Don't hide unexpected token error in case of no matches

Author: vojtech-dobes

src/GrammarProcessing/LexicalGrammar.php

@@ -42,10 +42,6 @@ public function parseSource(string $source): TokenStream
 			throw new UnexpectedTokenException("Can't parse source: " . preg_last_error_msg(), null);
 		}
 
-		if ($matches === []) {
-			return new TokenStream([]);
-		}
-
 		$getLocation = function (int $offset) use ($source): Location {
 			$precedingText = substr($source, 0, $offset);
 
@@ -76,6 +72,10 @@ public function parseSource(string $source): TokenStream
 			);
 		}
 
+		if ($matches === []) {
+			return new TokenStream([]);
+		}
+
 		if ($this->ignoredTokenSymbols !== []) {
 			if (count($this->ignoredTokenSymbols) === 1) {
 				$matches = array_values(