tag name can end with ? like {foo?}

Author: dg

src/Latte/Compiler/TemplateLexer.php

@@ -94,7 +94,7 @@ private function stateLatteTag(): array
 	{
 		$tokens[] = $this->match('~
 			(?<Slash>/)?
-			(?<Latte_Name> = | _(?!_) | [a-z]\w*+(?:[.:-]\w+)*+(?!::|\(|\\\))?   # name, /name, but not function( or class:: or namespace\
+			(?<Latte_Name> = | _(?!_) | [a-z]\w*+(?:[.:-]\w+)*+\??(?!::|\(|\\\))?   # name, /name, but not function( or class:: or namespace\
 		~xsiAu');
 
 		$tokens[] = $this->tagLexer->tokenizePartially($this->input, $this->position);

tests/common/Compiler.samples.phpt

@@ -103,3 +103,11 @@ Assert::contains(
 	'escapeHtmlText(My\Class::foo)',
 	$latte->compile('{My\Class::foo}'),
 );
+
+
+// allowed ? in name
+Assert::exception(
+	fn() => $latte->compile('{foo?}'),
+	Latte\CompileException::class,
+	'Unexpected tag {foo?} (on line 1 at column 1)',
+);