Mnd 1.1.0

A small library for programming with monads. It aims to be comprehensible instead of comprehensive Everything is standard and already exists in various places, this is simply a selection for easy re-use:

• An interface to define monads with one or two type parameters
• A small selection of monadic functions such as (>>=) or mapM
• Support for let* and let+ syntax
• A few standard instances of monads

The details can be found in the documentation. Feedback is welcome on the GitHub repository.

Functions

The individual functions are documented in the MONAD interface.

• (>>=)
• (>>)
• (|>>)
• foldM
• fold1M
• mapM
• forM
• iterM
• ifM

Syntax

OCaml 4.08.0 added support for user-defined binding operators to facilitate working with monads and similar structures. Monads defined with this library automatically have access to the let* and let+ syntax.

Instances

• Option: Canonical instance of 'a option. Also known as Maybe.
• Result: Canonical instance of ('a,'b) result. Also known as Error or Either. Provides and* and and+ with the semantics that if either compuation fails, the combined product computation also fails. If both arguments of a product fail then the result is the error of the first one.
• Reader: Also known as Env, Environment or configuration monad.
• Writer: Also known as logger monad.
• State