Use completion-at-point rather than completion-in-region.

* lisp/wid-edit.el: Use lexical scoping and move towards completion-at-point.
(widget-complete): Use new :completion-function property.
(widget-completions-at-point): New function.
(default): Use :completion-function instead of :complete.
(widget-default-completions): Rename from widget-default-complete, rewrite.
(widget-string-complete, widget-file-complete, widget-color-complete):
Remove functions.
(file, symbol, function, variable, coding-system, color):
* lisp/international/mule-cmds.el (default-input-method, charset)
(language-info-custom-alist):
* lisp/cus-edit.el (face): Use new property :completions.

* lisp/progmodes/pascal.el (pascal-completions-at-point): New function.
(pascal-mode): Use it.
(pascal-mode-map): Use completion-at-point.
(pascal-toggle-completions): Make obsolete.
(pascal-complete-word, pascal-show-completions):
* lisp/progmodes/octave-mod.el (octave-complete-symbol):
Redefine as obsolete alias.
* lisp/progmodes/octave-inf.el (inferior-octave-completion-at-point):
Signal absence of completion info for old Octave,
(inferior-octave-complete): Redefine as obsolete alias.
* lisp/progmodes/meta-mode.el: Use lexical-binding and completion-at-point.
(meta-completions-at-point): Rename from meta-complete-symbol and
adapt it for use on completion-at-point-functions.
(meta-common-mode): Use it.
(meta-looking-at-backward, meta-match-buffer): Remove.
(meta-complete-symbol): Redefine as obsolete alias.
(meta-common-mode-map): Use completion-at-point.
* lisp/progmodes/make-mode.el: Use lexical-binding and completion-at-point.
(makefile-mode-map): Use completion-at-point.
(makefile-completions-at-point): Rename from makefile-complete and
adapt it for use on completion-at-point-functions.
(makefile-mode): Use it.
(makefile-complete): Redefine as obsolete alias.

5 files changed, 71 insertions, 131 deletions

diff --git a/lisp/progmodes/make-mode.el b/lisp/progmodes/make-mode.el
index 22e5d2f7c5c..293ba49d4ae 100644
--- a/lisp/progmodes/make-mode.el
+++ b/lisp/progmodes/make-mode.el
@@ -1,4 +1,4 @@
-;;; make-mode.el --- makefile editing commands for Emacs
+;;; make-mode.el --- makefile editing commands for Emacs -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1992, 1994, 1999-2011  Free Software Foundation, Inc.
 
@@ -602,7 +602,7 @@ The function must satisfy this calling convention:
     (define-key map "\C-c\C-m\C-p" 'makefile-makepp-mode)
     (define-key map "\M-p"     'makefile-previous-dependency)
     (define-key map "\M-n"     'makefile-next-dependency)
-    (define-key map "\e\t"     'makefile-complete)
+    (define-key map "\e\t"     'completion-at-point)
 
     ;; Make menus.
     (define-key map [menu-bar makefile-mode]
@@ -653,7 +653,7 @@ The function must satisfy this calling convention:
       '(menu-item "Find Targets and Macros" makefile-pickup-everything
                   :help "Notice names of all macros and targets in Makefile"))
     (define-key map [menu-bar makefile-mode complete]
-      '(menu-item "Complete Target or Macro" makefile-complete
+      '(menu-item "Complete Target or Macro" completion-at-point
                   :help "Perform completion on Makefile construct preceding point"))
     (define-key map [menu-bar makefile-mode backslash]
       '(menu-item "Backslash Region" makefile-backslash-region
@@ -852,6 +852,8 @@ Makefile mode can be configured by modifying the following variables:
    List of special targets. You will be offered to complete
    on one of those in the minibuffer whenever you enter a `.'.
    at the beginning of a line in Makefile mode."
+  (add-hook 'completion-at-point-functions
+            #'makefile-completions-at-point nil t)
   (add-hook 'write-file-functions
             'makefile-warn-suspicious-lines nil t)
   (add-hook 'write-file-functions
@@ -1147,11 +1149,7 @@ and adds all qualifying names to the list of known targets."
 
 ;;; Completion.
 
-(defun makefile-complete ()
-  "Perform completion on Makefile construct preceding point.
-Can complete variable and target names.
-The context determines which are considered."
-  (interactive)
+(defun makefile-completions-at-point ()
   (let* ((beg (save-excursion
                 (skip-chars-backward "^$(){}:#= \t\n")
                 (point)))
@@ -1168,22 +1166,26 @@ The context determines which are considered."
                ;; Preceding "$(" or "${" means macros only.
                ((and (memq pc '(?\{ ?\())
                      (progn
-                       (setq paren (if (eq paren ?\{) ?\} ?\)))
+                       (setq paren (if (eq pc ?\{) ?\} ?\)))
                        (backward-char)
                        (= (preceding-char) ?$)))
                 t)))))
-
-         (table (apply-partially 'completion-table-with-terminator
-                                   (cond
-                                    (do-macros (or paren ""))
-                                    ((save-excursion (goto-char beg) (bolp)) ":")
-                                    (t " "))
-                                   (append (if do-macros
-                                               '()
-                                             makefile-target-table)
-                                           makefile-macro-table))))
-    (completion-in-region beg (point) table)))
-
+         (suffix (cond
+                  (do-macros (if paren (string paren)))
+                  ((save-excursion (goto-char beg) (bolp)) ":")
+                  (t " "))))
+    (list beg (point)
+          (append (if do-macros '() makefile-target-table)
+                  makefile-macro-table)
+          :exit-function
+          (if suffix
+              (lambda (_s finished)
+                (when (memq finished '(sole finished))
+                  (if (looking-at (regexp-quote suffix))
+                      (goto-char (match-end 0))
+                    (insert suffix))))))))
+
+(define-obsolete-function-alias 'makefile-complete 'completion-at-point "24.1")
 
 
 ;; Backslashification.  Stolen from cc-mode.el.
diff --git a/lisp/progmodes/meta-mode.el b/lisp/progmodes/meta-mode.el
index b36104bf49b..ab640c0e270 100644
--- a/lisp/progmodes/meta-mode.el
+++ b/lisp/progmodes/meta-mode.el
@@ -1,4 +1,4 @@
-;;; meta-mode.el --- major mode for editing Metafont or MetaPost sources
+;;; meta-mode.el --- major mode for editing Metafont or MetaPost sources -*- lexical-binding:t -*-
 
 ;; Copyright (C) 1997, 2001-2011  Free Software Foundation, Inc.
 
@@ -471,16 +471,13 @@ If the list was changed, sort the list and remove duplicates first."
   (string-lessp (car a) (car b)))
 
 
-(defun meta-complete-symbol ()
-  "Perform completion on Metafont or MetaPost symbol preceding point."
-  ;; FIXME: Use completion-at-point-functions.
-  (interactive "*")
+(defun meta-completions-at-point ()
   (let ((list meta-complete-list)
         entry)
     (while list
       (setq entry (car list)
             list (cdr list))
-      (if (meta-looking-at-backward (car entry) 200)
+      (if (looking-back (car entry) (max (point-min) (- (point) 200)))
           (setq list nil)))
     (if (numberp (nth 1 entry))
         (let* ((sub (nth 1 entry))
@@ -488,31 +485,19 @@ If the list was changed, sort the list and remove duplicates first."
                (begin (match-beginning sub))
                (end (match-end sub))
                (list (funcall (nth 2 entry))))
-          (completion-in-region
-           begin end
-           (if (zerop (length close)) list
-             (apply-partially 'completion-table-with-terminator
-                              close list))))
-      (funcall (nth 1 entry)))))
-
-
-(defun meta-looking-at-backward (regexp &optional limit)
-  ;; utility function used in `meta-complete-symbol'
-  (let ((pos (point)))
-    (save-excursion
-      (and (re-search-backward
-            regexp (if limit (max (point-min) (- (point) limit))) t)
-           (eq (match-end 0) pos)))))
-
-(defun meta-match-buffer (n)
-  ;; utility function used in `meta-complete-symbol'
-  (if (match-beginning n)
-      (let ((str (buffer-substring (match-beginning n) (match-end n))))
-        (set-text-properties 0 (length str) nil str)
-        (copy-sequence str))
-    ""))
-
-
+          (list
+           begin end list
+           :exit-function
+           (unless (zerop (length close))
+             (lambda (_s finished)
+               (when (memq finished '(sole finished))
+                 (if (looking-at (regexp-quote close))
+                     (goto-char (match-end 0))
+                   (insert close)))))))
+      (nth 1 entry))))
+
+(define-obsolete-function-alias 'meta-complete-symbol
+  'completion-at-point "24.1")
 
 ;;; Indentation.
 
@@ -906,7 +891,7 @@ The environment marked is the one that contains point or follows point."
     (define-key map "\C-c;"     'meta-comment-region)
     (define-key map "\C-c:"     'meta-uncomment-region)
     ;; Symbol Completion:
-    (define-key map "\M-\t"     'meta-complete-symbol)
+    (define-key map "\M-\t"     'completion-at-point)
     ;; Shell Commands:
     ;; (define-key map "\C-c\C-c"  'meta-command-file)
     ;; (define-key map "\C-c\C-k"  'meta-kill-job)
@@ -935,7 +920,7 @@ The environment marked is the one that contains point or follows point."
        ["Uncomment Region"              meta-uncomment-region
         :active (meta-mark-active)]
        "--"
-       ["Complete Symbol"               meta-complete-symbol t]
+       ["Complete Symbol"               completion-at-point t]
 ;      "--"
 ;      ["Command on Buffer"             meta-command-file t]
 ;      ["Kill Job"                      meta-kill-job t]
@@ -994,6 +979,7 @@ The environment marked is the one that contains point or follows point."
 
   (set (make-local-variable 'parse-sexp-ignore-comments) t)
 
+  (add-hook 'completion-at-point-functions #'meta-completions-at-point nil t)
   (set (make-local-variable 'comment-indent-function) #'meta-comment-indent)
   (set (make-local-variable 'indent-line-function) #'meta-indent-line)
   ;; No need to define a mode-specific 'indent-region-function.
diff --git a/lisp/progmodes/octave-inf.el b/lisp/progmodes/octave-inf.el
index 803a542563c..cb64b2436c6 100644
--- a/lisp/progmodes/octave-inf.el
+++ b/lisp/progmodes/octave-inf.el
@@ -267,8 +267,12 @@ startup file, `~/.emacs-octave'."
           (save-excursion
             (skip-syntax-backward "w_" (comint-line-beginning-position))
             (point))))
-    (cond (inferior-octave-complete-impossible nil)
-          ((eq start end) nil)
+    (cond ((eq start end) nil)
+          (inferior-octave-complete-impossible
+           (message (concat
+                     "Your Octave does not have `completion_matches'.  "
+                     "Please upgrade to version 2.X."))
+           nil)
           (t
            (list
             start end
@@ -279,19 +283,8 @@ startup file, `~/.emacs-octave'."
                (sort (delete-dups inferior-octave-output-list)
                      'string-lessp))))))))
 
-(defun inferior-octave-complete ()
-  "Perform completion on the Octave symbol preceding point.
-This is implemented using the Octave command `completion_matches' which
-is NOT available with versions of Octave prior to 2.0."
-  (interactive)
-  (if inferior-octave-complete-impossible
-      (error (concat
-              "Your Octave does not have `completion_matches'.  "
-              "Please upgrade to version 2.X."))
-    (let ((data (inferior-octave-completion-at-point)))
-      (if (null data)
-          (message "Cannot complete an empty string")
-        (apply #'completion-in-region data)))))
+(define-obsolete-function-alias 'inferior-octave-complete
+  'completion-at-point "24.1")
 
 (defun inferior-octave-dynamic-list-input-ring ()
   "List the buffer's input history in a help buffer."
diff --git a/lisp/progmodes/octave-mod.el b/lisp/progmodes/octave-mod.el
index 39d997e1d5e..183347cdeca 100644
--- a/lisp/progmodes/octave-mod.el
+++ b/lisp/progmodes/octave-mod.el
@@ -983,12 +983,8 @@ otherwise."
                         (setq end (point))))
     (list beg end octave-completion-alist)))
 
-(defun octave-complete-symbol ()
-  "Perform completion on Octave symbol preceding point.
-Compare that symbol against Octave's reserved words and builtin
-variables."
-  (interactive)
-  (apply 'completion-in-region (octave-completion-at-point-function)))
+(define-obsolete-function-alias 'octave-complete-symbol
+  'completion-at-point "24.1")
 
 ;;; Electric characters && friends
 
diff --git a/lisp/progmodes/pascal.el b/lisp/progmodes/pascal.el
index e28bb14bb9a..57ed13969b4 100644
--- a/lisp/progmodes/pascal.el
+++ b/lisp/progmodes/pascal.el
@@ -40,7 +40,6 @@
 ;;       pascal-tab-always-indent  t
 ;;       pascal-auto-endcomments   t
 ;;       pascal-auto-lineup        '(all)
-;;       pascal-toggle-completions nil
 ;;       pascal-type-keywords      '("array" "file" "packed" "char"
 ;;                                   "integer" "real" "string" "record")
 ;;       pascal-start-keywords     '("begin" "end" "function" "procedure"
@@ -79,8 +78,8 @@
     ;; These are user preferences, so not to set by default.
     ;;(define-key map "\r"       'electric-pascal-terminate-line)
     ;;(define-key map "\t"       'electric-pascal-tab)
-    (define-key map "\M-\t"    'pascal-complete-word)
-    (define-key map "\M-?"     'pascal-show-completions)
+    (define-key map "\M-\t"    'completion-at-point)
+    (define-key map "\M-?"     'completion-help-at-point)
     (define-key map "\177"     'backward-delete-char-untabify)
     (define-key map "\M-\C-h"  'pascal-mark-defun)
     (define-key map "\C-c\C-b" 'pascal-insert-block)
@@ -232,13 +231,13 @@ will do all lineups."
               (const :tag "Case statements" case))
   :group 'pascal)
 
-(defcustom pascal-toggle-completions nil
-  "*Non-nil means \\<pascal-mode-map>\\[pascal-complete-word] should try all possible completions one by one.
-Repeated use of \\[pascal-complete-word] will show you all of them.
+(defvar pascal-toggle-completions nil
+  "*Non-nil meant \\<pascal-mode-map>\\[pascal-complete-word] would try all possible completions one by one.
+Repeated use of \\[pascal-complete-word] would show you all of them.
 Normally, when there is more than one possible completion,
-it displays a list of all possible completions."
-  :type 'boolean
-  :group 'pascal)
+it displays a list of all possible completions.")
+(make-obsolete-variable 'pascal-toggle-completions
+                        'completion-cycle-threshold "24.1")
 
 (defcustom pascal-type-keywords
   '("array" "file" "packed" "char" "integer" "real" "string" "record")
@@ -303,9 +302,9 @@ are handled in another way, and should not be added to this list."
   "Major mode for editing Pascal code. \\<pascal-mode-map>
 TAB indents for Pascal code.  Delete converts tabs to spaces as it moves back.
 
-\\[pascal-complete-word] completes the word around current point with respect \
+\\[completion-at-point] completes the word around current point with respect \
 to position in code
-\\[pascal-show-completions] shows all possible completions at this point.
+\\[completion-help-at-point] shows all possible completions at this point.
 
 Other useful functions are:
 
@@ -354,6 +353,7 @@ no args, if that value is non-nil."
   (set (make-local-variable 'comment-start) "{")
   (set (make-local-variable 'comment-start-skip) "(\\*+ *\\|{ *")
   (set (make-local-variable 'comment-end) "}")
+  (add-hook 'completion-at-point-functions 'pascal-completions-at-point nil t)
   ;; Font lock support
   (set (make-local-variable 'font-lock-defaults)
        '(pascal-font-lock-keywords nil t))
@@ -1287,54 +1287,17 @@ indent of the current line in parameterlist."
 (defvar pascal-last-word-shown nil)
 (defvar pascal-last-completions nil)
 
-(defun pascal-complete-word ()
-  "Complete word at current point.
-\(See also `pascal-toggle-completions', `pascal-type-keywords',
-`pascal-start-keywords' and `pascal-separator-keywords'.)"
-  (interactive)
+(defun pascal-completions-at-point ()
   (let* ((b (save-excursion (skip-chars-backward "a-zA-Z0-9_") (point)))
          (e (save-excursion (skip-chars-forward "a-zA-Z0-9_") (point))))
+    (when (> e b)
+      (list b e #'pascal-completion))))
 
-    ;; Toggle-completions inserts whole labels
-    (if pascal-toggle-completions
-        (let* ((pascal-str (buffer-substring b e))
-               (allcomp (if (and pascal-toggle-completions
-                                 (string= pascal-last-word-shown pascal-str))
-                            pascal-last-completions
-                          (all-completions pascal-str 'pascal-completion))))
-          ;; Update entry number in list
-          (setq pascal-last-completions allcomp
-                pascal-last-word-numb
-                (if (>= pascal-last-word-numb (1- (length allcomp)))
-                    0
-                  (1+ pascal-last-word-numb)))
-          (setq pascal-last-word-shown (elt allcomp pascal-last-word-numb))
-          ;; Display next match or same string if no match was found
-          (if allcomp
-              (progn
-                (goto-char e)
-                (insert-before-markers pascal-last-word-shown)
-                (delete-region b e))
-            (message "(No match)")))
-      ;; The other form of completion does not necessarily do that.
-      (completion-in-region b e 'pascal-completion))))
-
-(defun pascal-show-completions ()
-  "Show all possible completions at current point."
-  (interactive)
-  (let* ((b (save-excursion (skip-chars-backward "a-zA-Z0-9_") (point)))
-         (e (save-excursion (skip-chars-forward "a-zA-Z0-9_") (point)))
-         (pascal-str (buffer-substring b e))
-         (allcomp (if (and pascal-toggle-completions
-                           (string= pascal-last-word-shown pascal-str))
-                      pascal-last-completions
-                    (all-completions pascal-str 'pascal-completion))))
-    ;; Show possible completions in a temporary buffer.
-    (with-output-to-temp-buffer "*Completions*"
-      (display-completion-list allcomp pascal-str))
-    ;; Wait for a keypress. Then delete *Completion*  window
-    (momentary-string-display "" (point))
-    (delete-window (get-buffer-window (get-buffer "*Completions*")))))
+(define-obsolete-function-alias 'pascal-complete-word
+  'completion-at-point "24.1")
+
+(define-obsolete-function-alias 'pascal-show-completions
+  'completion-help-at-point "24.1")
 
 
 (defun pascal-get-default-symbol ()