Function flatMap

test/fixtures/snapshot/typescript.js:698–714

* Maps an array. If the mapped value is an array, it is spread into the result. * * @param array The array to map. * @param mapfn The callback used to map the result into one or more values.

(array, mapfn)

     * @param mapfn The callback used to map the result into one or more values.
     */
    function flatMap(array, mapfn) {
        var result;
        if (array) {
            for (var i = 0; i < array.length; i++) {
                var v = mapfn(array[i], i);
                if (v) {
                    if (isArray(v)) {
                        result = addRange(result, v);
                    }
                    else {
                        result = append(result, v);
                    }
                }
            }
        }
        return result || ts.emptyArray;
    }
    ts.flatMap = flatMap;
    function flatMapToMutable(array, mapfn) {
        var result = [];