src/Language/Parser.php
private function parseArray($isConst)
    {
        $start   = $this->lexer->token;
        $parseFn = $isConst ? function () {
            return $this->parseConstValue();
        } : function () {
            return $this->parseVariableValue();
        };

        return new ListValueNode(
            [
                'values' => $this->any(Token::BRACKET_L, $parseFn, Token::BRACKET_R),
                'loc'    => $this->loc($start),
            ]
        );
    }
private function parseArray($isConst)
    {
        $start   = $this->lexer->token;
        $parseFn = $isConst ? function () {
            return $this->parseConstValue();
        } : function () {
            return $this->parseVariableValue();
        };

        return new ListValueNode(
            [
                'values' => $this->any(Token::BRACKET_L, $parseFn, Token::BRACKET_R),
                'loc'    => $this->loc($start),
            ]
        );
    }
@param bool $isConst

@return ListValueNode