LiftedValues
Lazy functional value wrappers for C#
This package exists to allow transparency between values and zero-argument functions, which enables some convenient functional programming techniques.
By way of explanation, here's a simple example: let's say you have a pair of dice, a fixed value which modifies the die roll, and another modifier that requires an external lookup. With LiftedValues they can all be kept in the same list of Value<int>, turning this into a simple foreach enumeration where none of the required computations (die rolls, lookup) are performed until they're actually needed!
In addition to Value<T>, LiftedValues provides Maybe<T> which is roughly the nullable equivalent: it evaluates to either a good Value<T>, or to Nothing, which can be distinguished using C#'s type-level is operator, yielding very nice code:
var maybeValue = someMaybe.Eval();
if (maybeValue is Nothing) {
HandleNothing();
} else {
HandleValue(maybeValue.Eval());
}
Wrapping simple values and functions is covered via factory methods on the static Value and Maybe classes. There are also Maybe wrappers for WeakReference, including weak delegates to instance methods. (Compatible with Unity3D!)
To streamline more complex use, Value<T> and Maybe<T> are actually interfaces, allowing them to be inherited along with another class. Yes, this violates conventional naming. Too bad. ;)
Despite names borrowed from Haskell, the FP-wary can rest easy: there are no monads here.