Line data Source code
1 : ;;; pp.el --- pretty printer for Emacs Lisp -*- lexical-binding: t -*-
2 :
3 : ;; Copyright (C) 1989, 1993, 2001-2017 Free Software Foundation, Inc.
4 :
5 : ;; Author: Randal Schwartz <merlyn@stonehenge.com>
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 3 of the License, or
13 : ;; (at your option) 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. If not, see <http://www.gnu.org/licenses/>.
22 :
23 : ;;; Commentary:
24 :
25 : ;;; Code:
26 :
27 : (defvar font-lock-verbose)
28 :
29 : (defgroup pp nil
30 : "Pretty printer for Emacs Lisp."
31 : :prefix "pp-"
32 : :group 'lisp)
33 :
34 : (defcustom pp-escape-newlines t
35 : "Value of `print-escape-newlines' used by pp-* functions."
36 : :type 'boolean
37 : :group 'pp)
38 :
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 0 : (with-temp-buffer
45 0 : (lisp-mode-variables nil)
46 0 : (set-syntax-table emacs-lisp-mode-syntax-table)
47 0 : (let ((print-escape-newlines pp-escape-newlines)
48 : (print-quoted t))
49 0 : (prin1 object (current-buffer)))
50 0 : (pp-buffer)
51 0 : (buffer-string)))
52 :
53 : ;;;###autoload
54 : (defun pp-buffer ()
55 : "Prettify the current buffer with printed representation of a Lisp object."
56 0 : (goto-char (point-min))
57 0 : (while (not (eobp))
58 : ;; (message "%06d" (- (point-max) (point)))
59 0 : (cond
60 0 : ((ignore-errors (down-list 1) t)
61 0 : (save-excursion
62 0 : (backward-char 1)
63 0 : (skip-chars-backward "'`#^")
64 0 : (when (and (not (bobp)) (memq (char-before) '(?\s ?\t ?\n)))
65 0 : (delete-region
66 0 : (point)
67 0 : (progn (skip-chars-backward " \t\n") (point)))
68 0 : (insert "\n"))))
69 0 : ((ignore-errors (up-list 1) t)
70 0 : (skip-syntax-forward ")")
71 0 : (delete-region
72 0 : (point)
73 0 : (progn (skip-chars-forward " \t\n") (point)))
74 0 : (insert ?\n))
75 0 : (t (goto-char (point-max)))))
76 0 : (goto-char (point-min))
77 0 : (indent-sexp))
78 :
79 : ;;;###autoload
80 : (defun pp (object &optional stream)
81 : "Output the pretty-printed representation of OBJECT, any Lisp object.
82 : Quoting characters are printed as needed to make output that `read'
83 : can handle, whenever this is possible.
84 : Output stream is STREAM, or value of `standard-output' (which see)."
85 0 : (princ (pp-to-string object) (or stream standard-output)))
86 :
87 : (defun pp-display-expression (expression out-buffer-name)
88 : "Prettify and display EXPRESSION in an appropriate way, depending on length.
89 : If a temporary buffer is needed for representation, it will be named
90 : after OUT-BUFFER-NAME."
91 0 : (let* ((old-show-function temp-buffer-show-function)
92 : ;; Use this function to display the buffer.
93 : ;; This function either decides not to display it at all
94 : ;; or displays it in the usual way.
95 : (temp-buffer-show-function
96 0 : (function
97 : (lambda (buf)
98 0 : (with-current-buffer buf
99 0 : (goto-char (point-min))
100 0 : (end-of-line 1)
101 0 : (if (or (< (1+ (point)) (point-max))
102 0 : (>= (- (point) (point-min)) (frame-width)))
103 0 : (let ((temp-buffer-show-function old-show-function)
104 0 : (old-selected (selected-window))
105 0 : (window (display-buffer buf)))
106 0 : (goto-char (point-min)) ; expected by some hooks ...
107 0 : (make-frame-visible (window-frame window))
108 0 : (unwind-protect
109 0 : (progn
110 0 : (select-window window)
111 0 : (run-hooks 'temp-buffer-show-hook))
112 0 : (when (window-live-p old-selected)
113 0 : (select-window old-selected))
114 0 : (message "See buffer %s." out-buffer-name)))
115 0 : (message "%s" (buffer-substring (point-min) (point)))
116 0 : ))))))
117 0 : (with-output-to-temp-buffer out-buffer-name
118 0 : (pp expression)
119 0 : (with-current-buffer standard-output
120 0 : (emacs-lisp-mode)
121 0 : (setq buffer-read-only nil)
122 0 : (set (make-local-variable 'font-lock-verbose) nil)))))
123 :
124 : ;;;###autoload
125 : (defun pp-eval-expression (expression)
126 : "Evaluate EXPRESSION and pretty-print its value.
127 : Also add the value to the front of the list in the variable `values'."
128 : (interactive
129 0 : (list (read--expression "Eval: ")))
130 0 : (message "Evaluating...")
131 0 : (push (eval expression lexical-binding) values)
132 0 : (pp-display-expression (car values) "*Pp Eval Output*"))
133 :
134 : ;;;###autoload
135 : (defun pp-macroexpand-expression (expression)
136 : "Macroexpand EXPRESSION and pretty-print its value."
137 : (interactive
138 0 : (list (read--expression "Macroexpand: ")))
139 0 : (pp-display-expression (macroexpand-1 expression) "*Pp Macroexpand Output*"))
140 :
141 : (defun pp-last-sexp ()
142 : "Read sexp before point. Ignores leading comment characters."
143 0 : (with-syntax-table emacs-lisp-mode-syntax-table
144 0 : (let ((pt (point)))
145 0 : (save-excursion
146 0 : (forward-sexp -1)
147 0 : (read
148 : ;; If first line is commented, ignore all leading comments:
149 0 : (if (save-excursion (beginning-of-line) (looking-at-p "[ \t]*;"))
150 0 : (let ((exp (buffer-substring (point) pt))
151 : (start nil))
152 0 : (while (string-match "\n[ \t]*;+" exp start)
153 0 : (setq start (1+ (match-beginning 0))
154 0 : exp (concat (substring exp 0 start)
155 0 : (substring exp (match-end 0)))))
156 0 : exp)
157 0 : (current-buffer)))))))
158 :
159 : ;;;###autoload
160 : (defun pp-eval-last-sexp (arg)
161 : "Run `pp-eval-expression' on sexp before point.
162 : With argument, pretty-print output into current buffer.
163 : Ignores leading comment characters."
164 : (interactive "P")
165 0 : (if arg
166 0 : (insert (pp-to-string (eval (pp-last-sexp) lexical-binding)))
167 0 : (pp-eval-expression (pp-last-sexp))))
168 :
169 : ;;;###autoload
170 : (defun pp-macroexpand-last-sexp (arg)
171 : "Run `pp-macroexpand-expression' on sexp before point.
172 : With argument, pretty-print output into current buffer.
173 : Ignores leading comment characters."
174 : (interactive "P")
175 0 : (if arg
176 0 : (insert (pp-to-string (macroexpand-1 (pp-last-sexp))))
177 0 : (pp-macroexpand-expression (pp-last-sexp))))
178 :
179 : (provide 'pp) ; so (require 'pp) works
180 :
181 : ;;; pp.el ends here
|