public void UnionWithT4_UsesElseExpressionIfNoCase3Match()
 {
     var union = new Union<int, string, Colors, Animals>(Animals.Cow);
     var result = union.Match<bool>()
                       .Case1().Do(x => false).Case2().Do(x => false).Case3().Do(false).Else(true).Result();
     IsTrue(result);
 }

 public void UnionWithT3_UsesElseIfNoCase3Match()
 {
     var union = new Union<int, string, Colors, Animals>(Colors.Green);
     var result = union.Match<bool>()
                       .Case1().Do(x => false).Case2().Do(x => false).Case4().Do(false).Else(x => true).Result();
     IsTrue(result);
 }

 public static string YesNo123OrOtherIntMatcherExample(Union<int, bool> value) => 
     value.Match<string>()
          .Case1().Of(1).Or(2).Or(3).Do(i => $"{i} in range 1-3")
          .Case1().Do(i => $"int={i}")
          .Case2().Of(true).Do("Yes")
          .Case2().Of(false).Do("No")
          .Result();

 public void DifferentT3Values_ArentEqual()
 {
     var a = new Union<int, string, Colors, Animals>(Colors.Blue);
     var b = new Union<int, string, Colors, Animals>(Colors.Red);
     IsFalse(a.Equals(b));
     IsFalse(a == b);
 }

 public void UnionWithT1_MatchesBasicCase1CorrectlyWithExec()
 {
     var union = new Union<int, string>(2);
     var result = 0;
     union.Match().Case1().Do(x => result = x).Case2().Do(x => result = 3).Exec();
     AreEqual(2, result);
 }

 public void UnionWithT1_UsesCase1MatchOverElse()
 {
     var union = new Union<int, string, Colors, Animals>(2);
     var result = 0;
     union.Match().Case1().Do(x => result = x).Else(_ => result = 1).Exec();
     AreEqual(2, result);
 }

 public void DifferentT3Values_ArentEqual()
 {
     var a = new Union<int, string, Colors>(Colors.Blue);
     var b = new Union<int, string, Colors>(Colors.Green);
     IsFalse(a.Equals(b));
     IsTrue(a != b);
 }

 public static ReactStyle FontSize(Union<string, int> fontSize)
 {
     return new ReactStyle
     {
         FontSize = fontSize
     };
 }

        static void Main(string[] args)
        {
            string s = "123";
            int i;
            if (int.TryParse(s, out i))
            {
                Console.WriteLine("Parsed {0}", i);
            }
            else
            {
                Console.WriteLine("Unable to parse '{0}'", s);
            }

            s = "1234zr";
            s.ParseInt()
                .Match()
                .None()
                    .Do(() => Console.WriteLine($"Unable to parse '{s}'"))
                .Some()
                    .Do(value => Console.WriteLine($"Parsed {value}"))
                .Exec();

            var demoUnion = new Union<int, bool>(false);
            string matcherResult = demoUnion.Match<string>()
                 .Case1().Of(1).Or(2).Or(3).Do(ui => $"{ui} in range 1-3")
                 .Case1().Do(ui => $"int={ui}")
                 .Case2().Of(true).Do("Yes")
                 .Case2().Of(false).Do("No")
                 .Result();
            Console.WriteLine(matcherResult);
        }

 public void UnionWithT2_UsesCase2MatchOverElse()
 {
     var union = new Union<int, string, Colors, Animals>("x");
     var result = 0;
     union.Match().Case2().Do(_ => result = 1).Else(_ => result = 2).Exec();
     AreEqual(1, result);
 }

 public void DifferentT2Values_ArentEqual()
 {
     var a = new Union<int, string, Colors>("abc");
     var b = new Union<int, string, Colors>("def");
     IsFalse(a.Equals(b));
     IsTrue(a != b);
 }

 public void UnionWithT2_UsesElseIfNoCase2MatchWithExec()
 {
     var union = new Union<int, string, Colors>("fred");
     var result = 0;
     union.Match().Case1().Do(x => result = 1).Case3().Do(x => result = 3).Else(x => result = 2).Exec();
     AreEqual(2, result);
 }

 public void UnionWithT2_CaseOfExpressionSupported()
 {
     var union = new Union<int, string, Colors, Animals>("1");
     var result = union.Match<int>()
                       .Case1().Do(0).Case2().Of("1").Do(2).Case2().Do(1).Case3().Do(3).Case4().Do(4).Result();
     AreEqual(2, result);
 }

 public void UnionWithT1_UsesElseIfNoCase1MatchWithExec()
 {
     var union = new Union<int, string, Colors>(11);
     var result = 0;
     union.Match().Case2().Do(x => result = 1).Case3().Do(x => result = 3).Else(x => result = x.Case1).Exec();
     AreEqual(11, result);
 }

 public void UnionWithT3_UsesCase3MatchOverElse()
 {
     var union = new Union<int, string, Colors, Animals>(Colors.Blue);
     var result = 0;
     union.Match().Case3().Do(_ => result = 1).Else(_ => result = 3).Exec();
     AreEqual(1, result);
 }

 public void DifferentT4Values_ArentEqual()
 {
     var a = new Union<int, string, Colors, Animals>(Animals.Cat);
     var b = new Union<int, string, Colors, Animals>(Animals.Cow);
     IsFalse(a.Equals(b));
     IsFalse(a == b);
 }

 public void ComparingT2ValueWithNull_ResultsInNotEqual()
 {
     var a = new Union<int, string>(null);
     IsFalse(a.Equals(null));
     IsTrue(a != null);
     IsTrue(null != a);
 }

 public void DifferentT2Values_ArentEqual()
 {
     var a = new Union<int, string>("a");
     var b = new Union<int, string>("b");
     IsFalse(a.Equals(b));
     IsTrue(a != b);
 }

 public void UnionWithT4_UsesCase4MatchOverElse()
 {
     var union = new Union<int, string, Colors, Animals>(Animals.Sheep);
     var result = 0;
     union.Match().Case4().Do(_ => result = 1).Else(_ => result = 3).Exec();
     AreEqual(1, result);
 }

 public void UnionWithT3_SimpleCaseExpressionSupported()
 {
     var union = new Union<int, string, Colors, Animals>(Colors.Blue);
     var result = 0;
     union.Match().Case1().Do(_ => result = 1).Case2().Do(_ => result = 2)
                  .Case3().Do(_ => result = 3).Case4().Do(_ => result = 4).Exec();
     AreEqual(3, result);
 }