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 {
	is_negative := num < 0
	if is_negative num = -num

	ptr := p

	if num == 0 {
		*ptr = 0x30;
		*(ptr + 1) = 0
		return p
	}

	loop if num == 0 break else {
		remainder := num % @bitcast(radix)
		num /= @bitcast(radix);
		*ptr = @intcast(remainder + 0x30)
		if remainder > 9 {
			*ptr = @intcast(remainder - 10 + 0x41)
		}
		ptr += 1
	}

	if is_negative {
		*ptr = 0x2D
		ptr += 1
	}
	// ! it gets broked when you do this ??
	// *ptr = 0

	@inline(reverse, p)
	return p
}

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

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

clear := fn(ptr: ^u8): void {
	loop if *ptr == 0 break else {
		*ptr = 0
		ptr += 1
	}
}

split_once := fn(haystack: ^u8, needle: u8): ?^u8 {
	loop if *haystack == needle return haystack else if *haystack == 0 return null else haystack += 1
}

split_once_str := fn(haystack: ^u8, needle: ^u8): ?^u8 {
	if *needle == 0 return null

	loop if *haystack == 0 return null else {
		if *haystack == *needle {
			h := haystack
			n := needle

			loop {
				n += 1
				h += 1
				if *n == 0 {
					return haystack
				} else if *h == 0 | *h != *n {
					break
				}
			}
		}
		haystack += 1
	}
}

Split := struct {
	str: ^u8,
	needle: u8,
	done: bool,
}

split := fn(iter: ^u8, needle: u8): Split {
	return .(
		iter,
		needle,
		false,
	)
}

iter_split := fn(iter: ^Split): ?^u8 {
	if iter.done | *iter.str == 0 {
		return null
	}

	next := split_once(iter.str + 1, iter.needle)

	if next == null {
		iter.done = true
		return iter.str
	}
	s := iter.str
	iter.str = next + 1

	return s
}

SplitStr := struct {
	str: ^u8,
	needle: ^u8,
	done: bool,
}

split_str := fn(iter: ^u8, needle: ^u8): SplitStr {
	return .(
		iter,
		needle,
		false,
	)
}

iter_split_str := fn(iter: ^SplitStr): ?^u8 {
	if iter.done | *iter.str == 0 {
		return null
	}

	next := split_once_str(iter.str, iter.needle)

	if next == null {
		iter.done = true
		return iter.str
	}

	s := iter.str

	iter.str = next + length(iter.needle)

	return s
}

find_once := fn(haystack: ^u8, needle: u8): ?uint {
	return @bitcast(@inline(split_once, haystack, needle) - haystack)
}

find_once_str := fn(haystack: ^u8, needle: ^u8): ?uint {
	return @bitcast(@inline(split_once_str, haystack, needle) - haystack)
}

count := fn(haystack: ^u8, needle: ^u8): uint {
	c := 0
	loop if *haystack == needle {
		c += 1
		haystack += 1
	} else if *haystack == 0 return c else haystack += 1
}

count_str := fn(haystack: ^u8, needle: ^u8): uint {
	if *needle == 0 return 0
	c := 0
	loop if *haystack == 0 return c else {
		if *haystack == *needle {
			h := haystack
			n := needle

			loop {
				n += 1
				h += 1
				if *n == 0 {
					c += 1
					break
				} else if *h == 0 | *h != *n {
					break
				}
			}
		}
		haystack += 1
	}
}

left_trim := fn(str: ^u8, sub: ^u8): ^u8 {
	original := str
	if *str == *sub {
		loop if *sub == 0 {
			return str
		} else if *str != *sub {
			return original
		} else if *str == 0 {
			return original
		} else {
			str += 1
			sub += 1
		}
	}
	return str
}