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#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
#include <string.h>
struct token {
enum symbol {
LPAREN, RPAREN, STRING, IDEN, NUM
} sym;
union {
char *iden;
int i;
char *str;
};
};
static struct token tok;
static inline int issep(char c)
{
return isspace(c) || c == '\0' || c == '}' || c == '{' || c == '"';
}
static inline int tillsep(char *str)
{
size_t i = 0;
while(!issep(str[i++]));
return i-1;
}
static inline char *substring(char *str, size_t sub_end)
{
static char sub[128];
if(sub_end+1 > sizeof(sub)) return NULL;
sub[sub_end+1] = '\0';
return memcpy(sub, str, sub_end);
}
static char *next_token(char *str)
{
size_t off = 0;
char c0 = str[0];
if(c0 == '\0') return NULL;
if(isspace(c0)) return next_token(str+1);
else {
off = tillsep(str);
if(off == 0) { // sep
switch(str[off++]) {
case '{': tok.sym = LPAREN; break;
case '}': tok.sym = RPAREN; break;
case '"':
while(str[off] != '"') if(str[off++] == '\0') return NULL;
tok.sym = STRING;
tok.str = strdup(substring(str, off));
}
} else if(isalpha(c0)) { // iden
tok.sym = IDEN;
tok.iden = strdup(substring(str, off));
} else if(c0 >= '0' && c0 <= '9') { // num
tok.sym = NUM;
tok.i = atoi(substring(str, off));
}
}
return str+off;
}
int main(void)
{
char *str = "blah 0 1 443 test{here}13}{1\"fdlkfjakl{fher} fdsfj\" here { {tok {";
while((str = next_token(str)))
switch(tok.sym) {
case LPAREN: printf("{ "); break;
case RPAREN: printf("} "); break;
case STRING: printf("\"%s\" ", tok.str); free(tok.str); break;
case IDEN: printf("'%s' ", tok.iden); free(tok.iden); break;
case NUM: printf("%d ", tok.i); break;
}
printf("\n");
return 0;
}
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