function maybeIdentifier(key) {
        var result = false,
            i;

        for (i = 0; i < key.length; i++) {
            result = Acorn.isIdentifierChar(key.charCodeAt(i));
            if (!result) {
                break;
            }
        }

        return result;
    }
Is the string key perhaps a valid JavaScript identifier?

@param {string} key - string to test.
@return {boolean} - could key be a valid identifier?