This document describes common abstractions that are provided by std
There are dozens of examples of how a concept of monad may be described and most of them are correct. This document has a very specific definition of the concept, as the purpose of the document is strictly practical.
There are concepts of effects and effectful computations. The purpose of effect (or sometimes it may be called context) is to enhance a certain data type with certain capabilities. For example, the List effect implies that you have a collection of elements of a certain data type. This is usually expressed as List
An idea of effectful computation makes the concept of effect a little bit wider, as it introduces an ability to perform computations within the effect. A good example of that is transformation of a list.
List<int> ints = ...
ints.Select(_ => _.ToString())
In fact, the ToString() operation is nothing more but a computation that is performed inside the List effect. In our particular case, the List effect abstracts creation of a list as result of each computation.
In general, every effect abstracts certain logic behind its computation.
There are three monadic effects that are provided by std.
- Maybe
- Try
- Future