LanguageFeatures/Spread-collections/TypeInference_A05_t08.dart

// Copyright (c) 2019, 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.

// @dart = 2.9

/// @assertion From the Unified collections Spec:
/// We require that at least one component unambiguously determine the literal
/// form, otherwise it is a compile-time error. So, given:
///    dynamic x = <int, int>{};
///    Iterable l = [];
///    Map m = {};
///    Then:
///    {...x}       // Static error, because it is ambiguous.
///    {...x, ...l} // Statically a set, runtime error when spreading x.
///    {...x, ...m} // Statically a map, no runtime error.
///    {...l, ...m} // Static error, because it must be both a set and a map.
/// @description Checks that {...?l, ...?m} is a static error
/// @author iarkh@unipro.ru


main() {
  Iterable l = [];
  Map m = {};

  var res1   = {...?l, ...m}; //# 01: compile-time error
  var res2   = {...m, ...?l}; //# 02: compile-time error
  List res3  = {...?l, ...m}; //# 03: compile-time error
  Map res4   = {...?l, ...m}; //# 04: compile-time error

  var res5   = {...l, ...?m}; //# 05: compile-time error
  var res6   = {...?m, ...l}; //# 06: compile-time error
  List res7  = {...l, ...?m}; //# 07: compile-time error
  Map res8   = {...l, ...?m}; //# 08: compile-time error

  var res9   = {...?l, ...?m}; //# 09: compile-time error
  var res10  = {...?m, ...?l}; //# 10: compile-time error
  List res11 = {...?l, ...?m}; //# 11: compile-time error
  Map res12  = {...?l, ...?m}; //# 12: compile-time error

}