Avoid segfaults when some display vector is an empty string
[emacs.git] / lisp / nxml / rng-util.el
bloba804771e33a3502d27ff72146e7b6e55d226e303
1 ;;; rng-util.el --- utility functions for RELAX NG library
3 ;; Copyright (C) 2003, 2007-2017 Free Software Foundation, Inc.
5 ;; Author: James Clark
6 ;; Keywords: wp, hypermedia, languages, XML, RelaxNG
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 (defun rng-make-datatypes-uri (uri)
28 (if (string-equal uri "")
29 ;; The spec doesn't say to do this, but it's perfectly conformant
30 ;; and better than using nil, I think.
31 'http://relaxng.org/ns/structure/1.0
32 (intern uri)))
34 (defconst rng-xsd-datatypes-uri
35 (rng-make-datatypes-uri "http://www.w3.org/2001/XMLSchema-datatypes"))
37 (defconst rng-builtin-datatypes-uri (rng-make-datatypes-uri ""))
39 (defun rng-uniquify-eq (list)
40 "Destructively remove `eq' duplicates from LIST."
41 (and list
42 (let ((head list))
43 (while (cdr head)
44 (if (eq (car head) (cadr head))
45 (setcdr head (cddr head)))
46 (setq head (cdr head)))
47 list)))
49 (defun rng-uniquify-equal (list)
50 "Destructively remove `equal' duplicates from LIST."
51 (and list
52 (let ((head list))
53 (while (cdr head)
54 (if (equal (car head) (cadr head))
55 (setcdr head (cddr head)))
56 (setq head (cdr head)))
57 list)))
59 (defun rng-blank-p (str) (string-match "\\`[ \t\n\r]*\\'" str))
61 (defun rng-substq (new old list)
62 "Replace first member of LIST (if any) that is `eq' to OLD by NEW.
63 LIST is not modified."
64 (cond ((null list) nil)
65 ((eq (car list) old)
66 (cons new (cdr list)))
68 (let ((tail (cons (car list)
69 nil))
70 (rest (cdr list)))
71 (setq list tail)
72 (while rest
73 (let ((item (car rest)))
74 (setq rest (cdr rest))
75 (cond ((eq item old)
76 (setcdr tail
77 (cons new rest))
78 (setq rest nil))
80 (setq tail
81 (setcdr tail
82 (cons item nil))))))))
83 list)))
85 (defun rng-escape-string (s)
86 (replace-regexp-in-string "[&\"<>]"
87 (lambda (match)
88 (cdr (assoc match
89 '(("&" . "&amp;")
90 ("\"" . "&quot;")
91 (">" . "&gt;")
92 ("<" . "&lt;")))))
94 t))
96 (defun rng-collapse-space (string)
97 (setq string
98 (replace-regexp-in-string "[ \t\r\n]+" " " string t t))
99 (when (string-match "\\` " string)
100 (setq string (substring string 1)))
101 (when (string-match " \\'" string)
102 (setq string (substring string 0 -1)))
103 string)
105 (define-error 'rng-error nil)
107 (provide 'rng-util)
109 ;;; rng-util.el ends here