public void Just()
{
var a = new object();
IMaybe <object> justA = Maybe.Just(a);
Assert.That(justA.Exists, Is.True);
Assert.That(a, Is.SameAs(justA.Value));
Assert.That(Maybe.Of(a), Is.EqualTo(justA));
Assert.That(justA.Equals(null), Is.False);
Assert.That(Maybe.Just(a), Is.EqualTo(justA));
Assert.That(Maybe.Just("b"), Is.Not.EqualTo(justA));
Assert.That(Maybe.Just <object>("b"), Is.Not.EqualTo(justA));
Assert.That(Maybe.Nothing <string>(), Is.Not.EqualTo(justA));
Assert.True(justA.Equals(justA));
Assert.That(Maybe.Just("a").ToString(), Is.EqualTo("Just(a)"));
Assert.That(justA.GetHashCode(), Is.EqualTo(justA.Value.GetHashCode()));
Assert.That(justA.GetOrElse(new object()), Is.SameAs(a));
bool called = false;
justA.GetOrElseGet(() =>
{
called = true;
return(new object());
});
Assert.That(called, Is.False);
}
public void Equality_IMaybeOfT()
{
IMaybe <int> a = Maybe.From(123);
IMaybe <int> b = Maybe.From(123);
IMaybe <int> c = Maybe.From(123);
IMaybe <int> d = Maybe.From(456);
IMaybe <string> e = Maybe.From("pretzels");
IMaybe <int> f = Maybe.Nothing <int>();
IMaybe <string> g = Maybe.Nothing <string>();
// reflexive
Assert.IsTrue(a.Equals(a));
// symmetric
Assert.IsTrue(a.Equals(b));
Assert.IsTrue(b.Equals(a));
// reflexive
Assert.IsTrue(a.Equals(b));
Assert.IsTrue(b.Equals(c));
Assert.IsTrue(a.Equals(c));
// inequality
Assert.IsFalse(a.Equals(d));
Assert.IsFalse(a.Equals(e));
Assert.IsFalse(a.Equals(f));
Assert.IsFalse(a.Equals(g));
// others
Assert.IsFalse(a.Equals(null));
Assert.IsFalse(a.Equals(new object()));
}
public void Equality_IMaybe()
{
IMaybe a = Maybe.From(typeof(int), 123);
IMaybe b = Maybe.From(typeof(int), 123);
IMaybe c = Maybe.From(typeof(int), 123);
IMaybe d = Maybe.From(typeof(int), 456);
IMaybe e = Maybe.From(typeof(string), "pretzels");
IMaybe f = Maybe.Nothing(typeof(int));
IMaybe g = Maybe.Nothing(typeof(string));
// reflexive
Assert.IsTrue(a.Equals(a));
// symmetric
Assert.IsTrue(a.Equals(b));
Assert.IsTrue(b.Equals(a));
// reflexive
Assert.IsTrue(a.Equals(b));
Assert.IsTrue(b.Equals(c));
Assert.IsTrue(a.Equals(c));
// inequality
Assert.IsFalse(a.Equals(d));
Assert.IsFalse(a.Equals(e));
Assert.IsFalse(a.Equals(f));
Assert.IsFalse(a.Equals(g));
// others
Assert.IsFalse(a.Equals(null));
Assert.IsFalse(a.Equals(new object()));
}
private static Stream <T> Calm <T>(Stream <T> sA, Lazy <IMaybe <T> > init)
{
return(sA.CollectLazy(init, (a, lastA) =>
{
IMaybe <T> ma = Maybe.Just(a);
return ma.Equals(lastA) ? (ReturnValue: Maybe.Nothing <T>(), State: lastA) : (ReturnValue: ma, State: ma);
}).FilterMaybe());
private static Stream <T> Calm <T>(Stream <T> sA, Lazy <IMaybe <T> > init)
{
return(sA.CollectLazy(init, (a, lastA) =>
{
IMaybe <T> ma = Maybe.Just(a);
return ma.Equals(lastA) ? Tuple.Create(Maybe.Nothing <T>(), lastA) : Tuple.Create(ma, ma);
}).FilterMaybe());
}
