Language/Types/Function_Types/subtype_named_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 The function type (T1, ... Tn, {Tx1 x1, ..., Txk xk}) -> T is a
 * subtype of the function type (S1, ..., Sn, {Sy1 y1, ..., Sym ym }) -> S, if
 * all of the following conditions are met:
 * 1. Either
 *    • S is void, Or
 *    • T ⇐⇒ S.
 * 2. ∀i ∈ 1..n, Ti ⇐⇒ Si .
 * 3. k ≥ m and yi ∈ {x1 , ..., xk }, i ∈ 1..m.
 * 4. For all yi ∈ {y1 , ..., ym }, yi = xj ⇒ Tj ⇐⇒ Si.
 * @description Checks that this statement is true even if the subtype function
 * type has more named optional parameters than the supertype as long it's a
 * superset of the supertype's named optional parameters.
 * @author rodionov
 */
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(A aa, {D? a, D? b, D? c, D? d});
typedef okWithGenericsFunc({Map<int, int>? m, List<List<D>>? l, G<D, D, D, D>? g});
typedef okWithDynamicFunc({int? x, bool? y, List<Map>? z, classesFunc? v});


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

  Expect.isTrue(({List<List<B>>? l, Map<num, int>? m, G<A, B, C, D>? g}) {} is genericsFunc);

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

  Expect.isTrue(({okWithClassesFunc? f1, mixFunc? xx,
                  okWithDynamicFunc? f3, okWithGenericsFunc? f2}) {} is funcFunc);

}