lisp/chistory.el

   1 ;;; chistory.el --- list command history
   2
   3 ;; Copyright (C) 1985, 2001-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: K. Shane Hartman
   6 ;; Maintainer: emacs-devel@gnu.org
   7 ;; Keywords: convenience
   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 3 of the License, or
  14 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This really has nothing to do with list-command-history per se, but
  27 ;; its a nice alternative to C-x ESC ESC (repeat-complex-command) and
  28 ;; functions as a lister if given no pattern.  It's not important
  29 ;; enough to warrant a file of its own.
  30
  31 ;;; Code:
  32
  33 (defgroup chistory nil
  34   "List command history."
  35   :group 'keyboard)
  36
  37 ;;;###autoload
  38 (defun repeat-matching-complex-command (&optional pattern)
  39   "Edit and re-evaluate complex command with name matching PATTERN.
  40 Matching occurrences are displayed, most recent first, until you select
  41 a form for evaluation.  If PATTERN is empty (or nil), every form in the
  42 command history is offered.  The form is placed in the minibuffer for
  43 editing and the result is evaluated."
  44   (interactive "sRedo Command (regexp): ")
  45   (if pattern
  46       (if (string-match "[^ \t]" pattern)
  47           (setq pattern (substring pattern (match-beginning 0)))
  48         (setq pattern nil)))
  49   (let ((history command-history)
  50         (temp)
  51         (what))
  52     (while (and history (not what))
  53       (setq temp (car history))
  54       (if (and (or (not pattern) (string-match pattern (symbol-name (car temp))))
  55                (y-or-n-p (format "Redo %S? " temp)))
  56           (setq what (car history))
  57         (setq history (cdr history))))
  58     (if (not what)
  59         (error "Command history exhausted")
  60       ;; Try to remove any useless command history element for this command.
  61       (if (eq (car (car command-history)) 'repeat-matching-complex-command)
  62           (setq command-history (cdr command-history)))
  63       (edit-and-eval-command "Redo: " what))))
  64
  65 (defcustom default-command-history-filter-garbage
  66   '(command-history-mode
  67     list-command-history
  68     electric-command-history)
  69   "A list of symbols to be ignored by `default-command-history-filter'.
  70 If that function is given a list whose car is an element of this list,
  71 then it will return non-nil (indicating the list should be discarded from
  72 the history).
  73 Initially, all commands related to the command history are discarded."
  74   :type '(repeat symbol)
  75   :group 'chistory)
  76
  77 (defvar list-command-history-filter 'default-command-history-filter
  78   "Predicate to test which commands should be excluded from the history listing.
  79 If non-nil, should be the name of a function of one argument.
  80 It is passed each element of the command history when
  81 \\[list-command-history] is called.  If the filter returns non-nil for
  82 some element, that element is excluded from the history listing.  The
  83 default filter removes commands associated with the command-history.")
  84
  85 (defun default-command-history-filter (frob)
  86   "Filter commands matching `default-command-history-filter-garbage' list
  87 from the command history."
  88   (or (not (consp frob))
  89       (memq (car frob) default-command-history-filter-garbage)))
  90
  91 (defcustom list-command-history-max 32
  92   "If non-nil, maximum length of the listing produced by `list-command-history'."
  93   :type '(choice integer (const nil))
  94   :group 'chistory)
  95
  96 ;;;###autoload
  97 (defun list-command-history ()
  98   "List history of commands that used the minibuffer.
  99 The number of commands listed is controlled by `list-command-history-max'.
 100 Calls value of `list-command-history-filter' (if non-nil) on each history
 101 element to judge if that element should be excluded from the list.
 102
 103 The buffer is left in Command History mode."
 104   (interactive)
 105   (with-output-to-temp-buffer
 106       "*Command History*"
 107     (let ((history command-history)
 108           (buffer-read-only nil)
 109           (count (or list-command-history-max -1)))
 110       (while (and (/= count 0) history)
 111         (if (and (bound-and-true-p list-command-history-filter)
 112                  (funcall list-command-history-filter (car history)))
 113             nil
 114           (setq count (1- count))
 115           (prin1 (car history))
 116           (terpri))
 117         (setq history (cdr history))))
 118     (with-current-buffer "*Command History*"
 119       (goto-char (point-min))
 120       (if (eobp)
 121           (error "No command history")
 122         (command-history-mode)))))
 123
 124 (define-obsolete-variable-alias 'command-history-map
 125   'command-history-mode-map "24.1")
 126 (defvar command-history-mode-map
 127   (let ((map (make-sparse-keymap)))
 128     (set-keymap-parent map lisp-mode-shared-map)
 129     (suppress-keymap map)
 130     (define-key map "x" 'command-history-repeat)
 131     (define-key map "\n" 'next-line)
 132     (define-key map "\r" 'next-line)
 133     (define-key map "\177" 'previous-line)
 134     map)
 135   "Keymap for `command-history-mode'.")
 136
 137 (define-derived-mode command-history-mode fundamental-mode "Command History"
 138   "Major mode for listing and repeating recent commands.
 139
 140 Keybindings:
 141 \\{command-history-mode-map}"
 142   (lisp-mode-variables nil)
 143   (set-syntax-table emacs-lisp-mode-syntax-table)
 144   (setq buffer-read-only t))
 145
 146 (defcustom command-history-hook nil
 147   "If non-nil, its value is called on entry to `command-history-mode'."
 148   :type 'hook
 149   :group 'chistory)
 150
 151 (defun command-history-repeat ()
 152   "Repeat the command shown on the current line.
 153 The buffer for that command is the previous current buffer."
 154   (interactive)
 155   (save-excursion
 156     (eval (prog1
 157               (save-excursion
 158                 (beginning-of-line)
 159                 (read (current-buffer)))
 160             (set-buffer
 161              (car (cdr (buffer-list))))))))
 162
 163 ;;;###autoload
 164 (defun command-history ()
 165   "Examine commands from `command-history' in a buffer.
 166 The number of commands listed is controlled by `list-command-history-max'.
 167 The command history is filtered by `list-command-history-filter' if non-nil.
 168 Use \\<command-history-map>\\[command-history-repeat] to repeat the command on the current line.
 169
 170 Otherwise much like Emacs-Lisp Mode except that there is no self-insertion
 171 and digits provide prefix arguments.  Tab does not indent.
 172 \\{command-history-map}
 173
 174 This command always recompiles the Command History listing
 175 and runs the normal hook `command-history-hook'."
 176   (interactive)
 177   (list-command-history)
 178   (pop-to-buffer "*Command History*")
 179   (run-hooks 'command-history-hook))
 180
 181 (provide 'chistory)
 182
 183 ;;; chistory.el ends here