ソースコード：Map(params object[])

静的メソッド Map が、組み込み関数 map に相当します。

# IronPython-1.1.2/Src/IronPython/Modules/Builtin.cs

    [PythonType("__builtin__")]

    public static partial class Builtin {

        ...

        [PythonName("map")]

        public static List Map(params object[] param) {

            if (param == null || param.Length < 2) {

                throw Ops.TypeError("at least 2 arguments required to map");

            }

            List ret = new List();

            object func = param[0];

            if (param.Length == 2) {

                IEnumerator i = Ops.GetEnumerator(param[1]);

                while (i.MoveNext()) {

                    if (func == null) ret.AddNoLock(i.Current);

                    else ret.AddNoLock(Ops.Call(func, i.Current));

                }

                return ret;

            } else {

                IEnumerator[] enums = new IEnumerator[param.Length - 1];

                for (int i = 0; i < enums.Length; i++) {

                    enums[i] = Ops.GetEnumerator(param[i + 1]);

                }
                object[] args = new object[enums.Length];

                while (true) {

                    bool done = true;

                    for (int i = 0; i < enums.Length; i++) {

                        if (enums[i].MoveNext()) {

                            args[i] = enums[i].Current;

                            done = false;

                        } else {

                            args[i] = null;

                        }

                    }

                    if (done) {

                        return ret;

                    }

                    if (func != null) {

                        ret.AddNoLock(Ops.Call(func, args));

                    } else {

                        ret.AddNoLock(Tuple.MakeTuple(args));

                        args = new object[enums.Length];    // Tuple does not copy the array, allocate new one.

                    }

                }

            }

        }