raze/tools/re2c/examples/input_custom/fixed.re
Christoph Oelckers 8c95516224 - added compile tools from GZDoom repo:
- updaterevision for automated revision string generation
- re2c as a prerequisite to use sc_man in the future
- zipdir to automatically generate an engine resource file.
2019-09-22 08:52:30 +02:00

35 lines
1.1 KiB
C++

// Build with "--input custom" re2c switch.
//
// This is an example of handling fixed-length buffer with "--input custom":
// on each YYPEEK we check for the end of input, thus YYFILL generation
// can be safely suppressed.
//
// Note that YYLIMIT points not to terminating NULL, but to the previous
// character: we emulate the case when input has no terminating NULL.
//
// For a real-life example see https://github.com/sopyer/mjson
// or mjson.re from re2c test collection.
bool lex (const char * cursor, const char * const limit)
{
const char * marker;
const char * ctxmarker;
# define YYCTYPE char
# define YYPEEK() (cursor >= limit ? 0 : *cursor)
# define YYSKIP() ++cursor
# define YYBACKUP() marker = cursor
# define YYBACKUPCTX() ctxmarker = cursor
# define YYRESTORE() cursor = marker
# define YYRESTORECTX() cursor = ctxmarker
/*!re2c
re2c:yyfill:enable = 0;
"int buffer " / "[" [0-9]+ "]" { return true; }
* { return false; }
*/
}
int main ()
{
char buffer [] = "int buffer [1024]";
return !lex (buffer, buffer + sizeof (buffer) - 1);
}