LanguageFeatures/Patterns/logical_or_A05_t04.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 logicalOrPattern ::= ( logicalOrPattern '||' )? logicalAndPattern
///
/// A pair of patterns separated by || matches if either of the branches match
///
/// A logical-or pattern may match even if one of its branches does not. That
/// means that any variables in the non-matching branch would not be
/// initialized. To avoid problems stemming from that, the following
/// restrictions apply:
///
/// The two branches must define the same set of variables.
///
/// If the left branch matches, the right branch is not evaluated. This
/// determines which value the variable gets if both branches would have
/// matched. In that case, it will always be the value from the left branch.
///
/// @description Checks that if the left branch doesn't match, then the right
/// branch is evaluated. Test if-case statement
/// @author sgrekhov22@gmail.com

import "patterns_lib.dart";
import "../../Utils/expect.dart";

String log = "";

void logger(String toLog) {
  log += toLog;
}

void clearLog() {
  log = "";
}

main() {
  const zero = Unit(0, logger);
  const one = Unit(1, logger);
  const two = Unit(2, logger);
  const three = Unit(3, logger);
  const pi = Unit(3.14, logger);

  Shape shape1 = Square(1, logger);
  if (shape1 case Square(area: two) || Square(area: one)) {
    Expect.equals("Square.area:(2==1);(1==1);", log);
  } else {
    Expect.fail("Expression should match");
  }
  clearLog();

  Shape shape2 = Shape(logger);
  if (shape2 case Square(area: two) || Rectangle(area: one)
      || Shape(area: zero)) {
    Expect.equals("Shape.area:(0==0);", log);
  } else {
    Expect.fail("Expression should match");
  }
  clearLog();

  Shape shape3 = Circle(1, logger);
  if (shape3 case Circle(area: two) || Circle(area: one) || Circle(area: zero)
      || Circle(area: pi)) {
    Expect.equals("Circle.area:(2==3.14);(1==3.14);(0==3.14);(3.14==3.14);",
      log);
  } else {
    Expect.fail("Expression should match");
  }
  clearLog();

  Shape shape4 = Rectangle(1, 2, logger);
  if (shape4 case Rectangle(area: three) || Rectangle(area: one)
      || Rectangle(area: pi)) {
    Expect.fail("No branches should match");
  } else {
    Expect.equals("Rectangle.area:(3==2);(1==2);(3.14==2);", log);
  }
}