Avoid segfaults when some display vector is an empty string
[emacs.git] / lisp / nxml / rng-dt.el
blob6e60609445e317573e1332cc2be7820f34595fd0
1 ;;; rng-dt.el --- datatype library interface for RELAX NG -*- lexical-binding:t -*-
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 (require 'rng-util)
29 (defvar rng-dt-error-reporter nil)
31 (defun rng-dt-error (string &rest objs)
32 (if rng-dt-error-reporter
33 (apply rng-dt-error-reporter (cons string objs))
34 nil))
36 (defvar rng-dt-namespace-context-getter nil
37 "A list used by datatype libraries to expand names.
38 The car of the list is a symbol which is the name of a function.
39 This function is applied to the cdr of the list. The function must
40 return a list whose car is the default namespace and whose cdr is an
41 alist of (PREFIX . NAMESPACE) pairs, where PREFIX is a string and
42 NAMESPACE is a symbol. This must be dynamically bound before calling
43 a datatype library.")
45 (defsubst rng-dt-make-value (dt str)
46 (apply (car dt) (cons str (cdr dt))))
48 (defun rng-dt-builtin-compile (name params)
49 (cond ((eq name 'string)
50 (if (null params)
51 '(t identity)
52 (rng-dt-error "The string datatype does not take any parameters")))
53 ((eq name 'token)
54 (if (null params)
55 '(t rng-collapse-space)
56 (rng-dt-error "The token datatype does not take any parameters")))
58 (rng-dt-error "There is no built-in datatype %s" name))))
60 (put (rng-make-datatypes-uri "") 'rng-dt-compile #'rng-dt-builtin-compile)
62 (provide 'rng-dt)
64 ;;; rng-dt.el ends here