# ICU string `UChar *` which are UTF-16 strings
extern class UCharString `{ UChar *`}

	# Returns an empty `UCharString` of length `length`
	new empty (length: Int) `{
		UChar * str = (UChar *)malloc(sizeof(UChar) * length);
		u_memset(str, 0, length);
		return str;
	`}

	# Returns a `NULL` `UCharString`
	new nul `{ return NULL; `}

	# Returns the number of code points up to `code_units` characters
	fun code_points(code_units: Int): Int `{
		if (self == NULL) {
			return -1;
		}
		return u_countChar32(self, code_units);
	`}

	# Converts a `CString` to a `UCharString` and returns the required length of said `UCharString`
	fun from_cstring(dest_length: Int, source: CString, source_length: Int): Int `{
		UErrorCode error = U_ZERO_ERROR;
		int32_t res;
		u_strFromUTF8(self, dest_length, &res, source, source_length, &error);
		return res;
	`}

	# Converts `self` to a `CString` and returns the required length (without the termination character) of said `CString`
	fun to_cstring(dest: CString, dest_length: Int, source_length: Int): Int `{
		UErrorCode error = U_ZERO_ERROR;
		int32_t res;
		u_strToUTF8(dest, dest_length, &res, self, source_length, &error);
		return res;
	`}

	# Get code point at code unit `offset`
	fun char_at_offset(offset: Int, code_units: Int): Char `{
		UChar32 c = 0;
		U16_NEXT(self, offset, code_units, c);
		return c;
	`}
end