calist.el

   1 ;;; calist.el --- Condition functions
   2
   3 ;; Copyright (C) 1998 MORIOKA Tomohiko.
   4
   5 ;; Author: MORIOKA Tomohiko <morioka@jaist.ac.jp>
   6 ;; Keywords: condition, alist, tree
   7
   8 ;; This file is part of APEL (A Portable Emacs Library).
   9
  10 ;; This program is free software; you can redistribute it and/or
  11 ;; modify it under the terms of the GNU General Public License as
  12 ;; published by the Free Software Foundation; either version 2, or (at
  13 ;; your option) any later version.
  14
  15 ;; This program is distributed in the hope that it will be useful, but
  16 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18 ;; 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; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Code:
  26
  27 (eval-when-compile (require 'cl))
  28
  29 (defvar calist-field-match-method-obarray [nil])
  30
  31 (defun define-calist-field-match-method (field-type function)
  32   "Set field-match-method for FIELD-TYPE to FUNCTION."
  33   (fset (intern (symbol-name field-type) calist-field-match-method-obarray)
  34         function))
  35
  36 (defun calist-default-field-match-method (calist field-type field-value)
  37   (let ((s-field (assoc field-type calist)))
  38     (cond ((null s-field)
  39            (cons (cons field-type field-value) calist)
  40            )
  41           ((eq field-value t)
  42            calist)
  43           ((equal (cdr s-field) field-value)
  44            calist))))
  45
  46 (defsubst calist-field-match-method (field-type)
  47   (condition-case nil
  48       (symbol-function
  49        (intern-soft
  50         (symbol-name field-type) calist-field-match-method-obarray))
  51     (error (symbol-function 'calist-default-field-match-method))
  52     ))
  53
  54 (defsubst calist-field-match (calist field-type field-value)
  55   (funcall (calist-field-match-method field-type)
  56            calist field-type field-value))
  57
  58 (defun ctree-match-calist (rule-tree alist)
  59   "Return matched condition-alist if ALIST matches RULE-TREE."
  60   (if (null rule-tree)
  61       alist
  62     (let ((type (car rule-tree))
  63           (choices (cdr rule-tree))
  64           default)
  65       (catch 'tag
  66         (while choices
  67           (let* ((choice (car choices))
  68                  (choice-value (car choice)))
  69             (if (eq choice-value t)
  70                 (setq default choice)
  71               (let ((ret-alist (calist-field-match alist type (car choice))))
  72                 (if ret-alist
  73                     (throw 'tag
  74                            (if (cdr choice)
  75                                (ctree-match-calist (cdr choice) ret-alist)
  76                              ret-alist))
  77                   ))))
  78           (setq choices (cdr choices)))
  79         (if default
  80             (let ((ret-alist (calist-field-match alist type t)))
  81               (if ret-alist
  82                   (if (cdr default)
  83                       (ctree-match-calist (cdr default) ret-alist)
  84                     ret-alist))))
  85         ))))
  86
  87 (defun calist-to-ctree (calist)
  88   "Convert condition-alist CALIST to condition-tree."
  89   (if calist
  90       (let* ((cell (car calist)))
  91         (cons (car cell)
  92               (list (cons (cdr cell)
  93                           (calist-to-ctree (cdr calist))
  94                           ))))))
  95
  96 (defun ctree-add-calist-strictly (ctree calist)
  97   "Add condition CALIST to condition-tree CTREE without default clause."
  98   (cond ((null calist) ctree)
  99         ((null ctree)
 100          (calist-to-ctree calist)
 101          )
 102         (t
 103          (let* ((type (car ctree))
 104                 (values (cdr ctree))
 105                 (ret (assoc type calist)))
 106            (if ret
 107                (catch 'tag
 108                  (while values
 109                    (let ((cell (car values)))
 110                      (if (equal (car cell)(cdr ret))
 111                          (throw 'tag
 112                                 (setcdr cell
 113                                         (ctree-add-calist-strictly
 114                                          (cdr cell)
 115                                          (delete ret (copy-alist calist)))
 116                                         ))))
 117                    (setq values (cdr values)))
 118                  (setcdr ctree (cons (cons (cdr ret)
 119                                            (calist-to-ctree
 120                                             (delete ret (copy-alist calist))))
 121                                      (cdr ctree)))
 122                  )
 123              (catch 'tag
 124                (while values
 125                  (let ((cell (car values)))
 126                    (setcdr cell
 127                            (ctree-add-calist-strictly (cdr cell) calist))
 128                    )
 129                  (setq values (cdr values))))
 130              )
 131            ctree))))
 132
 133 (defun ctree-add-calist-with-default (ctree calist)
 134   "Add condition CALIST to condition-tree CTREE with default clause."
 135   (cond ((null calist) ctree)
 136         ((null ctree)
 137          (let* ((cell (car calist))
 138                 (type (car cell))
 139                 (value (cdr cell)))
 140            (cons type
 141                  (list '(t)
 142                        (cons value (calist-to-ctree (cdr calist)))))
 143            ))
 144         (t
 145          (let* ((type (car ctree))
 146                 (values (cdr ctree))
 147                 (ret (assoc type calist)))
 148            (if ret
 149                (catch 'tag
 150                  (while values
 151                    (let ((cell (car values)))
 152                      (if (equal (car cell)(cdr ret))
 153                          (throw 'tag
 154                                 (setcdr cell
 155                                         (ctree-add-calist-with-default
 156                                          (cdr cell)
 157                                          (delete ret (copy-alist calist)))
 158                                         ))))
 159                    (setq values (cdr values)))
 160                  (setcdr ctree (list* '(t)
 161                                       (cons (cdr ret)
 162                                             (calist-to-ctree
 163                                              (delete ret (copy-alist calist))))
 164                                       (cdr ctree)))
 165                  )
 166              (catch 'tag
 167                (while values
 168                  (let ((cell (car values)))
 169                    (setcdr cell
 170                            (ctree-add-calist-with-default (cdr cell) calist))
 171                    )
 172                  (setq values (cdr values)))
 173                (let ((elt (cons t (calist-to-ctree calist))))
 174                  (or (member elt (cdr ctree))
 175                      (setcdr ctree (cons elt (cdr ctree)))
 176                      )))
 177              )
 178            ctree))))
 179
 180 (defun ctree-set-calist-strictly (ctree-var calist)
 181   "Set condition CALIST in CTREE-VAR without default clause."
 182   (set ctree-var
 183        (ctree-add-calist-strictly (symbol-value ctree-var) calist)))
 184
 185 (defun ctree-set-calist-with-default (ctree-var calist)
 186   "Set condition CALIST to CTREE-VAR with default clause."
 187   (set ctree-var
 188        (ctree-add-calist-with-default (symbol-value ctree-var) calist)))
 189
 190
 191 ;;; @ end
 192 ;;;
 193
 194 (provide 'calist)
 195
 196 ;;; calist.el ends here