;;; idlw-complete-structtag.el --- Completion of structure tags. ;; Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 ;; Free Software Foundation, Inc. ;; Author: Carsten Dominik <dominik@astro.uva.nl> ;; Maintainer: J.D. Smith <jdsmith@as.arizona.edu> ;; Version: 1.2 ;; Keywords: languages ;; This file is part of GNU Emacs. ;; GNU Emacs 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 2, or (at your option) ;; any later version. ;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to the ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, ;; Boston, MA 02110-1301, USA. ;;; Commentary: ;; Completion of structure tags can be done automatically in the ;; shell, since the list of tags can be determined dynamically through ;; interaction with IDL. ;; Completion of structure tags in a source buffer is highly ambiguous ;; since you never know what kind of structure a variable will hold at ;; runtime. To make this feature useful in source buffers, we need a ;; special assumption/convention. We will assume that the structure is ;; defined in the same buffer and directly assigned to the correct ;; variable. This is mainly useful for applications in which there is one ;; main structure which contains a large amount of information (and many ;; tags). For example, many widget applications define a "state" structure ;; that contains all important data about the application. The different ;; routines called by the event handler then use this structure. If you ;; use the same variable name for this structure throughout your ;; application (a good idea for many reasons), IDLWAVE can support ;; completion for its tags. ;; ;; This file is a completion plugin which implements this kind of ;; completion. It is also an example which shows how completion plugins ;; should be programmed. ;; ;; New versions of IDLWAVE, documentation, and more information available ;; from: ;; http://idlwave.org ;; ;; INSTALLATION ;; ============ ;; Put this file on the emacs load path and load it with the following ;; line in your .emacs file: ;; ;; (add-hook 'idlwave-load-hook ;; (lambda () (require 'idlw-complete-structtag))) ;; ;; DESCRIPTION ;; =========== ;; Suppose your IDL program contains something like ;; ;; myvar = state.a* ;; ;; where the star marks the cursor position. If you now press the ;; completion key M-TAB, IDLWAVE searches the current file for a ;; structure definition ;; ;; state = {tag1:val1, tag2:val2, ...} ;; ;; and offers the tags for completion. ;; ;; In the idlwave shell, idlwave sends a "print,tag_names()" for the ;; variable to idl and determines the current tag list dynamically. ;; ;; Notes ;; ----- ;; - The structure definition assignment "state = {...}" must use the ;; same variable name as the the completion location "state.*". ;; - The structure definition must be in the same file. ;; - The structure definition is searched backwards and then forward ;; from the current position, until a definition with tags is found. ;; - The file is parsed again for each new completion variable and location. ;; - You can force an update of the tag list with the usual command ;; to update routine info in IDLWAVE: C-c C-i (require 'idlwave) ;; Some variables to identify the previously used structure (defvar idlwave-current-tags-var nil) (defvar idlwave-current-tags-buffer nil) (defvar idlwave-current-tags-completion-pos nil) ;; The tag list used for completion will be stored in the following vars (defvar idlwave-current-struct-tags nil) (defvar idlwave-sint-structtags nil) ;; Create the sintern type for structure talks (idlwave-new-sintern-type 'structtag) ;; Hook the plugin into idlwave (add-to-list 'idlwave-complete-special 'idlwave-complete-structure-tag) (add-hook 'idlwave-update-rinfo-hook 'idlwave-structtag-reset) ;;; The main code follows below (defvar idlwave-completion-help-info) (defun idlwave-complete-structure-tag () "Complete a structure tag. This works by looking in the current file for a structure assignment to a variable with the same name and takes the tags from there. Quite useful for big structures like the state variables of a widget application. In the idlwave shell, the current content of the variable is used to get an up-to-date completion list." (interactive) (let ((pos (point)) start (case-fold-search t)) (if (save-excursion ;; Check if the context is right. ;; In the shell, this could be extended to expressions like ;; x[i+4].name.g*. But it is complicated because we would have ;; to really parse this expression. For now, we allow only ;; substructures, like "aaa.bbb.ccc.ddd" (skip-chars-backward "[a-zA-Z0-9._$]") (setq start (point)) ;; remember the start of the completion pos. (and (< (point) pos) (not (equal (char-before) ?!)) ; no sysvars (looking-at "\\([a-zA-Z][.a-zA-Z0-9_]*\\)\\.") (>= pos (match-end 0)) (not (string= (downcase (match-string 1)) "self")))) (let* ((var (downcase (match-string 1)))) ;; Check if we need to update the "current" structure. Basically we ;; do it always, except for subsequent completions at the same ;; spot, to save a bit of time. Implementation: We require ;; an update if ;; - the variable is different or ;; - the buffer is different or ;; - we are completing at a different position (if (or (not (string= var (or idlwave-current-tags-var "@"))) (not (eq (current-buffer) idlwave-current-tags-buffer)) (not (equal start idlwave-current-tags-completion-pos))) (idlwave-prepare-structure-tag-completion var)) (setq idlwave-current-tags-completion-pos start) (setq idlwave-completion-help-info (list 'idlwave-complete-structure-tag-help)) (idlwave-complete-in-buffer 'structtag 'structtag idlwave-current-struct-tags nil "Select a structure tag" "structure tag") t) ; we did the completion: return t to skip other completions nil))) ; return nil to allow looking for other ways to complete (defun idlwave-structtag-reset () "Force an update of the current structure tag list upon next use." (setq idlwave-current-tags-buffer nil)) (defvar idlwave-structtag-struct-location nil "The location of the structure definition, for help display.") (defun idlwave-prepare-structure-tag-completion (var) "Find and parse the tag list for structure tag completion." ;; This works differently in source buffers and in the shell (if (eq major-mode 'idlwave-shell-mode) ;; OK, we are in the shell, do it dynamically (progn (message "preparing shell tags") ;; The following call puts the tags into `idlwave-current-struct-tags' (idlwave-complete-structure-tag-query-shell var) ;; initialize (setq idlwave-sint-structtags nil idlwave-current-tags-buffer (current-buffer) idlwave-current-tags-var var idlwave-structtag-struct-location (point) idlwave-current-struct-tags (mapcar (lambda (x) (list (idlwave-sintern-structtag x 'set))) idlwave-current-struct-tags)) (if (not idlwave-current-struct-tags) (error "Cannot complete structure tags of variable %s" var))) ;; Not the shell, so probably a source buffer. (unless (catch 'exit (save-excursion (goto-char (point-max)) ;; Find possible definitions of the structure. (while (idlwave-find-structure-definition var nil 'all) (let ((tags (idlwave-struct-tags))) (when tags ;; initialize (setq idlwave-sint-structtags nil idlwave-current-tags-buffer (current-buffer) idlwave-current-tags-var var idlwave-structtag-struct-location (point) idlwave-current-struct-tags (mapcar (lambda (x) (list (idlwave-sintern-structtag x 'set))) tags)) (throw 'exit t)))))) (error "Cannot complete structure tags of variable %s" var)))) (defun idlwave-complete-structure-tag-query-shell (var) "Ask the shell for the tags of the structure in variable or expression VAR." (idlwave-shell-send-command (format "if size(%s,/TYPE) eq 8 then print,tag_names(%s)" var var) 'idlwave-complete-structure-tag-get-tags-from-help 'hide 'wait)) (defvar idlwave-shell-prompt-pattern) (defvar idlwave-shell-command-output) (defun idlwave-complete-structure-tag-get-tags-from-help () "Filter structure tag name output, result to `idlwave-current-struct-tags'." (setq idlwave-current-struct-tags (if (string-match (concat "tag_names(.*) *\n" "\\(\\(.*[\r\n]?\\)*\\)" "\\(" idlwave-shell-prompt-pattern "\\)") idlwave-shell-command-output) (split-string (match-string 1 idlwave-shell-command-output))))) ;; Fake help in the source buffer for structure tags. ;; kwd and name are global-variables here. (defvar name) (defvar kwd) (defvar idlwave-help-do-struct-tag) (defun idlwave-complete-structure-tag-help (mode word) (cond ((eq mode 'test) ;; fontify only in source buffers, not in the shell. (not (equal idlwave-current-tags-buffer (get-buffer (idlwave-shell-buffer))))) ((eq mode 'set) (setq kwd word idlwave-help-do-struct-tag idlwave-structtag-struct-location)) (t (error "This should not happen")))) (provide 'idlw-complete-structtag) ;;; idlw-complete-structtag.el ends here ;; arch-tag: d1f9e55c-e504-4187-9c31-3c3651fa4bfa