Thun/implementations/C/parser.c

59 lines
1.5 KiB
C

#include <stddef.h>
#include <stdio.h>
#include <string.h>
#include <gc.h>
const char *BLANKS = " \t";
const char *TEXT = "hi there fr [[] ie]nd] [] 23 ";
/* 01234567890123456789
^ ^
*/
char *
trim_leading_blanks(char *str)
{
size_t offset = strspn(str, BLANKS);
if (offset == strlen(str)) {
/* All blanks. */
return NULL;
}
return str + offset;
}
int
main(void)
{
char *rest, *text, *snip;
ptrdiff_t diff;
text = trim_leading_blanks((char *)TEXT);
rest = strpbrk(text, " []");
while (NULL != rest) {
/* How many chars have we got? */
diff = rest - text;
if (diff) {
/* Allocate space and copy out the substring. */
snip = (char *)GC_malloc(diff + 1);
strncat(snip, text, diff);
printf("%s\n", snip);
}
/* The next char is a space or '[' or ']'. */
if ('[' == rest[0] || ']' == rest[0]) {
printf("%c\n", rest[0]);
}
/* */
text = trim_leading_blanks(++rest);
/*printf(">>>%s\n\n", text);*/
/* calling strpbrk on NULL caused segfault! */
rest = (NULL != text) ? strpbrk(text, " []") : text;
}
if (text) {
printf("%s\n", text);
}
}