Language/15_Types/5_Function_Types_A01_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. For all i 1 <= i <= n, Ti <=> Si.
 * @description Checks that this statement is true for function types with no arguments: 
 * S is some type, T is some other type assignable to S.
 * @author iefremov
 * @reviewer rodionov
 */
import "../../Utils/expect.dart";

typedef returnsDynamic();
typedef Object returnsObject();
typedef num returnsNum();

  //() -> T is () -> dynamic
void f1() {}
int f2() {}
String f3() {}
double f4() {}
Object f5() {}
returnsDynamic f6() {}
List f7() {}
List<int> f8() {}
Map<int, List<List<List>>> f9() {}
  //() -> T is () -> Object
int f10() {}
String f11() {}
double f12() {}
Object f13() {}
List f14() {}
List<int> f15() {}
Map<int, List<List<List>>> f16() {}
  //() -> T is () -> num
int f17() {}
double f18() {}
num f19() {}

main() {
  //() -> T is () -> dynamic
  Expect.isTrue(f1 is returnsDynamic);
  Expect.isTrue(f2 is returnsDynamic);
  Expect.isTrue(f3 is returnsDynamic);
  Expect.isTrue(f4 is returnsDynamic);
  Expect.isTrue(f5 is returnsDynamic);
  Expect.isTrue(f6 is returnsDynamic);
  Expect.isTrue(f7 is returnsDynamic);
  Expect.isTrue(f8 is returnsDynamic);
  Expect.isTrue(f9 is returnsDynamic);

  //() -> T is () -> Object
  Expect.isTrue(f10 is returnsObject);
  Expect.isTrue(f11 is returnsObject);
  Expect.isTrue(f12 is returnsObject);
  Expect.isTrue(f13 is returnsObject);
  Expect.isTrue(f14 is returnsObject);
  Expect.isTrue(f15 is returnsObject);
  Expect.isTrue(f16 is returnsObject);

  //() -> T is () -> num
  Expect.isTrue(f17 is returnsNum);
  Expect.isTrue(f18 is returnsNum);
  Expect.isTrue(f19 is returnsNum);
}