ableos/sysdata/libraries/stn/src/string.hb

length := fn(ptr: ^u8): uint {
	len := 0
	loop if *(ptr + len) == 0 return len else len += 1
}

display_int := fn(num: int, p: ^u8, radix: uint): ^u8 {
	ptr := p
	negative := num < 0
	if negative {
		num = -num
	}

	if radix == 2 {
		*ptr = 48
		ptr += 1;
		*ptr = 98
		ptr += 1
	} else if radix == 16 {
		*ptr = 48
		ptr += 1;
		*ptr = 120
		ptr += 1
	} else if radix == 8 {
		*ptr = 48
		ptr += 1;
		*ptr = 111
		ptr += 1
	}
	digits_start := ptr
	if num == 0 {
		*ptr = 48
		ptr += 1
	} else {
		loop if num == 0 break else {
			digit := num % @bitcast(radix)
			if digit < 10 {
				*ptr = @intcast(digit) + 48
			} else {
				*ptr = @intcast(digit) + 55
			}
			ptr += 1
			num /= @bitcast(radix)
		}
	}

	if negative {
		*ptr = 45
		ptr += 1
	};

	*ptr = 0

	@inline(reverse, digits_start)

	return p
}

reverse := fn(s: ^u8): void {
	i := 0
	j := @inline(length, s) - 1
	temp := @as(u8, 0)
	loop if i >= j break else {
		temp = *(s + i);
		*(s + i) = *(s + j);
		*(s + j) = temp
		i += 1
		j -= 1
	}
	return
}

equals := fn(lhs: ^u8, rhs: ^u8): bool {
	if lhs == rhs {
		return true
	}
	i := 0
	loop if *(lhs + i) != *(rhs + i) {
		return false
	} else if *lhs == 0 {
		return true
	} else {
		i += 1
	}
}

contains := fn(haystack: ^u8, needle: ^u8): bool {
	haystack_len := @inline(length, haystack)
	needle_len := @inline(length, needle)

	if needle_len == 0 {
		return true
	}
	if haystack_len < needle_len {
		return false
	}

	max_start := haystack_len - needle_len

	pos := 0
	loop if pos > max_start break else {
		is_match := true
		offset := 0

		loop if offset >= needle_len break else {
			if *(haystack + pos + offset) != *(needle + offset) {
				is_match = false
			}
			if is_match == false {
				break
			}
			offset += 1
		}

		if is_match {
			return true
		}
		pos += 1
	}

	return false
}