Commit | Line | Data |
---|---|---|
15689fa7 GM |
1 | ;;; format-spec.el --- functions for formatting arbitrary formatting strings |
2 | ||
73b0cd50 | 3 | ;; Copyright (C) 1999-2011 Free Software Foundation, Inc. |
15689fa7 GM |
4 | |
5 | ;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> | |
6 | ;; Keywords: tools | |
7 | ||
8 | ;; This file is part of GNU Emacs. | |
9 | ||
eb3fa2cf | 10 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
15689fa7 | 11 | ;; it under the terms of the GNU General Public License as published by |
eb3fa2cf GM |
12 | ;; the Free Software Foundation, either version 3 of the License, or |
13 | ;; (at your option) any later version. | |
15689fa7 GM |
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 | |
eb3fa2cf | 21 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
15689fa7 GM |
22 | |
23 | ;;; Commentary: | |
24 | ||
25 | ;;; Code: | |
26 | ||
27 | (eval-when-compile (require 'cl)) | |
28 | ||
29 | (defun format-spec (format specification) | |
30 | "Return a string based on FORMAT and SPECIFICATION. | |
31 | FORMAT is a string containing `format'-like specs like \"bash %u %k\", | |
32 | while SPECIFICATION is an alist mapping from format spec characters | |
33 | to values. Any text properties on a %-spec itself are propagated to | |
34 | the text that it generates." | |
35 | (with-temp-buffer | |
36 | (insert format) | |
37 | (goto-char (point-min)) | |
38 | (while (search-forward "%" nil t) | |
39 | (cond | |
40 | ;; Quoted percent sign. | |
41 | ((eq (char-after) ?%) | |
42 | (delete-char 1)) | |
43 | ;; Valid format spec. | |
44 | ((looking-at "\\([-0-9.]*\\)\\([a-zA-Z]\\)") | |
45 | (let* ((num (match-string 1)) | |
46 | (spec (string-to-char (match-string 2))) | |
47 | (val (cdr (assq spec specification)))) | |
48 | (unless val | |
49 | (error "Invalid format character: `%%%c'" spec)) | |
50 | ;; Pad result to desired length. | |
51 | (let ((text (format (concat "%" num "s") val))) | |
52 | ;; Insert first, to preserve text properties. | |
53 | (insert-and-inherit text) | |
54 | ;; Delete the specifier body. | |
55 | (delete-region (+ (match-beginning 0) (length text)) | |
56 | (+ (match-end 0) (length text))) | |
57 | ;; Delete the percent sign. | |
58 | (delete-region (1- (match-beginning 0)) (match-beginning 0))))) | |
59 | ;; Signal an error on bogus format strings. | |
60 | (t | |
61 | (error "Invalid format string")))) | |
62 | (buffer-string))) | |
63 | ||
64 | (defun format-spec-make (&rest pairs) | |
65 | "Return an alist suitable for use in `format-spec' based on PAIRS. | |
66 | PAIRS is a list where every other element is a character and a value, | |
67 | starting with a character." | |
68 | (let (alist) | |
69 | (while pairs | |
70 | (unless (cdr pairs) | |
71 | (error "Invalid list of pairs")) | |
72 | (push (cons (car pairs) (cadr pairs)) alist) | |
73 | (setq pairs (cddr pairs))) | |
74 | (nreverse alist))) | |
75 | ||
76 | (provide 'format-spec) | |
77 | ||
15689fa7 | 78 | ;;; format-spec.el ends here |