* lisp/url/url-future.el (url-future-call): Remove useless value call.
[emacs.git] / lisp / emacs-lisp / pp.el
blobb7e553272f2304a8833c7a7ab1b1b81b8bf0c689
1 ;;; pp.el --- pretty printer for Emacs Lisp
3 ;; Copyright (C) 1989, 1993, 2001-2013 Free Software Foundation, Inc.
5 ;; Author: Randal Schwartz <merlyn@stonehenge.com>
6 ;; Keywords: lisp
8 ;; This file is part of GNU Emacs.
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 3 of the License, or
13 ;; (at your option) any later version.
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.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;;; Code:
27 (defvar font-lock-verbose)
29 (defgroup pp nil
30 "Pretty printer for Emacs Lisp."
31 :prefix "pp-"
32 :group 'lisp)
34 (defcustom pp-escape-newlines t
35 "Value of `print-escape-newlines' used by pp-* functions."
36 :type 'boolean
37 :group 'pp)
39 ;;;###autoload
40 (defun pp-to-string (object)
41 "Return a string containing the pretty-printed representation of OBJECT.
42 OBJECT can be any Lisp object. Quoting characters are used as needed
43 to make output that `read' can handle, whenever this is possible."
44 (with-temp-buffer
45 (lisp-mode-variables nil)
46 (set-syntax-table emacs-lisp-mode-syntax-table)
47 (let ((print-escape-newlines pp-escape-newlines)
48 (print-quoted t))
49 (prin1 object (current-buffer)))
50 (pp-buffer)
51 (buffer-string)))
53 ;;;###autoload
54 (defun pp-buffer ()
55 "Prettify the current buffer with printed representation of a Lisp object."
56 (goto-char (point-min))
57 (while (not (eobp))
58 ;; (message "%06d" (- (point-max) (point)))
59 (cond
60 ((ignore-errors (down-list 1) t)
61 (save-excursion
62 (backward-char 1)
63 (skip-chars-backward "'`#^")
64 (when (and (not (bobp)) (memq (char-before) '(?\s ?\t ?\n)))
65 (delete-region
66 (point)
67 (progn (skip-chars-backward " \t\n") (point)))
68 (insert "\n"))))
69 ((ignore-errors (up-list 1) t)
70 (while (looking-at-p "\\s)")
71 (forward-char 1))
72 (delete-region
73 (point)
74 (progn (skip-chars-forward " \t\n") (point)))
75 (insert ?\n))
76 (t (goto-char (point-max)))))
77 (goto-char (point-min))
78 (indent-sexp))
80 ;;;###autoload
81 (defun pp (object &optional stream)
82 "Output the pretty-printed representation of OBJECT, any Lisp object.
83 Quoting characters are printed as needed to make output that `read'
84 can handle, whenever this is possible.
85 Output stream is STREAM, or value of `standard-output' (which see)."
86 (princ (pp-to-string object) (or stream standard-output)))
88 (defun pp-display-expression (expression out-buffer-name)
89 "Prettify and display EXPRESSION in an appropriate way, depending on length.
90 If a temporary buffer is needed for representation, it will be named
91 after OUT-BUFFER-NAME."
92 (let* ((old-show-function temp-buffer-show-function)
93 ;; Use this function to display the buffer.
94 ;; This function either decides not to display it at all
95 ;; or displays it in the usual way.
96 (temp-buffer-show-function
97 (function
98 (lambda (buf)
99 (with-current-buffer buf
100 (goto-char (point-min))
101 (end-of-line 1)
102 (if (or (< (1+ (point)) (point-max))
103 (>= (- (point) (point-min)) (frame-width)))
104 (let ((temp-buffer-show-function old-show-function)
105 (old-selected (selected-window))
106 (window (display-buffer buf)))
107 (goto-char (point-min)) ; expected by some hooks ...
108 (make-frame-visible (window-frame window))
109 (unwind-protect
110 (progn
111 (select-window window)
112 (run-hooks 'temp-buffer-show-hook))
113 (when (window-live-p old-selected)
114 (select-window old-selected))
115 (message "See buffer %s." out-buffer-name)))
116 (message "%s" (buffer-substring (point-min) (point)))
117 ))))))
118 (with-output-to-temp-buffer out-buffer-name
119 (pp expression)
120 (with-current-buffer standard-output
121 (emacs-lisp-mode)
122 (setq buffer-read-only nil)
123 (set (make-local-variable 'font-lock-verbose) nil)))))
125 ;;;###autoload
126 (defun pp-eval-expression (expression)
127 "Evaluate EXPRESSION and pretty-print its value.
128 Also add the value to the front of the list in the variable `values'."
129 (interactive
130 (list (read-from-minibuffer "Eval: " nil read-expression-map t
131 'read-expression-history)))
132 (message "Evaluating...")
133 (setq values (cons (eval expression) values))
134 (pp-display-expression (car values) "*Pp Eval Output*"))
136 ;;;###autoload
137 (defun pp-macroexpand-expression (expression)
138 "Macroexpand EXPRESSION and pretty-print its value."
139 (interactive
140 (list (read-from-minibuffer "Macroexpand: " nil read-expression-map t
141 'read-expression-history)))
142 (pp-display-expression (macroexpand expression) "*Pp Macroexpand Output*"))
144 (defun pp-last-sexp ()
145 "Read sexp before point. Ignores leading comment characters."
146 (let ((stab (syntax-table)) (pt (point)) start exp)
147 (set-syntax-table emacs-lisp-mode-syntax-table)
148 (save-excursion
149 (forward-sexp -1)
150 ;; If first line is commented, ignore all leading comments:
151 (if (save-excursion (beginning-of-line) (looking-at-p "[ \t]*;"))
152 (progn
153 (setq exp (buffer-substring (point) pt))
154 (while (string-match "\n[ \t]*;+" exp start)
155 (setq start (1+ (match-beginning 0))
156 exp (concat (substring exp 0 start)
157 (substring exp (match-end 0)))))
158 (setq exp (read exp)))
159 (setq exp (read (current-buffer)))))
160 (set-syntax-table stab)
161 exp))
163 ;;;###autoload
164 (defun pp-eval-last-sexp (arg)
165 "Run `pp-eval-expression' on sexp before point.
166 With argument, pretty-print output into current buffer.
167 Ignores leading comment characters."
168 (interactive "P")
169 (if arg
170 (insert (pp-to-string (eval (pp-last-sexp))))
171 (pp-eval-expression (pp-last-sexp))))
173 ;;;###autoload
174 (defun pp-macroexpand-last-sexp (arg)
175 "Run `pp-macroexpand-expression' on sexp before point.
176 With argument, pretty-print output into current buffer.
177 Ignores leading comment characters."
178 (interactive "P")
179 (if arg
180 (insert (pp-to-string (macroexpand (pp-last-sexp))))
181 (pp-macroexpand-expression (pp-last-sexp))))
183 ;;; Test cases for quote
184 ;; (pp-eval-expression ''(quote quote))
185 ;; (pp-eval-expression ''((quote a) (quote b)))
186 ;; (pp-eval-expression ''('a 'b)) ; same as above
187 ;; (pp-eval-expression ''((quote (quote quote)) (quote quote)))
188 ;; These do not satisfy the quote test.
189 ;; (pp-eval-expression ''quote)
190 ;; (pp-eval-expression ''(quote))
191 ;; (pp-eval-expression ''(quote . quote))
192 ;; (pp-eval-expression ''(quote a b))
193 ;; (pp-eval-expression ''(quotefoo))
194 ;; (pp-eval-expression ''(a b))
196 (provide 'pp) ; so (require 'pp) works
198 ;;; pp.el ends here