LanguageFeatures/Records/static_semantics_A02_t01.lib.dart

// Copyright (c) 2022, 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 shape to mean the number of positional fields (the
/// record's arity) and the set of names of its named fields. Record types are
/// structural, not nominal. Records produced in unrelated libraries have the
/// exact same static type if they have the same shape and their corresponding
/// fields have the same types.
///
/// The order of named fields is not significant. The record types {int a,
/// int b} and {int b, int a} are identical to the type system and the runtime.
/// (Tools may or may not display them to users in a canonical form similar to
/// how they handle function typedefs.)
///
/// @description Checks that records produced in unrelated libraries have the
/// exact same static type if they have the same shape and their corresponding
/// fields have the same types.
/// @author sgrekhov22@gmail.com

library static_semantics_A02_t01_lib;

typedef T1 = (int, String);
typedef T2 = (int i, {String s});
typedef T3 = ({int i, String s});

T1 t1 = (42, "Lily was here");
T2 t2 = (0, s: "");
T3 t3 = (i: 1, s: "Hello");