dart / co19 / e277bf38f0617681bff9ae74ce7d4e3235757672 / . / Language / Interfaces / Superinterfaces / Inheritance_and_Overriding / inheritance_t01.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 We define inherited(J, K) to be | |

/// the set of members m such that all of the following hold: | |

/// • m is accessible to K and | |

/// • A is a direct superinterface of J and either | |

/// – A declares a member m or | |

/// – m is a member of inherited(A, K). | |

/// • m is not overridden by J. | |

/// ... | |

/// Otherwise, if the static types T1,...,Tk of the members m1,...,mk are not | |

/// identical, then there must be a member mx such that Tx <: Ti, 1 ≤ x ≤ k for | |

/// all i ∈ 1..k, or a static type warning occurs. The member that is inherited | |

/// is mx, if it exists; otherwise: let numberOf P ositionals(f) denote the | |

/// number of positional parameters of a function f, and let numberOf | |

/// RequiredParams(f) denote the number of required parameters of a function f. | |

/// Furthermore, let s denote the set of all named parameters of the m1,...,mk. | |

/// Then let | |

/// h = max(numberOf Positionals(mi)), | |

/// r = min(numberOf RequiredParams(mi)), i ∈ 1..k. | |

/// Then I has a method named n, with r required parameters of type dynamic, | |

/// h positional parameters of type dynamic, named parameters s of type dynamic | |

/// and return type dynamic. | |

/// @description Checks that if two methods with the same name but different | |

/// parameters are inherited then it is a compile error | |

/// @author sgrekhov@unipro.ru | |

class A {} | |

class B extends A {} | |

class C {} | |

class D extends C {} | |

abstract class SI1 { | |

void foo(A v1, D v2); | |

} | |

abstract class SI2 { | |

void foo(B v1, C v2); | |

} | |

abstract class I implements SI1, SI2 {} | |

// ^ | |

// [analyzer] unspecified | |

// [cfe] unspecified | |

main() { | |

I? i = null; | |

} |