Implement String structure and update Location/Token to use it

v0/token.c

@@ -93,13 +93,14 @@ static size_t get_line_length(const char* line_start) {
 static Token create_token(TokenStream* ts, TokenType type, const char* text, size_t length, int line, int column, const char* line_start) {
 	Token t;
 	t.token = type;
-	t.text = (char*)text;
-	t.text_length = length;
+	t.text.data = (char*)text;
+	t.text.length = length;
 	t.location.filename = (char*)ts->filename;
 	t.location.line = line;
-	t.location.column = column;
-	t.location.line_text = (char*)line_start;
-	t.location.line_text_length = get_line_length(line_start);
+	t.location.column_start = column;
+	t.location.column_end = column + (int)length - 1;
+	t.location.line_text.data = (char*)line_start;
+	t.location.line_text.length = get_line_length(line_start);
 	return t;
 }
 
@@ -192,6 +193,6 @@ Token tokenstream_next(TokenStream* ts) {
 
 	/* Unknown character */
 	Token t = create_token(ts, TOKEN_UNKNOWN, start_text, 1, start_line, start_column, line_start);
-	log_on_line(&t.location, t.location.column, "unexpected token '%c'", c);
+	log_on_line(&t.location, t.location.column_end, "unexpected token '%c'", c);
 	return t;
 }