/* Declarations having to do with XEmacs syntax tables. Copyright (C) 1985, 1992, 1993 Free Software Foundation, Inc. Copyright (C) 2002, 2003 Ben Wing. This file is part of XEmacs. XEmacs is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. XEmacs is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with XEmacs. If not, see . */ /* Synched up with: FSF 19.28. */ #ifndef INCLUDED_syntax_h_ #define INCLUDED_syntax_h_ #include "chartab.h" /* A syntax table is a type of char table. The values in a syntax table are either integers or conses of integers and chars. The lowest 7 bits of the integer are the syntax class. If this is Sinherit, then the actual syntax value needs to be retrieved from the standard syntax table. It turns out to be worth optimizing lookups of character syntax in two ways. First, although the logic involved in finding the actual integer isn't complex, the syntax value is accessed in functions such as scan_lists() many times for each character scanned. A "mirror syntax table" that contains the actual integers speeds this up. Second, due to the syntax-table text property, the table for looking up syntax may change from character to character. Since looking up properties is expensive, a "syntax cache" which contains the current syntax table and the region where it is valid can speed up linear scans dramatically. The low 7 bits of the integer is a code, as follows. The 8th bit is used as the prefix bit flag (see below). */ enum syntaxcode { Swhitespace, /* whitespace character */ Spunct, /* random punctuation character */ Sword, /* word constituent */ Ssymbol, /* symbol constituent but not word constituent */ Sopen, /* a beginning delimiter */ Sclose, /* an ending delimiter */ Squote, /* a prefix character like Lisp ' */ Sstring, /* a string-grouping character like Lisp " */ Smath, /* delimiters like $ in TeX. */ Sescape, /* a character that begins a C-style escape */ Scharquote, /* a character that quotes the following character */ Scomment, /* a comment-starting character */ Sendcomment, /* a comment-ending character */ Sinherit, /* use the standard syntax table for this character */ Scomment_fence, /* Starts/ends comment which is delimited on the other side by a char with the same syntaxcode. */ Sstring_fence, /* Starts/ends string which is delimited on the other side by a char with the same syntaxcode. */ Smax /* Upper bound on codes that are meaningful */ }; enum syntaxcode charset_syntax (struct buffer *buf, Lisp_Object charset, int *multi_p_out); void update_syntax_table (Lisp_Object table); DECLARE_INLINE_HEADER ( void update_mirror_syntax_if_dirty (Lisp_Object table) ) { if (XCHAR_TABLE (table)->dirty) update_syntax_table (table); } /* Return the syntax code for a particular character and mirror table. */ DECLARE_INLINE_HEADER ( int SYNTAX_CODE (Lisp_Object table, Ichar c) ) { type_checking_assert (XCHAR_TABLE (table)->mirror_table_p); update_mirror_syntax_if_dirty (table); return XFIXNUM (get_char_table_1 (c, table)); } #ifdef NOT_WORTH_THE_EFFORT /* Same but skip the dirty check. */ DECLARE_INLINE_HEADER ( int SYNTAX_CODE_1 (Lisp_Object table, Ichar c) ) { type_checking_assert (XCHAR_TABLE (table)->mirror_table_p); return (enum syntaxcode) XFIXNUM (get_char_table_1 (c, table)); } #endif /* NOT_WORTH_THE_EFFORT */ #define SYNTAX_FROM_CODE(code) ((enum syntaxcode) ((code) & 0177)) #define SYNTAX(table, c) SYNTAX_FROM_CODE (SYNTAX_CODE (table, c)) DECLARE_INLINE_HEADER ( int WORD_SYNTAX_P (Lisp_Object table, Ichar c) ) { return SYNTAX (table, c) == Sword; } /* OK, here's a graphic diagram of the format of the syntax values. Here, the value has already been extracted from the Lisp integer, so there are no tag bits to worry about. Bit number: [ 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 ] [ 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 ] | <-----------> <-------------> <-------------> ^ <-----------> | unused |comment bits | unused | syntax code v | | | | | | | | | unusable | | | | | | | | | due to | | | | | | | | | type tag | | | | | | | | `--> prefix flag in Lisp | | | | | | | | integer | | | | | | | `--> comment end style B, second char | | | | | | `----> comment end style A, second char | | | | | `------> comment end style B, first char | | | | `--------> comment end style A, first char | | | `----------> comment start style B, second char | | `------------> comment start style A, second char | `--------------> comment start style B, first char `----------------> comment start style A, first char In a 64-bit integer, there would be 32 more unused bits between the unusable bit and the comment bits. In older versions of XEmacs, bits 8-14 contained the matching character for parentheses. Such a scheme will not work for Mule, because the matching parenthesis could be any character and requires 21 bits, which we don't have on a 32-bit platform. What we do is use another char table for the matching parenthesis and store a pointer to it in the first char table. (This frees code from having to worry about passing two tables around.) */ /* The prefix flag bit for backward-prefix-chars is in bit 7. */ #define SYNTAX_PREFIX(table, c) \ ((SYNTAX_CODE (table, c) >> 7) & 1) /* Bits 23-16 are used to implement up to two comment styles in a single buffer. They have the following meanings: bit 23 first of a one or two character comment-start sequence of style a. 22 first of a one or two character comment-start sequence of style b. 21 second of a two-character comment-start sequence of style a. 20 second of a two-character comment-start sequence of style b. 19 first of a one or two character comment-end sequence of style a. 18 first of a one or two character comment-end sequence of style b. 17 second of a two-character comment-end sequence of style a. 16 second of a two-character comment-end sequence of style b. */ #define SYNTAX_COMMENT_BITS(table, c) \ ((SYNTAX_CODE (table, c) >> 16) &0xff) #define SYNTAX_FIRST_OF_START_A 0x80 #define SYNTAX_FIRST_OF_START_B 0x40 #define SYNTAX_SECOND_OF_START_A 0x20 #define SYNTAX_SECOND_OF_START_B 0x10 #define SYNTAX_FIRST_OF_END_A 0x08 #define SYNTAX_FIRST_OF_END_B 0x04 #define SYNTAX_SECOND_OF_END_A 0x02 #define SYNTAX_SECOND_OF_END_B 0x01 #define SYNTAX_COMMENT_STYLE_A 0xaa #define SYNTAX_COMMENT_STYLE_B 0x55 #define SYNTAX_FIRST_CHAR_START 0xc0 #define SYNTAX_FIRST_CHAR_END 0x0c #define SYNTAX_FIRST_CHAR 0xcc #define SYNTAX_SECOND_CHAR_START 0x30 #define SYNTAX_SECOND_CHAR_END 0x03 #define SYNTAX_SECOND_CHAR 0x33 /* Array of syntax codes, indexed by characters which designate them. Designators must be ASCII characters (ie, in the range 0x00-0x7F). Bounds checking is the responsibility of calling code. */ extern const unsigned char syntax_spec_code[0200]; /* Array of designators indexed by syntax code. Indicies should be of type enum syntaxcode. */ extern const unsigned char syntax_code_spec[]; Lisp_Object scan_lists (struct buffer *buf, Charbpos from, int count, int depth, int sexpflag, int no_error); int char_quoted (struct buffer *buf, Charbpos pos); /* TABLE is a syntax table, not the mirror table. */ Lisp_Object syntax_match (Lisp_Object table, Ichar ch); extern int no_quit_in_re_search; /****************************** syntax caches ********************************/ extern int lookup_syntax_properties; /* The `syntax-table' property overrides the syntax table or directly specifies the syntax. Since looking up properties is expensive, we cache the information about the syntax-table property. When moving linearly through text (e.g. in the regex routines or the scanning routines in syntax.c), recalculation is needed only when the syntax-table property changes (i.e. not every position). When we do need to recalculate, we can update the info from the previous info faster than if we did the whole calculation from scratch. #### sjt sez: I'm not sure I believe that last claim. That seems to require that we use directional information, etc, but that is ignored in the current implementation. */ enum syntax_source { syntax_source_property_code = 0, syntax_source_property_table = 1, syntax_source_buffer_table = 2 }; #define SOURCE_IS_TABLE(source) (source) struct syntax_cache { #ifdef NEW_GC NORMAL_LISP_OBJECT_HEADER header; #endif /* NEW_GC */ enum syntax_source source; /* Source of syntax information: the buffer's syntax table, a syntax table specified by a syntax-table property, or a syntax code specified by a syntax-table property. */ Lisp_Object object; /* The buffer or string the current syntax cache applies to, or Qnil for a string of text not coming from a buffer or string. */ struct buffer *buffer; /* The buffer that supplies the syntax tables, or NULL for the standard syntax table. If OBJECT is a buffer, this will always be the same buffer. */ int syntax_code; /* Syntax code of current char. */ Lisp_Object syntax_table; /* Syntax table for current pos. */ Lisp_Object mirror_table; /* Mirror table for this table. */ Lisp_Object start, end; /* Markers to keep track of the known region in a buffer. Both are Qnil if object is a string. Normally these correspond to prev_change and next_change, respectively, except when insertions and deletions occur. Then prev_change and next change will be refreshed from these markers. See signal_syntax_cache_extent_adjust(). We'd like to use an extent, but it seems that having an extent over the entire buffer causes serious slowdowns in extent operations! Yuck! #### May not be true any more. */ Charxpos next_change; /* Position of the next extent change. */ Charxpos prev_change; /* Position of the previous extent change. */ }; #ifdef NEW_GC typedef struct syntax_cache Lisp_Syntax_Cache; DECLARE_LISP_OBJECT (syntax_cache, Lisp_Syntax_Cache); #define XSYNTAX_CACHE(x) \ XRECORD (x, syntax_cache, Lisp_Syntax_Cache) #define wrap_syntax_cache(p) wrap_record (p, syntax_cache) #define SYNTAX_CACHE_P(x) RECORDP (x, syntax_cache) #define CHECK_SYNTAX_CACHE(x) CHECK_RECORD (x, syntax_cache) #define CONCHECK_SYNTAX_CACHE(x) CONCHECK_RECORD (x, syntax_cache) #endif /* NEW_GC */ extern const struct sized_memory_description syntax_cache_description; /* Note that the external interface to the syntax cache uses charpos's, but internally we use bytepos's, for speed. */ void update_syntax_cache (struct syntax_cache *cache, Charxpos pos, int count); struct syntax_cache *setup_syntax_cache (struct syntax_cache *cache, Lisp_Object object, struct buffer *buffer, Charxpos from, int count); struct syntax_cache *setup_buffer_syntax_cache (struct buffer *buffer, Charxpos from, int count); /* Make syntax cache state good for CHARPOS, assuming it is currently good for a position before CHARPOS. */ DECLARE_INLINE_HEADER ( void UPDATE_SYNTAX_CACHE_FORWARD (struct syntax_cache *cache, Charxpos pos) ) { /* #### Formerly this function, and the next one, had if (pos < cache->prev_change || pos >= cache->next_change) just like for plain UPDATE_SYNTAX_CACHE. However, sometimes the value of POS may be invalid (particularly, it may be 0 for a buffer). FSF has the check at only one end, so let's try the same. */ if (pos >= cache->next_change) update_syntax_cache (cache, pos, 1); } /* Make syntax cache state good for CHARPOS, assuming it is currently good for a position after CHARPOS. */ DECLARE_INLINE_HEADER ( void UPDATE_SYNTAX_CACHE_BACKWARD (struct syntax_cache *cache, Charxpos pos) ) { if (pos < cache->prev_change) update_syntax_cache (cache, pos, -1); } /* Make syntax cache state good for CHARPOS */ DECLARE_INLINE_HEADER ( void UPDATE_SYNTAX_CACHE (struct syntax_cache *cache, Charxpos pos) ) { if (pos < cache->prev_change || pos >= cache->next_change) update_syntax_cache (cache, pos, 0); } #define SYNTAX_FROM_CACHE(cache, c) \ SYNTAX_FROM_CODE (SYNTAX_CODE_FROM_CACHE (cache, c)) #define SYNTAX_CODE_FROM_CACHE(cache, c) \ (SOURCE_IS_TABLE ((cache)->source) \ ? SYNTAX_CODE ((cache)->mirror_table, c) \ : (cache)->syntax_code) #ifdef NOT_WORTH_THE_EFFORT /* If we really cared about the theoretical performance hit of the dirty check in SYNTAX_CODE, we could use SYNTAX_CODE_1 and endeavor to always keep the mirror table clean, e.g. by checking for dirtiness at the time we set up the syntax cache. There are lots of potential problems, of course -- incomplete understanding of the possible pathways into the code, with some that are bypassing the setups, Lisp code being executed in the meantime that could change things (e.g. QUIT is called in many functions and could execute arbitrary Lisp very easily), etc. The QUIT problem is the biggest one, probably, and one of the main reasons it's probably just not worth it. */ #define SYNTAX_CODE_FROM_CACHE(cache, c) \ (SOURCE_IS_TABLE ((cache)->source) \ ? SYNTAX_CODE_1 ((cache)->mirror_table, c) \ : (cache)->syntax_code) #endif /***************************** syntax code macros ****************************/ #define SYNTAX_CODE_PREFIX(c) \ ((c >> 7) & 1) #define SYNTAX_CODE_COMMENT_BITS(c) \ ((c >> 16) &0xff) #define SYNTAX_CODES_START_P(a, b) \ (((SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_FIRST_CHAR_START) >> 2) \ & (SYNTAX_CODE_COMMENT_BITS (b) & SYNTAX_SECOND_CHAR_START)) #define SYNTAX_CODES_END_P(a, b) \ (((SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_FIRST_CHAR_END) >> 2) \ & (SYNTAX_CODE_COMMENT_BITS (b) & SYNTAX_SECOND_CHAR_END)) #define SYNTAX_CODES_COMMENT_MASK_START(a, b) \ (SYNTAX_CODES_MATCH_START_P (a, b, SYNTAX_COMMENT_STYLE_A) \ ? SYNTAX_COMMENT_STYLE_A \ : (SYNTAX_CODES_MATCH_START_P (a, b, SYNTAX_COMMENT_STYLE_B) \ ? SYNTAX_COMMENT_STYLE_B \ : 0)) #define SYNTAX_CODES_COMMENT_MASK_END(a, b) \ (SYNTAX_CODES_MATCH_END_P (a, b, SYNTAX_COMMENT_STYLE_A) \ ? SYNTAX_COMMENT_STYLE_A \ : (SYNTAX_CODES_MATCH_END_P (a, b, SYNTAX_COMMENT_STYLE_B) \ ? SYNTAX_COMMENT_STYLE_B \ : 0)) #define SYNTAX_CODE_START_FIRST_P(a) \ (SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_FIRST_CHAR_START) #define SYNTAX_CODE_START_SECOND_P(a) \ (SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_SECOND_CHAR_START) #define SYNTAX_CODE_END_FIRST_P(a) \ (SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_FIRST_CHAR_END) #define SYNTAX_CODE_END_SECOND_P(a) \ (SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_SECOND_CHAR_END) #define SYNTAX_CODES_MATCH_START_P(a, b, mask) \ ((SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_FIRST_CHAR_START & (mask)) \ && (SYNTAX_CODE_COMMENT_BITS (b) \ & SYNTAX_SECOND_CHAR_START & (mask))) #define SYNTAX_CODES_MATCH_END_P(a, b, mask) \ ((SYNTAX_CODE_COMMENT_BITS (a) & SYNTAX_FIRST_CHAR_END & (mask)) \ && (SYNTAX_CODE_COMMENT_BITS (b) & SYNTAX_SECOND_CHAR_END & (mask))) #define SYNTAX_CODE_MATCHES_1CHAR_P(a, mask) \ ((SYNTAX_CODE_COMMENT_BITS (a) & (mask))) #define SYNTAX_CODE_COMMENT_1CHAR_MASK(a) \ ((SYNTAX_CODE_MATCHES_1CHAR_P (a, SYNTAX_COMMENT_STYLE_A) \ ? SYNTAX_COMMENT_STYLE_A \ : (SYNTAX_CODE_MATCHES_1CHAR_P (a, SYNTAX_COMMENT_STYLE_B) \ ? SYNTAX_COMMENT_STYLE_B \ : 0))) #endif /* INCLUDED_syntax_h_ */