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/* Generated by re2c */
#line 1 "calc_005.re"
// re2c $INPUT -o $OUTPUT
/* re2c lesson 001_upn_calculator, calc_005, (c) M. Boerger 2006 - 2007 */
#line 19 "calc_005.re"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define DEBUG(stmt) stmt
int stack[4];
int depth = 0;
int push_num(const char *t, const char *l, int radix)
{
int num = 0;
if (depth >= sizeof(stack))
{
return 3;
}
--t;
while(++t < l)
{
num = num * radix + (*t - '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];
return 0;
}
int stack_sub()
{
if (depth < 2) return 4;
--depth;
stack[depth-1] = stack[depth-1] - stack[depth];
return 0;
}
int scan(char *s, int l)
{
char *p = s;
char *q = 0;
char *t;
int res = 0;
#define YYCTYPE char
#define YYCURSOR p
#define YYLIMIT (s+l+1)
#define YYMARKER q
#define YYFILL(n) { return depth == 1 ? 0 : 2; }
while(!res)
{
t = p;
#line 73 "calc_005.c"
{
YYCTYPE yych;
if ((YYLIMIT - YYCURSOR) < 2) YYFILL(2);
yych = *YYCURSOR;
switch (yych) {
case '\t':
case ' ': goto yy2;
case '+': goto yy4;
case '-': goto yy5;
case '0': goto yy6;
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': goto yy8;
default: goto yy1;
}
yy1:
++YYCURSOR;
#line 97 "calc_005.re"
{ res = 1; continue; }
#line 99 "calc_005.c"
yy2:
++YYCURSOR;
if (YYLIMIT <= YYCURSOR) YYFILL(1);
yych = *YYCURSOR;
switch (yych) {
case '\t':
case ' ': goto yy2;
default: goto yy3;
}
yy3:
#line 92 "calc_005.re"
{ continue; }
#line 112 "calc_005.c"
yy4:
++YYCURSOR;
#line 95 "calc_005.re"
{ res = stack_add(); continue; }
#line 117 "calc_005.c"
yy5:
++YYCURSOR;
#line 96 "calc_005.re"
{ res = stack_sub(); continue; }
#line 122 "calc_005.c"
yy6:
yych = *++YYCURSOR;
switch (yych) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': goto yy9;
default: goto yy7;
}
yy7:
#line 94 "calc_005.re"
{ res = push_num(t, p, 10); continue; }
#line 141 "calc_005.c"
yy8:
++YYCURSOR;
if (YYLIMIT <= YYCURSOR) YYFILL(1);
yych = *YYCURSOR;
switch (yych) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': goto yy8;
default: goto yy7;
}
yy9:
++YYCURSOR;
if (YYLIMIT <= YYCURSOR) YYFILL(1);
yych = *YYCURSOR;
switch (yych) {
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9': goto yy9;
default: goto yy10;
}
yy10:
#line 93 "calc_005.re"
{ res = push_num(t, p, 8); continue; }
#line 179 "calc_005.c"
}
#line 98 "calc_005.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 = argv[argp];
len = strlen(inp);
if (inp[0] == '\"' && inp[len-1] == '\"')
{
++inp;
len -=2;
}
res = scan(inp, len);
}
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;
}
}
|
