Revert "Backport HTTPS proxy fix"
[emacs.git] / src / casetab.c
blob2461647bb1391694fcfa4653ef586149091698cd
1 /* GNU Emacs routines to deal with case tables.
2 Copyright (C) 1993-1994, 2001-2016 Free Software Foundation, Inc.
4 Author: Howard Gayle
6 This file is part of GNU Emacs.
8 GNU Emacs is free software: you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation, either version 3 of the License, or (at
11 your option) any later version.
13 GNU Emacs is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. */
21 #include <config.h>
23 #include "lisp.h"
24 #include "buffer.h"
26 Lisp_Object Vascii_downcase_table;
27 static Lisp_Object Vascii_upcase_table;
28 Lisp_Object Vascii_canon_table;
29 static Lisp_Object Vascii_eqv_table;
31 static void set_canon (Lisp_Object case_table, Lisp_Object range, Lisp_Object elt);
32 static void set_identity (Lisp_Object table, Lisp_Object c, Lisp_Object elt);
33 static void shuffle (Lisp_Object table, Lisp_Object c, Lisp_Object elt);
35 DEFUN ("case-table-p", Fcase_table_p, Scase_table_p, 1, 1, 0,
36 doc: /* Return t if OBJECT is a case table.
37 See `set-case-table' for more information on these data structures. */)
38 (Lisp_Object object)
40 Lisp_Object up, canon, eqv;
42 if (! CHAR_TABLE_P (object))
43 return Qnil;
44 if (! EQ (XCHAR_TABLE (object)->purpose, Qcase_table))
45 return Qnil;
47 up = XCHAR_TABLE (object)->extras[0];
48 canon = XCHAR_TABLE (object)->extras[1];
49 eqv = XCHAR_TABLE (object)->extras[2];
51 return ((NILP (up) || CHAR_TABLE_P (up))
52 && ((NILP (canon) && NILP (eqv))
53 || (CHAR_TABLE_P (canon)
54 && (NILP (eqv) || CHAR_TABLE_P (eqv))))
55 ? Qt : Qnil);
58 static Lisp_Object
59 check_case_table (Lisp_Object obj)
61 CHECK_TYPE (!NILP (Fcase_table_p (obj)), Qcase_table_p, obj);
62 return (obj);
65 DEFUN ("current-case-table", Fcurrent_case_table, Scurrent_case_table, 0, 0, 0,
66 doc: /* Return the case table of the current buffer. */)
67 (void)
69 return BVAR (current_buffer, downcase_table);
72 DEFUN ("standard-case-table", Fstandard_case_table, Sstandard_case_table, 0, 0, 0,
73 doc: /* Return the standard case table.
74 This is the one used for new buffers. */)
75 (void)
77 return Vascii_downcase_table;
80 static Lisp_Object set_case_table (Lisp_Object, bool);
82 DEFUN ("set-case-table", Fset_case_table, Sset_case_table, 1, 1, 0,
83 doc: /* Select a new case table for the current buffer.
84 A case table is a char-table which maps characters
85 to their lower-case equivalents. It also has three \"extra\" slots
86 which may be additional char-tables or nil.
87 These slots are called UPCASE, CANONICALIZE and EQUIVALENCES.
88 UPCASE maps each non-upper-case character to its upper-case equivalent.
89 (The value in UPCASE for an upper-case character is never used.)
90 If lower and upper case characters are in 1-1 correspondence,
91 you may use nil and the upcase table will be deduced from DOWNCASE.
92 CANONICALIZE maps each character to a canonical equivalent;
93 any two characters that are related by case-conversion have the same
94 canonical equivalent character; it may be nil, in which case it is
95 deduced from DOWNCASE and UPCASE.
96 EQUIVALENCES is a map that cyclically permutes each equivalence class
97 (of characters with the same canonical equivalent); it may be nil,
98 in which case it is deduced from CANONICALIZE. */)
99 (Lisp_Object table)
101 return set_case_table (table, 0);
104 DEFUN ("set-standard-case-table", Fset_standard_case_table,
105 Sset_standard_case_table, 1, 1, 0,
106 doc: /* Select a new standard case table for new buffers.
107 See `set-case-table' for more info on case tables. */)
108 (Lisp_Object table)
110 return set_case_table (table, 1);
113 static Lisp_Object
114 set_case_table (Lisp_Object table, bool standard)
116 Lisp_Object up, canon, eqv;
118 check_case_table (table);
120 up = XCHAR_TABLE (table)->extras[0];
121 canon = XCHAR_TABLE (table)->extras[1];
122 eqv = XCHAR_TABLE (table)->extras[2];
124 if (NILP (up))
126 up = Fmake_char_table (Qcase_table, Qnil);
127 map_char_table (set_identity, Qnil, table, up);
128 map_char_table (shuffle, Qnil, table, up);
129 set_char_table_extras (table, 0, up);
132 if (NILP (canon))
134 canon = Fmake_char_table (Qcase_table, Qnil);
135 set_char_table_extras (table, 1, canon);
136 map_char_table (set_canon, Qnil, table, table);
139 if (NILP (eqv))
141 eqv = Fmake_char_table (Qcase_table, Qnil);
142 map_char_table (set_identity, Qnil, canon, eqv);
143 map_char_table (shuffle, Qnil, canon, eqv);
144 set_char_table_extras (table, 2, eqv);
147 /* This is so set_image_of_range_1 in regex.c can find the EQV table. */
148 set_char_table_extras (canon, 2, eqv);
150 if (standard)
152 Vascii_downcase_table = table;
153 Vascii_upcase_table = up;
154 Vascii_canon_table = canon;
155 Vascii_eqv_table = eqv;
157 else
159 bset_downcase_table (current_buffer, table);
160 bset_upcase_table (current_buffer, up);
161 bset_case_canon_table (current_buffer, canon);
162 bset_case_eqv_table (current_buffer, eqv);
165 return table;
168 /* The following functions are called in map_char_table. */
170 /* Set CANON char-table element for characters in RANGE to a
171 translated ELT by UP and DOWN char-tables. This is done only when
172 ELT is a character. The char-tables CANON, UP, and DOWN are in
173 CASE_TABLE. */
175 static void
176 set_canon (Lisp_Object case_table, Lisp_Object range, Lisp_Object elt)
178 Lisp_Object up = XCHAR_TABLE (case_table)->extras[0];
179 Lisp_Object canon = XCHAR_TABLE (case_table)->extras[1];
181 if (NATNUMP (elt))
182 Fset_char_table_range (canon, range, Faref (case_table, Faref (up, elt)));
185 /* Set elements of char-table TABLE for C to C itself. C may be a
186 cons specifying a character range. In that case, set characters in
187 that range to themselves. This is done only when ELT is a
188 character. This is called in map_char_table. */
190 static void
191 set_identity (Lisp_Object table, Lisp_Object c, Lisp_Object elt)
193 if (NATNUMP (elt))
195 int from, to;
197 if (CONSP (c))
199 from = XINT (XCAR (c));
200 to = XINT (XCDR (c));
202 else
203 from = to = XINT (c);
205 to++;
206 for (; from < to; from++)
207 CHAR_TABLE_SET (table, from, make_number (from));
211 /* Permute the elements of TABLE (which is initially an identity
212 mapping) so that it has one cycle for each equivalence class
213 induced by the translation table on which map_char_table is
214 operated. */
216 static void
217 shuffle (Lisp_Object table, Lisp_Object c, Lisp_Object elt)
219 if (NATNUMP (elt))
221 int from, to;
223 if (CONSP (c))
225 from = XINT (XCAR (c));
226 to = XINT (XCDR (c));
228 else
229 from = to = XINT (c);
231 to++;
232 for (; from < to; from++)
234 Lisp_Object tem = Faref (table, elt);
235 Faset (table, elt, make_number (from));
236 Faset (table, make_number (from), tem);
241 void
242 init_casetab_once (void)
244 register int i;
245 Lisp_Object down, up, eqv;
247 DEFSYM (Qcase_table, "case-table");
248 Fput (Qcase_table, Qchar_table_extra_slots, make_number (3));
250 down = Fmake_char_table (Qcase_table, Qnil);
251 Vascii_downcase_table = down;
252 set_char_table_purpose (down, Qcase_table);
254 for (i = 0; i < 128; i++)
256 int c = (i >= 'A' && i <= 'Z') ? i + ('a' - 'A') : i;
257 CHAR_TABLE_SET (down, i, make_number (c));
260 set_char_table_extras (down, 1, Fcopy_sequence (down));
262 up = Fmake_char_table (Qcase_table, Qnil);
263 set_char_table_extras (down, 0, up);
265 for (i = 0; i < 128; i++)
267 int c = (i >= 'a' && i <= 'z') ? i + ('A' - 'a') : i;
268 CHAR_TABLE_SET (up, i, make_number (c));
271 eqv = Fmake_char_table (Qcase_table, Qnil);
273 for (i = 0; i < 128; i++)
275 int c = ((i >= 'A' && i <= 'Z') ? i + ('a' - 'A')
276 : ((i >= 'a' && i <= 'z') ? i + ('A' - 'a')
277 : i));
278 CHAR_TABLE_SET (eqv, i, make_number (c));
281 set_char_table_extras (down, 2, eqv);
283 /* Fill in what isn't filled in. */
284 set_case_table (down, 1);
287 void
288 syms_of_casetab (void)
290 DEFSYM (Qcase_table_p, "case-table-p");
292 staticpro (&Vascii_canon_table);
293 staticpro (&Vascii_downcase_table);
294 staticpro (&Vascii_eqv_table);
295 staticpro (&Vascii_upcase_table);
297 defsubr (&Scase_table_p);
298 defsubr (&Scurrent_case_table);
299 defsubr (&Sstandard_case_table);
300 defsubr (&Sset_case_table);
301 defsubr (&Sset_standard_case_table);