Bebop.Monads 1.0.0

Construction

Maybe<string> m = Maybe.From("these pretzels are making me thirsty");
Maybe<int> n = Maybe.Nothing<int>(); 

Binding

The method Map provides the monadic binding mechanism.

This example maps from an integer value to a string value:

Maybe<int> m = Maybe.From(123);
Maybe<string> n = m.Map(x => Maybe.From("something completely different")); // n represents the string

This example does not execute the binder (the lambda) because the source Maybe is empty. An empty target Maybe is created instead:

Maybe<int> m = Maybe.Nothing<int>();
Maybe<string> n = m.Map(x => Maybe.From("something completely different")); // n is Nothing

Alternative Values

The Maybe allows for 'materialising' to a value of type T by providing an alternative value that is chosen if the Maybe does not have an internal value:

Maybe<int> m = Maybe.From(123);
int r = m.OrElse(456); // 123

Maybe<int> n = Maybe.Nothing<int>();
int s = n.OrElse(456); // 456

It is also possible to use lazy construction of the alternative value if creationg of this value is costly:

Maybe<int> m = Maybe.From(123);
int r = m.OrElse(() => 456); // 123

Maybe<int> n = Maybe.Nothing<int>();
int s = n.OrElse(() => 456); // 456