emacs/lisp/icomplete.el

;;; icomplete.el - minibuffer completion incremental feedback
;;; This package is in the publid domain.

;;; Author: Ken Manheimer <klm@nist.gov>
;;; Maintainer: Ken Manheimer <klm@nist.gov>
;;; Version: icomplete.el,v 3.2 1993/11/19 18:42:52 klm Exp klm
;;; Created: Mar 1993 klm@nist.gov - first release to usenet
;;; Keywords: help, abbrev

;;; Commentary:

;;; Loading this package implements a more finely-grained completion
;;; feedback scheme, indicating, within the minibuffer, the
;;; prospective minibuffer completion candidates, as you type.  See
;;; the documentation string for 'icomplete-prompt' for a specific
;;; description of icompletion.

;;; This will not work on Emacs 18 versions - there may be a version
;;; for v18 in the elisp archives, at archive.cis.ohio-state.edu, in
;;; /pub/gnu/emacs/elisp-archive.

;;; Code:

;;;_ + Provide
(provide 'icomplete)

;;;_ + User Customization variables
;;;_  = icomplete-inhibit
(defvar icomplete-inhibit nil
  "*Set this variable to t at any time to inhibit icomplete.")

;;;_ + Setup
;;;_  - Internal Variables
;;;_   = icomplete-eoinput 1
(defvar icomplete-eoinput 1
  "Point where minibuffer input ends and completion info begins.")
(make-variable-buffer-local 'icomplete-eoinput)
;;;_  > icomplete-prime-session ()
(defun icomplete-prime-session ()

  "Prep emacs v 19 for icompletion.  For emacs v19.18 and later revs,
icomplete is installed in 'minibuffer-setup-hook'.  Global pre- and
post-command-hook functions are used in v19.17 and earlier revs."

      (let* ((v19-rev (and (string-match "^19\\.\\([0-9]+\\)" emacs-version)
		       (string-to-int (substring emacs-version
						 (match-beginning 1)
						 (match-end 1))))))

	(cond ((and v19-rev		; emacs v 19, some rev,
		    (> v19-rev 17))
	       ;; Post v19rev17, has minibuffer-setup-hook, use it:
	       (add-hook 'minibuffer-setup-hook 'icomplete-prime-minibuffer))
	      (v19-rev
	       ;; v19rev17 and prior (including lucid): use global
	       ;; pre- and post-command-hooks, instead:
	       (add-hook 'pre-command-hook 'icomplete-pre-command-hook 'append)
	       (add-hook 'post-command-hook
			 'icomplete-post-command-hook 'append))
	      ((format "icomplete: non v19 emacs, %s - %s"
		       emacs-version "try elisp-archive icomplete")))))
;;;_  > icomplete-prime-minibuffer ()
(defun icomplete-prime-minibuffer ()

  "Prep emacs, v 19.18 or later, for icomplete.  \(icomplete-prime-
session establishes global hooks, instead, in emacs 19 versions 19.17
and prior.\)  Run via minibuffer-setup-hook \(emacs 19.18 or later\),
adds icomplete pre- and post-command hooks to do icomplete display
management."

  ;; We append the hooks because preliminary version of blink-paren
  ;; post-command-hook i have interferes with proper operation of
  ;; minibuffer quit.
  (make-local-variable 'pre-command-hook)
  (make-local-variable 'post-command-hook)
  (add-hook 'pre-command-hook 'icomplete-pre-command-hook)
  (add-hook 'post-command-hook 'icomplete-post-command-hook))
;;;_  > icomplete-window-minibuffer-p ()
(defmacro icomplete-window-minibuffer-p ()

  "Returns non-nil if current window is a minibuffer window.
Trivially equates to '(window-minibuffer-p nil)', with the nil
provided in case the argument is not optional in Lucid emacs (which
some net correspondance seems to indicate)."

  '(window-minibuffer-p nil))

;;;_ + Completion
;;;_  - Completion feedback hooks
;;;_   > icomplete-pre-command-hook ()
(defun icomplete-pre-command-hook ()
  "Cleanup completions exhibit before user's new input (or whatever) is dealt
with."
  (if (and (icomplete-window-minibuffer-p)
	   (not (symbolp minibuffer-completion-table))
	   (not icomplete-inhibit))
      (if (and (boundp 'icomplete-eoinput)
	       icomplete-eoinput)
	  (if (> icomplete-eoinput (point-max))
	      ;; Oops, got rug pulled out from under us - reinit:
	      (setq icomplete-eoinput (point-max))
	    (let ((buffer-undo-list buffer-undo-list ))	; prevent entry
	      (delete-region icomplete-eoinput (point-max))))
	(make-local-variable 'icomplete-eoinput)
	(setq icomplete-eoinput 1))))
;;;_   > icomplete-post-command-hook ()
(defun icomplete-post-command-hook ()
  "Exhibit completions, leaving icomplete-eoinput with position where user
input leaves off and exhibit begins, so icomplete-pre-command-hook can
subsequently cleanup."
  (if (and (icomplete-window-minibuffer-p)	; ... in a minibuffer.
	   (not icomplete-inhibit)	; ... not specifically inhibited.
	   ;(sit-for 0)			; ... redisplay and if there's input
					; waiting, then don't icomplete
					; (stigs suggestion) (too jumpy!)
	   ;; Inhibit for file-name and other custom-func completions:
	   (not (symbolp minibuffer-completion-table))
	   )
      (let ((buffer-undo-list buffer-undo-list ))	; prevent entry
	(icomplete-exhibit))))
;;;_   > icomplete-window-setup-hook ()
(defun icomplete-window-setup-hook ()
  "Exhibit completions, leaving icomplete-eoinput with position where user
input leaves off and exhibit begins, so icomplete-pre-command-hook can
subsequently cleanup."
  (if (and (icomplete-window-minibuffer-p)	; ... in a minibuffer.
	   )
      (message "ic ws doing")(sit-for 1)))
;;;_   > icomplete-exhibit ()
(defun icomplete-exhibit ()
  "Exhibit completions, leaving icomplete-eoinput with position where user
input leaves off and exhibit begins, so icomplete-pre-command-hook can
subsequently cleanup."
  (if (not (symbolp minibuffer-completion-table))
      (let ((contents (buffer-substring (point-min)(point-max)))
	    (buffer-undo-list t))
	(save-excursion
	  (goto-char (point-max))
                                        ; Register the end of input, so we
                                        ; know where the extra stuff
                                        ; (match-status info) begins:
	  (if (not (boundp 'icomplete-eoinput))
	      ;; In case it got wiped out by major mode business:
	      (make-local-variable 'icomplete-eoinput))
	  (setq icomplete-eoinput (point))
                                        ; Insert the match-status information:
	  (if (> (point-max) 1)
	      (insert-string
		(icomplete-prompt contents
				  minibuffer-completion-table
				  minibuffer-completion-predicate
				  (not
				   minibuffer-completion-confirm))))))))

;;;_  - Completion feedback producer
;;;_   > icomplete-prompt (name candidates predicate require-match)
(defun icomplete-prompt (name candidates predicate require-match)
  "Identify prospective candidates for minibuffer completion.

The display is updated with each minibuffer keystroke when icomplete
is enabled \(by loading the 'icomplete' elisp package\) and doing
minibuffer completion.

Prospective completion suffixes (if any) are displayed, bracketed by
one of \(), \[], or \{} pairs.  The choice of brackets is as follows:

  \(...) - a single prospect is identified and matching is enforced,
  \[...] - a single prospect is identified but matching is optional, or
  \{...} - multiple prospects, separated by commas, are indicated, and
          further input is required to distingish a single one.

The displays for disambiguous matches have \" [Matched]\" appended
\(whether complete or not), or \" \[No matches]\", if no eligible
matches exist."

  (let ((comps (all-completions name candidates predicate))
                                        ; "-determined" - only one candidate
        (open-bracket-determined (if require-match "(" "["))
        (close-bracket-determined (if require-match ")" "]"))
                                        ;"-prospects" - more than one candidate
        (open-bracket-prospects "{")
        (close-bracket-prospects "}")
        )
    (cond ((null comps) (format " %sNo matches%s"
                                open-bracket-determined
                                close-bracket-determined))
          ((null (cdr comps))           ;one match
           (concat (if (and (> (length (car comps))
                               (length name)))
                       (concat open-bracket-determined
                               (substring (car comps) (length name))
                               close-bracket-determined)
                     "")
                   " [Matched]"))
          (t                            ;multiple matches
           (let* ((most (try-completion name candidates predicate))
                  (most-len (length most))
                  most-is-exact
                  (alternatives
                   (apply
                    'concat
                    (cdr (apply 'append
                                (mapcar '(lambda (com)
                                           (if (= (length com) most-len)
                                               ;; Most is one exact match,
                                               ;; note that and leave out
                                               ;; for later indication:
                                               (progn
                                                 (setq most-is-exact t)
                                                 ())
                                             (list ","
                                                   (substring com
                                                              most-len))))
                                        comps))))))
             (concat (and (> most-len (length name))
                          (concat open-bracket-determined
                                  (substring most (length name))
                                  close-bracket-determined))
                     open-bracket-prospects
                     (if most-is-exact
                         (concat "," alternatives)
                       alternatives)
                     close-bracket-prospects))))))

;;;_ + Initialization
(icomplete-prime-session)

;;;_* Local emacs vars.
'(
Local variables:
eval: (save-excursion
        (if (not (condition-case err (outline-mode t)
                   (wrong-number-of-arguments nil)))
            (progn
              (message
               "Allout outline-mode not loaded, not adjusting buffer exposure")
              (sit-for 1))
          (message "Adjusting '%s' visibility" (buffer-name))
          (outline-lead-with-comment-string ";;;_")
          (goto-char 0)
          (outline-exposure -1 0)))
End:)

;;; icomplete.el ends here