public void BindFull()
{
Func <Func <Maybe <int> > > source = () =>
{
int n = 0;
return(() => n < 3 ? (Maybe <int>) new Maybe <int> .Some(n ++) : new Maybe <int> .None());
};
Func <string, int, Func <Func <Maybe <string> > > > repeat = (s, n) => () =>
{
int k = 0;
return(() => k++ < n ? (Maybe <string>) new Maybe <string> .Some(s) : new Maybe <string> .None());
};
var res = source.Bind(x => repeat(((char)('a' + x)).ToString(), x), (x, s) => s + x);
for (int i = 0; i < 2; i++)
{
var e = res();
Assert.IsTrue(e().Value == "b1", "Expected b1 (" + i + ")");
Assert.IsTrue(e().Value == "c2", "Expected c2 (" + i + ")");
Assert.IsTrue(e().Value == "c2", "Expected c2 again (" + i + ")");
Assert.IsTrue(e() is Maybe <string> .None, "Expected end (" + i + ")");
}
}
public void BindEmptyOuter()
{
Func <Func <Maybe <int> > > source = () => () => new Maybe <int> .None();
Func <Func <Maybe <string> > > some = () => () => new Maybe <string> .Some("");
var res = source.Bind(_ => some, (x, s) => s + x);
for (int i = 0; i < 2; i++)
{
var e = res();
Assert.IsTrue(e() is Maybe <string> .None, "Not empty (" + i + ")");
}
}
public void BindEmptyInner()
{
Func <Func <Maybe <int> > > source = () =>
{
int n = 0;
return(() => n == 0 ? (Maybe <int>) new Maybe <int> .Some(n ++) : new Maybe <int> .None());
};
Func <Func <Maybe <string> > > none = () => () => new Maybe <string> .None();
var res = source.Bind(_ => none, (x, s) => s + x);
for (int i = 0; i < 2; i++)
{
var e = res();
Assert.IsTrue(e() is Maybe <string> .None, "Not empty (" + i + ")");
}
}