lisp/nxml/rng-util.el

   1 ;;; rng-util.el --- utility functions for RELAX NG library
   2
   3 ;; Copyright (C) 2003, 2007-2016 Free Software Foundation, Inc.
   4
   5 ;; Author: James Clark
   6 ;; Keywords: wp, hypermedia, languages, XML, RelaxNG
   7
   8 ;; This file is part of GNU Emacs.
   9
  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.
  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
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  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)))
  33
  34 (defconst rng-xsd-datatypes-uri
  35   (rng-make-datatypes-uri "http://www.w3.org/2001/XMLSchema-datatypes"))
  36
  37 (defconst rng-builtin-datatypes-uri (rng-make-datatypes-uri ""))
  38
  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)))
  48
  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)))
  58
  59 (defun rng-blank-p (str) (string-match "\\`[ \t\n\r]*\\'" str))
  60
  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)))
  67         (t
  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))
  79                      (t
  80                       (setq tail
  81                             (setcdr tail
  82                                     (cons item nil))))))))
  83          list)))
  84
  85 (defun rng-complete-before-point (start table prompt &optional predicate hist)
  86   "Complete text between START and point.
  87 Replaces the text between START and point with a string chosen using a
  88 completion table and, when needed, input read from the user with the
  89 minibuffer.
  90 Returns the new string if either a complete and unique completion was
  91 determined automatically or input was read from the user.  Otherwise,
  92 returns nil.
  93 TABLE is an alist, a symbol bound to a function or an obarray as with
  94 the function `completing-read'.
  95 PROMPT is the string to prompt with if user input is needed.
  96 PREDICATE is nil or a function as with `completing-read'.
  97 HIST, if non-nil, specifies a history list as with `completing-read'."
  98   (let* ((orig (buffer-substring-no-properties start (point)))
  99          (completion (try-completion orig table predicate)))
 100     (cond ((not completion)
 101            (if (string= orig "")
 102                (message "No completions available")
 103              (message "No completion for %s" (rng-quote-string orig)))
 104            (ding)
 105            nil)
 106           ((eq completion t) orig)
 107           ((not (string= completion orig))
 108            (delete-region start (point))
 109            (insert completion)
 110            (cond ((not (rng-completion-exact-p completion table predicate))
 111                   (message "Incomplete")
 112                   nil)
 113                  ((eq (try-completion completion table predicate) t)
 114                   completion)
 115                  (t
 116                   (message "Complete but not unique")
 117                   nil)))
 118           (t
 119            (setq completion
 120                  (let ((saved-minibuffer-setup-hook
 121                         (default-value 'minibuffer-setup-hook)))
 122                    (add-hook 'minibuffer-setup-hook
 123                              'minibuffer-completion-help
 124                              t)
 125                    (unwind-protect
 126                        (completing-read prompt
 127                                         table
 128                                         predicate
 129                                         nil
 130                                         orig
 131                                         hist)
 132                      (setq-default minibuffer-setup-hook
 133                                    saved-minibuffer-setup-hook))))
 134            (delete-region start (point))
 135            (insert completion)
 136            completion))))
 137
 138 (defun rng-completion-exact-p (string table predicate)
 139   (cond ((symbolp table)
 140          (funcall table string predicate 'lambda))
 141         ((vectorp table)
 142          (intern-soft string table))
 143         (t (assoc string table))))
 144
 145 (defun rng-quote-string (s)
 146   (concat "\"" s "\""))
 147
 148 (defun rng-escape-string (s)
 149   (replace-regexp-in-string "[&\"<>]"
 150                             (lambda (match)
 151                               (cdr (assoc match
 152                                           '(("&" . "&amp;")
 153                                             ("\"" . "&quot;")
 154                                             (">" . "&gt;")
 155                                             ("<" . "&lt;")))))
 156                             s
 157                             t))
 158
 159 (defun rng-collapse-space (string)
 160   (setq string
 161         (replace-regexp-in-string "[ \t\r\n]+" " " string t t))
 162   (when (string-match "\\` " string)
 163     (setq string (substring string 1)))
 164   (when (string-match " \\'" string)
 165     (setq string (substring string 0 -1)))
 166   string)
 167
 168 (define-error 'rng-error nil)
 169
 170 (provide 'rng-util)
 171
 172 ;;; rng-util.el ends here