--- /dev/null
+;; pp.el --- pretty printer for Emacs Lisp
+;; Copyright (C) 1989, 1993 Free Software Foundation, Inc.
+
+;; Author: Randal Schwartz <merlyn@ora.com>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING. If not, write to
+;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+
+;;; Code:
+
+(defvar pp-escape-newlines t
+ "*Value of print-escape-newlines used by pp-* functions.")
+
+(defun pp-to-string (object)
+ "Return a string containing the pretty-printed representation of OBJECT,
+any Lisp object. Quoting characters are used when needed to make output
+that `read' can handle, whenever this is possible."
+ (save-excursion
+ (set-buffer (generate-new-buffer " pp-to-string"))
+ (unwind-protect
+ (progn
+ (emacs-lisp-mode)
+ (let ((print-escape-newlines pp-escape-newlines))
+ (prin1 object (current-buffer)))
+ (goto-char (point-min))
+ (while (not (eobp))
+ ;; (message "%06d" (- (point-max) (point)))
+ (cond
+ ((looking-at "\\s\(")
+ (while (looking-at "\\s(")
+ (forward-char 1)))
+ ((and (looking-at "\\(quote[ \t]+\\)\\([^.)]\\)")
+ (> (match-beginning 1) 1)
+ (= ?\( (char-after (1- (match-beginning 1))))
+ ;; Make sure this is a two-element list.
+ (save-excursion
+ (goto-char (match-beginning 2))
+ (forward-sexp)
+ ;; (looking-at "[ \t]*\)")
+ ;; Avoid mucking with match-data; does this test work?
+ (char-equal ?\) (char-after (point)))))
+ ;; -1 gets the paren preceding the quote as well.
+ (delete-region (1- (match-beginning 1)) (match-end 1))
+ (insert "'")
+ (forward-sexp 1)
+ (if (looking-at "[ \t]*\)")
+ (delete-region (match-beginning 0) (match-end 0))
+ (error "Malformed quote"))
+ (backward-sexp 1))
+ ((condition-case err-var
+ (prog1 t (down-list 1))
+ (error nil))
+ (backward-char 1)
+ (skip-chars-backward " \t")
+ (delete-region
+ (point)
+ (progn (skip-chars-forward " \t") (point)))
+ (if (not (char-equal ?' (char-after (1- (point)))))
+ (insert ?\n)))
+ ((condition-case err-var
+ (prog1 t (up-list 1))
+ (error nil))
+ (while (looking-at "\\s)")
+ (forward-char 1))
+ (skip-chars-backward " \t")
+ (delete-region
+ (point)
+ (progn (skip-chars-forward " \t") (point)))
+ (if (not (char-equal ?' (char-after (1- (point)))))
+ (insert ?\n)))
+ (t (goto-char (point-max)))))
+ (goto-char (point-min))
+ (indent-sexp)
+ (buffer-string))
+ (kill-buffer (current-buffer)))))
+
+(defun pp (object &optional stream)
+ "Output the pretty-printed representation of OBJECT, any Lisp object.
+Quoting characters are printed when needed to make output that `read'
+can handle, whenever this is possible.
+Output stream is STREAM, or value of `standard-output' (which see)."
+ (princ (pp-to-string object) (or stream standard-output)))
+
+(defun pp-eval-expression (expression)
+ "Evaluate EXPRESSION and pretty-print value into a new display buffer.
+If the pretty-printed value fits on one line, the message line is used
+instead. Value is also consed on to front of variable values 's
+value."
+ (interactive "xPp-eval: ")
+ (setq values (cons (eval expression) values))
+ (let* ((old-show-hook
+ (or (let ((sym (if (> (string-to-int emacs-version) 18)
+ 'temp-buffer-show-function
+ 'temp-buffer-show-hook)))
+ (and (boundp 'sym) (symbol-value sym)))
+ 'display-buffer))
+ (temp-buffer-show-hook
+ (function
+ (lambda (buf)
+ (save-excursion
+ (set-buffer buf)
+ (goto-char (point-min))
+ (end-of-line 1)
+ (if (or (< (1+ (point)) (point-max))
+ (>= (- (point) (point-min)) (screen-width)))
+ (progn
+ (goto-char (point-min)) ; expected by some hooks ...
+ (funcall old-show-hook buf))
+ (message "%s" (buffer-substring (point-min) (point)))
+ (delete-windows-on buf) ; no need to kill it
+ )))))
+ (temp-buffer-show-function temp-buffer-show-hook)) ; emacs19 name
+ (with-output-to-temp-buffer "*Pp Eval Output*"
+ (pp (car values)))
+ (save-excursion
+ (set-buffer "*Pp Eval Output*")
+ (emacs-lisp-mode))))
+
+(defun pp-eval-last-sexp (arg)
+ "Run `pp-eval-expression' on sexp before point (which see).
+With argument, pretty-print output into current buffer.
+Ignores leading comment characters."
+ (interactive "P")
+ (let ((stab (syntax-table)) (pt (point)) start exp)
+ (set-syntax-table emacs-lisp-mode-syntax-table)
+ (save-excursion
+ (forward-sexp -1)
+ ;; If first line is commented, ignore all leading comments:
+ (if (save-excursion (beginning-of-line) (looking-at "[ \t]*;"))
+ (progn
+ (setq exp (buffer-substring (point) pt))
+ (while (string-match "\n[ \t]*;+" exp start)
+ (setq start (1+ (match-beginning 0))
+ exp (concat (substring exp 0 start)
+ (substring exp (match-end 0)))))
+ (setq exp (read exp)))
+ (setq exp (read (current-buffer)))))
+ (set-syntax-table stab)
+ (if arg
+ (insert (pp-to-string (eval exp)))
+ (pp-eval-expression exp))))
+
+;;; Test cases for quote
+;; (pp-eval-expression ''(quote quote))
+;; (pp-eval-expression ''((quote a) (quote b)))
+;; (pp-eval-expression ''('a 'b)) ; same as above
+;; (pp-eval-expression ''((quote (quote quote)) (quote quote)))
+;; These do not satisfy the quote test.
+;; (pp-eval-expression ''quote)
+;; (pp-eval-expression ''(quote))
+;; (pp-eval-expression ''(quote . quote))
+;; (pp-eval-expression ''(quote a b))
+;; (pp-eval-expression ''(quotefoo))
+;; (pp-eval-expression ''(a b))
+
+(provide 'pp) ; so (require 'pp) works
+
+;;; pp.el ends here.
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