Function parseForStatement

scripts/libs/esprima.js:3442–3534

(node)

    }

    function parseForStatement(node) {
        var init, test, update, left, right, kind, declarations,
            body, oldInIteration, previousAllowIn = state.allowIn;

        init = test = update = null;

        expectKeyword('for');

        expect('(');

        if (match(';')) {
            lex();
        } else {
            if (matchKeyword('var')) {
                init = new Node();
                lex();

                state.allowIn = false;
                init = init.finishVariableDeclaration(parseVariableDeclarationList());
                state.allowIn = previousAllowIn;

                if (init.declarations.length === 1 && matchKeyword('in')) {
                    lex();
                    left = init;
                    right = parseExpression();
                    init = null;
                } else {
                    expect(';');
                }
            } else if (matchKeyword('const') || matchKeyword('let')) {
                init = new Node();
                kind = lex().value;

                state.allowIn = false;
                declarations = parseBindingList(kind, {inFor: true});
                state.allowIn = previousAllowIn;

                if (declarations.length === 1 && declarations[0].init === null && matchKeyword('in')) {
                    init = init.finishLexicalDeclaration(declarations, kind);
                    lex();
                    left = init;
                    right = parseExpression();
                    init = null;
                } else {
                    consumeSemicolon();
                    init = init.finishLexicalDeclaration(declarations, kind);
                }
            } else {
                state.allowIn = false;
                init = parseExpression();
                state.allowIn = previousAllowIn;

                if (matchKeyword('in')) {
                    // LeftHandSideExpression
                    if (!isLeftHandSide(init)) {
                        tolerateError(Messages.InvalidLHSInForIn);
                    }