Function parseForStatement

lib/assets/javascripts/JSXTransformer.js:7513–7603

(opts)

    }

    function parseForStatement(opts) {
        var init, test, update, left, right, body, operator, oldInIteration,
            marker = markerCreate();
        init = test = update = null;
        expectKeyword('for');

        // http://wiki.ecmascript.org/doku.php?id=proposals:iterators_and_generators&s=each
        if (matchContextualKeyword('each')) {
            throwError({}, Messages.EachNotAllowed);
        }

        expect('(');

        if (match(';')) {
            lex();
        } else {
            if (matchKeyword('var') || matchKeyword('let') || matchKeyword('const')) {
                state.allowIn = false;
                init = parseForVariableDeclaration();
                state.allowIn = true;

                if (init.declarations.length === 1) {
                    if (matchKeyword('in') || matchContextualKeyword('of')) {
                        operator = lookahead;
                        if (!((operator.value === 'in' || init.kind !== 'var') && init.declarations[0].init)) {
                            lex();
                            left = init;
                            right = parseExpression();
                            init = null;
                        }
                    }
                }
            } else {
                state.allowIn = false;
                init = parseExpression();
                state.allowIn = true;

                if (matchContextualKeyword('of')) {
                    operator = lex();
                    left = init;
                    right = parseExpression();
                    init = null;
                } else if (matchKeyword('in')) {
                    // LeftHandSideExpression
                    if (!isAssignableLeftHandSide(init)) {
                        throwError({}, Messages.InvalidLHSInForIn);
                    }
                    operator = lex();
                    left = init;
                    right = parseExpression();
                    init = null;
                }
            }

            if (typeof left === 'undefined') {
                expect(';');
            }
        }