mirror of https://github.com/ZDoom/gzdoom-gles.git
62 lines
1.6 KiB
C++
62 lines
1.6 KiB
C++
/* re2c lesson 001_upn_calculator, calc_003, (c) M. Boerger 2006 - 2007 */
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/*!ignore:re2c
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- making use of YYFILL
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. Again provide the length of the input to generate the limit only once. Now
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we can use YYFILL() to detect the end and simply return since YYFILL() is
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only being used if the next scanner run might use more chars then YYLIMIT
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allows.
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. Note that we now use (s+l+2) instead of (s+l) as we did in lesson_001. In
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the first lesson we did not quit from YYFILL() and used a special rule to
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detect the end of input. Here we use the fact that we know the exact end
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of input and that this length does not include the terminating zero. Since
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YYLIMIT points to the first character behind the used buffer we use "+ 2".
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If we would use "+1" we could drop the "\000" rule but could no longer
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distinguish between end of input and out of data.
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*/
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#include <stdlib.h>
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#include <stdio.h>
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#include <string.h>
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int scan(char *s, int l)
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{
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char *p = s;
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char *q = 0;
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#define YYCTYPE char
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#define YYCURSOR p
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#define YYLIMIT (s+l+2)
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#define YYMARKER q
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#define YYFILL(n) { printf("OOD\n"); return 2; }
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for(;;)
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{
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/*!re2c
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re2c:indent:top = 2;
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"0"[0-9]+ { printf("Oct\n"); continue; }
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[1-9][0-9]* { printf("Num\n"); continue; }
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"0" { printf("Num\n"); continue; }
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"+" { printf("+\n"); continue; }
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"-" { printf("+\n"); continue; }
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"\000" { printf("EOF\n"); return 0; }
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[^] { printf("ERR\n"); return 1; }
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*/
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}
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return 0;
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}
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int main(int argc, char **argv)
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{
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if (argc > 1)
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{
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return scan(argv[1], strlen(argv[1]));
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}
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else
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{
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fprintf(stderr, "%s <expr>\n", argv[0]);
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return 0;
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}
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}
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