1;;; eval-reg.el --- Redefine eval-region, and subrs that use it, in Lisp 2 3;; Copyright (C) 1994 Daniel LaLiberte 4 5;; Author: Daniel LaLiberte <liberte@cs.uiuc.edu> 6;; Keywords: lisp 7 8;; This file is part of GNU Emacs. 9 10;; GNU Emacs is free software; you can redistribute it and/or modify 11;; it under the terms of the GNU General Public License as published by 12;; the Free Software Foundation; either version 2, or (at your option) 13;; any later version. 14 15;; GNU Emacs is distributed in the hope that it will be useful, 16;; but WITHOUT ANY WARRANTY; without even the implied warranty of 17;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18;; GNU General Public License for more details. 19 20;; You should have received a copy of the GNU General Public License 21;; along with GNU Emacs; see the file COPYING. If not, write to 22;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 23 24;;;; Commentary: 25 26;;; eval-region, eval-buffer, and eval-current-buffer are redefined in 27;;; Lisp to allow customizations by Lisp code. eval-region calls 28;;; `read', `eval', and `prin1', so Lisp replacements of these 29;;; functions will affect eval-region and anything else that calls it. 30;;; eval-buffer and eval-current-buffer are redefined in Lisp to call 31;;; eval-region on the buffer. 32 33;;; Because of dynamic binding, all local variables are protected from 34;;; being seen by eval by giving them funky names. But variables in 35;;; routines that call eval-region are similarly exposed. 36 37;;; Perhaps this should be one of several files in an `elisp' package 38;;; that replaces Emacs Lisp subroutines with Lisp versions of the 39;;; same. 40 41;;; Eval-region may be installed, after loading, by calling: 42;;; (elisp-eval-region-install). Installation can be undone with: 43;;; (elisp-eval-region-uninstall). 44 45'(defpackage "elisp-eval-region" 46 (:nicknames "elisp") 47 (:use "elisp") 48 (:export 49 elisp-eval-region-install 50 elisp-eval-region-uninstall 51 elisp-eval-region-level 52 with-elisp-eval-region 53 eval-region 54 eval-buffer 55 eval-current-buffer 56 )) 57'(in-package elisp-eval-region) 58 59;; Save standard versions. 60(if (not (fboundp 'original-eval-region)) 61 (defalias 'original-eval-region (symbol-function 'eval-region))) 62(if (not (fboundp 'original-eval-buffer)) 63 (defalias 'original-eval-buffer 64 (if (fboundp 'eval-buffer) ;; only in Emacs 19 65 (symbol-function 'eval-buffer) 66 'undefined))) 67(if (not (fboundp 'original-eval-current-buffer)) 68 (defalias 'original-eval-current-buffer 69 (symbol-function 'eval-current-buffer))) 70 71(defvar elisp-eval-region-level 0 72 "If the value is 0, use the original version of `elisp-eval-region'. 73Callers of `elisp-eval-region' should increment `elisp-eval-region-level' 74while the Lisp version should be used. Installing `elisp-eval-region' 75increments it once, and uninstalling decrements it.") 76 77;; Installing and uninstalling should always be used in pairs, 78;; or just install once and never uninstall. 79(defun elisp-eval-region-install () 80 (interactive) 81 (defalias 'eval-region 'elisp-eval-region) 82 (defalias 'eval-buffer 'elisp-eval-buffer) 83 (defalias 'eval-current-buffer 'elisp-eval-current-buffer) 84 (setq elisp-eval-region-level (1+ elisp-eval-region-level))) 85 86(defun elisp-eval-region-uninstall () 87 (interactive) 88 (if (> 1 elisp-eval-region-level) 89 (setq elisp-eval-region-level (1- elisp-eval-region-level)) 90 (setq elisp-eval-region-level 0) 91 (defalias 'eval-region (symbol-function 'original-eval-region)) 92 (defalias 'eval-buffer (symbol-function 'original-eval-buffer)) 93 (defalias 'eval-current-buffer 94 (symbol-function 'original-eval-current-buffer)) 95 )) 96 97(put 'with-elisp-eval-region 'lisp-indent-function 1) 98(put 'with-elisp-eval-region 'lisp-indent-hook 1) 99(put 'with-elisp-eval-region 'edebug-form-spec t) 100 101(defmacro with-elisp-eval-region (flag &rest body) 102 "If FLAG is nil, decrement `eval-region-level' while executing BODY. 103The effect of decrementing all the way to zero is that `eval-region' 104will use the original `eval-region', which may be the Emacs subr or some 105previous redefinition. Before calling this macro, this package should 106already have been installed, using `elisp-eval-region-install', which 107increments the count once. So if another package still requires the 108Lisp version of the code, the count will still be non-zero. 109 110The count is not bound locally by this macro, so changes by BODY to 111its value will not be lost." 112 (` (let ((elisp-code (function (lambda () (,@ body))))) 113 (if (not (, flag)) 114 (unwind-protect 115 (progn 116 (setq elisp-eval-region-level (1- elisp-eval-region-level)) 117 (funcall elisp-code)) 118 (setq elisp-eval-region-level (1+ elisp-eval-region-level))) 119 (funcall elisp-code))))) 120 121 122(defun elisp-eval-region (elisp-start elisp-end &optional elisp-output) 123 "Execute the region as Lisp code. 124When called from programs, expects two arguments, 125giving starting and ending indices in the current buffer 126of the text to be executed. 127Programs can pass third argument PRINTFLAG which controls printing of output: 128nil means discard it; anything else is stream for print. 129 130This version, from `eval-reg.el', allows Lisp customization of read, 131eval, and the printer." 132 133 ;; Because this doesnt narrow to the region, one other difference 134 ;; concerns inserting whitespace after the expression being evaluated. 135 136 (interactive "r") 137 (if (= 0 elisp-eval-region-level) 138 (original-eval-region elisp-start elisp-end elisp-output) 139 (let ((elisp-pnt (point)) 140 (elisp-buf (current-buffer));; Outside buffer 141 (elisp-inside-buf (current-buffer));; Buffer current while evaling 142 ;; Mark the end because it may move. 143 (elisp-end-marker (set-marker (make-marker) elisp-end)) 144 elisp-form 145 elisp-val) 146 (goto-char elisp-start) 147 (elisp-skip-whitespace) 148 (while (< (point) elisp-end-marker) 149 (setq elisp-form (read elisp-buf)) 150 151 (let ((elisp-current-buffer (current-buffer))) 152 ;; Restore the inside current-buffer. 153 (set-buffer elisp-inside-buf) 154 (setq elisp-val (eval elisp-form)) 155 ;; Remember current buffer for next time. 156 (setq elisp-inside-buf (current-buffer)) 157 ;; Should this be protected? 158 (set-buffer elisp-current-buffer)) 159 160 (if elisp-output 161 (let ((standard-output (or elisp-output t))) 162 (setq values (cons elisp-val values)) 163 (if (eq standard-output t) 164 (prin1 elisp-val) 165 (princ "\n") 166 (prin1 elisp-val) 167 (princ "\n") 168 ))) 169 (goto-char (min (max elisp-end-marker (point)) 170 (progn (elisp-skip-whitespace) (point)))) 171 ) ; while 172 (if elisp-output nil 173 ;; like save-excursion recovery, but done only if no error occurs 174 ;; but mark is not restored 175 (set-buffer elisp-buf) 176 (goto-char elisp-pnt)) 177 nil))) 178 179 180(defun elisp-skip-whitespace () 181 ;; Leave point before the next token, skipping white space and comments. 182 (skip-chars-forward " \t\r\n\f") 183 (while (= (following-char) ?\;) 184 (skip-chars-forward "^\n\r") ; skip the comment 185 (skip-chars-forward " \t\r\n\f"))) 186 187 188(defun elisp-eval-current-buffer (&optional elisp-output) 189 "Execute the current buffer as Lisp code. 190Programs can pass argument PRINTFLAG which controls printing of output: 191nil means discard it; anything else is stream for print. 192 193This version calls `eval-region' on the whole buffer." 194 ;; The standard eval-current-buffer doesn't use eval-region. 195 (interactive) 196 (eval-region (point-min) (point-max) elisp-output)) 197 198 199(defun elisp-eval-buffer (&optional elisp-bufname elisp-printflag) 200 "Execute BUFFER as Lisp code. Use current buffer if BUFFER is nil. 201Programs can pass argument PRINTFLAG which controls printing of 202output: nil means discard it; anything else is stream for print. 203 204This version calls `eval-region' on the whole buffer." 205 (interactive) 206 (if (null elisp-bufname) 207 (setq elisp-bufname (current-buffer))) 208 (save-excursion 209 (set-buffer (or (get-buffer elisp-bufname) 210 (error "No such buffer: %s" elisp-bufname))) 211 (eval-region (point-min) (point-max) elisp-printflag))) 212 213 214(provide 'eval-reg) 215 216