import QtQuick

Item {
function f(){
        (function() {}()) // this is fine
         function() {}() // can't be parsed: Expected token `identifier'
    }
}

StatementListItem: ExpressionStatementLookahead T_FORCE_DECLARATION Declaration Semicolon;
/.
    case $rule_number: {
        sym(1).Node = new (pool) AST::StatementList(sym(3).FunctionDeclaration);
    } break;
./

-- Spec says it should have a "[lookahead ∉ { {, function, class, let [ }]" before the Expression statement.
-- This is implemented with the rule below that is run before any statement and inserts a T_EXPRESSION_STATEMENT_OK
-- token if it's ok to parse as an expression statement.
ExpressionStatementLookahead: ;
/:
#define J_SCRIPT_EXPRESSIONSTATEMENTLOOKAHEAD_RULE $rule_number
:/
/.
    case $rule_number: {
        int token = lookaheadToken(lexer);
        if (token == T_LBRACE)
            pushToken(T_FORCE_BLOCK);
        else if (token == T_FUNCTION || token == T_CLASS || token == T_LET || token == T_CONST)
            pushToken(T_FORCE_DECLARATION);
    } break;
./