Language/Types/Function_Types/subtype_optional_args_t03.dart

// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

/**
 * @assertion A function type (T1,...Tk,[Tk+1,...,Tn+m]) -> T is a subtype of
 * the function type (S1,...,Sk+j,[Sk+j+1,...,Sn]) -> S, if all of the following
 * conditions are met:
 * 1. Either
 *    • S is void, or
 *    • T <=> S.
 * 2. ∀i ∈ 1..n, Ti ⇐⇒ Si.
 * @description Checks that this statement is true even if the subtype function
 * type has more positional optional parameters than the supertype as long as the
 * supertype's positional optional parameters match the beginning of the list of
 * subtype's positional optional parameters.
 * @author iefremov
 */
import "../../../Utils/expect.dart";

class A {}
class A1 {}
class A2 {}
class B implements A, A1, A2 {}
class C implements B {}
class D implements C {}

class G<T, S, U, W> {}

typedef classesFunc(A aa, [A? a, B? b, C? c, D? d]);
typedef genericsFunc([Map<num, int>? m, List<List<B>>? l, G<A, B, C, D>? g]);
typedef dynamicFunc([var x, var y, var z, var v]);
typedef funcFunc([classesFunc? f1, genericsFunc? f2, dynamicFunc? f3]);
typedef mixFunc([var x, B? b, G<A, B, C, D>? g, funcFunc? f]);

typedef okWithClassesFunc_1(A aa, [A? a, A1? b, A1? c, A1? d]);
typedef okWithClassesFunc_2(A aa, [D? a, D? b, D? c, D? d]);

typedef okWithGenericsFunc_1(
    [Map<num, num>? m, List<List<A1>>? l, G<A, A1, A1, A1>? g]);
typedef okWithGenericsFunc_2(
    [Map<int, int>? m, List<List<D>>? l, G<D, D, D, D>? g]);

typedef okWithDynamicFunc_1([A? x, G? y, mixFunc z, var v]);
typedef okWithDynamicFunc_2([int? x, bool? y, List<Map>? z, classesFunc? v]);


main() {
  Expect.isFalse((var vv, [D? a, B? b, C? c, A? d, var xx, Map? xxx, Object? xxxx]) {} is classesFunc);

  Expect.isTrue(([var m, var l, var g, var xx, var xxx, var xxxx]) {} is genericsFunc);

  Expect.isFalse(
          ([A? x, G? y, mixFunc? z, var v, Object? xx, List<Map<int, mixFunc>>? xxx, mixFunc? xxxx]) {} is dynamicFunc);

  Expect.isTrue(
          ([okWithClassesFunc_2? f1, okWithGenericsFunc_2? f2, okWithDynamicFunc_2? f3, mixFunc? xx, funcFunc? xxx]) {} is funcFunc);
}