set)))
 179                       idlwave-current-struct-tags))
 180         (if (not idlwave-current-struct-tags)
 181             (error "Cannot complete structure tags of variable %s" var)))
 182     ;; Not the shell, so probably a source buffer.
 183     (unless
 184         (catch 'exit
 185           (save-excursion
 186             (goto-char (point-max))
 187             ;; Find possible definitions of the structure.
 188             (while (idlwave-find-structure-definition var nil 'all)
 189               (let ((tags (idlwave-struct-tags)))
 190                 (when tags
 191                   ;; initialize
 192                   (setq idlwave-sint-structtags nil
 193                         idlwave-current-tags-buffer (current-buffer)
 194                         idlwave-current-tags-var var
 195                         idlwave-structtag-struct-location (point)
 196                         idlwave-current-struct-tags
 197                         (mapcar (lambda (x)
 198                                   (list (idlwave-sintern-structtag x 'set)))
 199                                 tags))
 200                   (throw 'exit t))))))
 201       (error "Cannot complete structure tags of variable %s" var))))
 202
 203 (defun idlwave-complete-structure-tag-query-shell (var)
 204   "Ask the shell for the tags of the structure in variable or expression VAR."
 205   (idlwave-shell-send-command
 206    (format "if size(%s,/TYPE) eq 8 then print,tag_names(%s)" var var)
 207    'idlwave-complete-structure-tag-get-tags-from-help
 208    'hide 'wait))
 209
 210 (defvar idlwave-shell-prompt-pattern)
 211 (defvar idlwave-shell-command-output)
 212 (defun idlwave-complete-structure-tag-get-tags-from-help ()
 213   "Filter structure tag name output, result to `idlwave-current-struct-tags'."
 214     (setq idlwave-current-struct-tags
 215           (if (string-match (concat "tag_names(.*) *\n"
 216                                     "\\(\\(.*[\r\n]?\\)*\\)"
 217                                     "\\(" idlwave-shell-prompt-pattern "\\)")
 218                             idlwave-shell-command-output)
 219               (split-string (match-string 1 idlwave-shell-command-output)))))
 220
 221
 222 ;; Fake help in the source buffer for structure tags.
 223 ;; kwd and name are global-variables here.
 224 (defvar name)
 225 (defvar kwd)
 226 (defvar idlwave-help-do-struct-tag)
 227 (defun idlwave-complete-structure-tag-help (mode word)
 228   (cond
 229    ((eq mode 'test)
 230     ;; fontify only in source buffers, not in the shell.
 231     (not (equal idlwave-current-tags-buffer
 232                 (get-buffer (idlwave-shell-buffer)))))
 233    ((eq mode 'set)
 234     (setq kwd word
 235           idlwave-help-do-struct-tag idlwave-structtag-struct-location))
 236    (t (error "This should not happen"))))
 237
 238 (provide 'idlw-complete-structtag)
 239
 240 ;;; idlw-complete-structtag.el ends here
 241
 242
 243 ;; arch-tag: d1f9e55c-e504-4187-9c31-3c3651fa4bfa