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/* Generated by re2c */
#line 1 "calc_006.re"
// re2c $INPUT -o $OUTPUT -s
/* re2c lesson 001_upn_calculator, calc_006, (c) M. Boerger 2006 - 2007 */
#line 36 "calc_006.re"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define DEBUG(stmt) stmt
int stack[4];
int depth = 0;
int push_num(const unsigned char *t, const unsigned char *l, int radix)
{
int num = 0;
if (depth >= sizeof(stack))
{
return 3;
}
--t;
while(++t < l)
{
num = num * radix + (*t - (unsigned char)'0');
}
DEBUG(printf("Num: %d\n", num));
stack[depth++] = num;
return 0;
}
int stack_add()
{
if (depth < 2) return 4;
--depth;
stack[depth-1] = stack[depth-1] + stack[depth];
DEBUG(printf("+\n"));
return 0;
}
int stack_sub()
{
if (depth < 2) return 4;
--depth;
stack[depth-1] = stack[depth-1] - stack[depth];
DEBUG(printf("-\n"));
return 0;
}
int scan(char *s)
{
unsigned char *p = (unsigned char*)s;
unsigned char *t;
int res = 0;
#define YYCTYPE unsigned char
#define YYCURSOR p
while(!res)
{
t = p;
#line 71 "calc_006.c"
{
YYCTYPE yych;
yych = *YYCURSOR;
if (yych <= '*') {
if (yych <= '\t') {
if (yych <= 0x00) goto yy1;
if (yych <= 0x08) goto yy2;
goto yy3;
} else {
if (yych == ' ') goto yy3;
goto yy2;
}
} else {
if (yych <= '-') {
if (yych <= '+') goto yy4;
if (yych <= ',') goto yy2;
goto yy5;
} else {
if (yych <= '/') goto yy2;
if (yych <= '0') goto yy6;
if (yych <= '9') goto yy8;
goto yy2;
}
}
yy1:
++YYCURSOR;
#line 113 "calc_006.re"
{ res = depth == 1 ? 0 : 2; break; }
#line 100 "calc_006.c"
yy2:
++YYCURSOR;
#line 114 "calc_006.re"
{ res = 1; continue; }
#line 105 "calc_006.c"
yy3:
yych = *++YYCURSOR;
if (yych == '\t') goto yy3;
if (yych == ' ') goto yy3;
#line 108 "calc_006.re"
{ continue; }
#line 112 "calc_006.c"
yy4:
++YYCURSOR;
#line 111 "calc_006.re"
{ res = stack_add(); continue; }
#line 117 "calc_006.c"
yy5:
++YYCURSOR;
#line 112 "calc_006.re"
{ res = stack_sub(); continue; }
#line 122 "calc_006.c"
yy6:
yych = *++YYCURSOR;
if (yych <= '/') goto yy7;
if (yych <= '9') goto yy9;
yy7:
#line 110 "calc_006.re"
{ res = push_num(t, p, 10); continue; }
#line 130 "calc_006.c"
yy8:
yych = *++YYCURSOR;
if (yych <= '/') goto yy7;
if (yych <= '9') goto yy8;
goto yy7;
yy9:
yych = *++YYCURSOR;
if (yych <= '/') goto yy10;
if (yych <= '9') goto yy9;
yy10:
#line 109 "calc_006.re"
{ res = push_num(t, p, 8); continue; }
#line 143 "calc_006.c"
}
#line 115 "calc_006.re"
}
return res;
}
int main(int argc, char **argv)
{
if (argc > 1)
{
char *inp;
int res = 0, argp = 0, len;
while(!res && ++argp < argc)
{
inp = strdup(argv[argp]);
len = strlen(inp);
if (inp[0] == '\"' && inp[len-1] == '\"')
{
inp[len - 1] = '\0';
++inp;
}
res = scan(inp);
free(inp);
}
switch(res)
{
case 0:
printf("Result: %d\n", stack[0]);
return 0;
case 1:
fprintf(stderr, "Illegal character in input.\n");
return 1;
case 2:
fprintf(stderr, "Premature end of input.\n");
return 2;
case 3:
fprintf(stderr, "Stack overflow.\n");
return 3;
case 4:
fprintf(stderr, "Stack underflow.\n");
return 4;
}
}
else
{
fprintf(stderr, "%s <expr>\n", argv[0]);
return 0;
}
}
|
