cutes/strutil.c

55 lines
1.4 KiB
C

#include "strutil.h"
#include "string.h"
uintptr_t strnhash(const char* s, size_t n) {
static const size_t shift = sizeof(uintptr_t) * 8 - 4;
uintptr_t hash = 0;
for(size_t i = 0; i < n; ++i) {
hash = ((hash << 4) | s[i]) ^ (((uintptr_t)0xF << shift) & hash);
}
return hash;
}
uintptr_t strhash(const char* s) {
return strnhash(s, strlen(s));
}
long strlast(const char* rbegin, const char* rend, char search) {
const char* itr = rbegin;
while(itr < rend && *itr != '\0')
if(*itr == search) return itr - rend;
else itr--;
return -1;
}
long strfirst(const char* begin, const char* end, char search) {
const char* itr = begin;
while(itr < end && *itr != '\0')
if(*itr == search) return itr - begin;
else itr++;
return -1;
}
long strcount(const char* begin, const char* end, char search) {
long count = 0;
for(;begin < end && *begin != '\0'; ++begin)
if(*begin == search) ++count;
return count;
}
long strfirst_pred(const char* begin, const char* end, CharPredFn pred) {
const char* itr = begin;
while(itr < end && *itr != '\0')
if(pred(*itr)) return itr - begin;
else itr++;
return -1;
}
long strlast_pred(const char* rbegin, const char* rend, CharPredFn pred) {
const char* itr = rbegin;
while(itr < rend && *itr != '\0')
if(pred(*itr)) return itr - rend;
else itr--;
return -1;
}