Function parseArrayInitialiser

lib/assets/javascripts/JSXTransformer.js:5315–5375

()

    // 11.1.4 Array Initialiser

    function parseArrayInitialiser() {
        var elements = [], blocks = [], filter = null, tmp, possiblecomprehension = true,
            marker = markerCreate();

        expect('[');
        while (!match(']')) {
            if (lookahead.value === 'for' &&
                    lookahead.type === Token.Keyword) {
                if (!possiblecomprehension) {
                    throwError({}, Messages.ComprehensionError);
                }
                matchKeyword('for');
                tmp = parseForStatement({ignoreBody: true});
                tmp.of = tmp.type === Syntax.ForOfStatement;
                tmp.type = Syntax.ComprehensionBlock;
                if (tmp.left.kind) { // can't be let or const
                    throwError({}, Messages.ComprehensionError);
                }
                blocks.push(tmp);
            } else if (lookahead.value === 'if' &&
                           lookahead.type === Token.Keyword) {
                if (!possiblecomprehension) {
                    throwError({}, Messages.ComprehensionError);
                }
                expectKeyword('if');
                expect('(');
                filter = parseExpression();
                expect(')');
            } else if (lookahead.value === ',' &&
                           lookahead.type === Token.Punctuator) {
                possiblecomprehension = false; // no longer allowed.
                lex();
                elements.push(null);
            } else {
                tmp = parseSpreadOrAssignmentExpression();
                elements.push(tmp);
                if (tmp && tmp.type === Syntax.SpreadElement) {
                    if (!match(']')) {
                        throwError({}, Messages.ElementAfterSpreadElement);
                    }
                } else if (!(match(']') || matchKeyword('for') || matchKeyword('if'))) {
                    expect(','); // this lexes.
                    possiblecomprehension = false;
                }
            }
        }

        expect(']');

        if (filter && !blocks.length) {
            throwError({}, Messages.ComprehensionRequiresBlock);
        }

        if (blocks.length) {
            if (elements.length !== 1) {
                throwError({}, Messages.ComprehensionError);
            }
            return markerApply(marker, delegate.createComprehensionExpression(filter, blocks, elements[0]));