Ivar Fatland
44 lines
845 B
C
44 lines
845 B
C
#include <stddef.h>
|
|
|
|
#include "str.h"
|
|
|
|
static bool intToIndex(String string, int i, size_t *out_index) {
|
|
int val = 0;
|
|
bool is_ok = true;
|
|
if (i >= 0) {
|
|
val = i;
|
|
} else {
|
|
val = string.size + 1 + i;
|
|
}
|
|
|
|
if (val < 0) {
|
|
val = 0;
|
|
is_ok = false;
|
|
} else if (val > string.size) {
|
|
val = string.size;
|
|
is_ok = false;
|
|
}
|
|
|
|
*out_index = val;
|
|
return is_ok;
|
|
}
|
|
|
|
bool StringSub(String string, int start, int end, String *out_substr) {
|
|
|
|
size_t start_index = 0;
|
|
bool start_ok = intToIndex(string, start, &start_index);
|
|
size_t end_index = 0;
|
|
bool end_ok = intToIndex(string, end, &end_index);
|
|
|
|
if (string.size == 0 || start_index >= end_index) {
|
|
out_substr->size=0;
|
|
out_substr->buffer=NULL;
|
|
return false;
|
|
}
|
|
|
|
out_substr->buffer = &string.buffer[start_index];
|
|
out_substr->size = end_index - start_index;
|
|
|
|
return start_ok && end_ok;
|
|
}
|