1;;; format-spec.el --- functions for formatting arbitrary formatting strings 2 3;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004, 4;; 2005, 2006, 2007 Free Software Foundation, Inc. 5 6;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org> 7;; Keywords: tools 8 9;; This file is part of GNU Emacs. 10 11;; GNU Emacs is free software; you can redistribute it and/or modify 12;; it under the terms of the GNU General Public License as published by 13;; the Free Software Foundation; either version 2, or (at your option) 14;; any later version. 15 16;; GNU Emacs is distributed in the hope that it will be useful, 17;; but WITHOUT ANY WARRANTY; without even the implied warranty of 18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 19;; GNU General Public License for more details. 20 21;; You should have received a copy of the GNU General Public License 22;; along with GNU Emacs; see the file COPYING. If not, write to the 23;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 24;; Boston, MA 02110-1301, USA. 25 26;;; Commentary: 27 28;;; Code: 29 30(eval-when-compile (require 'cl)) 31 32(defun format-spec (format specification) 33 "Return a string based on FORMAT and SPECIFICATION. 34FORMAT is a string containing `format'-like specs like \"bash %u %k\", 35while SPECIFICATION is an alist mapping from format spec characters 36to values. Any text properties on a %-spec itself are propagated to 37the text that it generates." 38 (with-temp-buffer 39 (insert format) 40 (goto-char (point-min)) 41 (while (search-forward "%" nil t) 42 (cond 43 ;; Quoted percent sign. 44 ((eq (char-after) ?%) 45 (delete-char 1)) 46 ;; Valid format spec. 47 ((looking-at "\\([-0-9.]*\\)\\([a-zA-Z]\\)") 48 (let* ((num (match-string 1)) 49 (spec (string-to-char (match-string 2))) 50 (val (cdr (assq spec specification)))) 51 (unless val 52 (error "Invalid format character: %s" spec)) 53 ;; Pad result to desired length. 54 (let ((text (format (concat "%" num "s") val))) 55 ;; Insert first, to preserve text properties. 56 (insert-and-inherit text) 57 ;; Delete the specifier body. 58 (delete-region (+ (match-beginning 0) (length text)) 59 (+ (match-end 0) (length text))) 60 ;; Delete the percent sign. 61 (delete-region (1- (match-beginning 0)) (match-beginning 0))))) 62 ;; Signal an error on bogus format strings. 63 (t 64 (error "Invalid format string")))) 65 (buffer-string))) 66 67(defun format-spec-make (&rest pairs) 68 "Return an alist suitable for use in `format-spec' based on PAIRS. 69PAIRS is a list where every other element is a character and a value, 70starting with a character." 71 (let (alist) 72 (while pairs 73 (unless (cdr pairs) 74 (error "Invalid list of pairs")) 75 (push (cons (car pairs) (cadr pairs)) alist) 76 (setq pairs (cddr pairs))) 77 (nreverse alist))) 78 79(provide 'format-spec) 80 81;;; arch-tag: c22d49cf-d167-445d-b7f1-2504d4173f53 82;;; format-spec.el ends here 83