Module Base.Monad

A monad is an abstraction of the concept of sequencing of computations. A value of type 'a monad represents a computation that returns a value of type 'a.

module type Basic = sig ... end
module type Basic2 = sig ... end

Multi parameter monad. The second parameter gets unified across all the computation. This is used to encode monads working on a multi parameter data structure like (('a,'b) result).

module type Basic3 = sig ... end

Multi parameter monad. The second and third parameters get unified across all the computation.

module type Basic_indexed = sig ... end

Indexed monad, in the style of Atkey. The second and third parameters are composed across all computation. To see this more clearly, you can look at the type of bind:

module type Basic_local = sig ... end
module type Basic2_local = sig ... end

Multi parameter monad. The second parameter gets unified across all the computation. This is used to encode monads working on a multi parameter data structure like (('a,'b) result).

module type Infix = sig ... end
module type Infix2 = sig ... end

Same as Infix, except the monad type has two arguments. The second is always just passed through.

module type Infix3 = sig ... end

Same as Infix, except the monad type has three arguments. The second and third are always just passed through.

module type Infix_indexed = sig ... end

Same as Infix, except the monad type has three arguments. The second and third are composed across all computation.

module type Infix_local = sig ... end
module type Infix2_local = sig ... end

Same as Infix, except the monad type has two arguments. The second is always just passed through.

module type Syntax = sig ... end

Opening a module of this type allows one to use the %bind and %map syntax extensions defined by ppx_let, and brings return into scope.

module type Syntax2 = sig ... end
module type Syntax3 = sig ... end
module type Syntax_indexed = sig ... end
module type Syntax_local = sig ... end

Opening a module of this type allows one to use the %bind and %map syntax extensions defined by ppx_let, and brings return into scope.

module type Syntax2_local = sig ... end
module type S_without_syntax = sig ... end
module type S_without_syntax_local = sig ... end
module type S = sig ... end
module type S2 = sig ... end

The same as S except the monad type has two arguments. The second is always just passed through.

module type S3 = sig ... end

The same as S except the monad type has three arguments. The second and third are always just passed through.

module type S_indexed = sig ... end

The same as S except the monad type has three arguments. The second and third are composed across all computation.

module type S_local = sig ... end
module type S2_local = sig ... end

The same as S except the monad type has two arguments. The second is always just passed through.

module Make (X : Basic) : S with type 'a t := 'a X.t
module Make2 (X : Basic2) : S2 with type ('a, 'e) t := ('a, 'e) X.t

The same as S except the monad type has two arguments. The second is always just passed through.

module Make3 (X : Basic3) : S3 with type ('a, 'd, 'e) t := ('a, 'd, 'e) X.t

The same as S except the monad type has three arguments. The second and third are always just passed through.

module Make_indexed (X : Basic_indexed) : S_indexed with type ('a, 'd, 'e) t := ('a, 'd, 'e) X.t

The same as S except the monad type has three arguments. The second and third are composed across all computation.

module Make_local (X : Basic_local) : S_local with type 'a t := 'a X.t
module Make2_local (X : Basic2_local) : S2_local with type ('a, 'e) t := ('a, 'e) X.t

The same as S except the monad type has two arguments. The second is always just passed through.

module Of_monad (Monad : S) (M : sig ... end) : S with type 'a t := 'a M.t

Define a monad through an isomorphism with an existing monad. For example:

module Of_monad2 (Monad : S2) (M : sig ... end) : S2 with type ('a, 'b) t := ('a, 'b) M.t

The same as S except the monad type has two arguments. The second is always just passed through.

module Of_monad3 (Monad : S3) (M : sig ... end) : S3 with type ('a, 'b, 'c) t := ('a, 'b, 'c) M.t

The same as S except the monad type has three arguments. The second and third are always just passed through.

module Of_monad_indexed (Monad : S_indexed) (M : sig ... end) : S_indexed with type ('a, 'i, 'j) t := ('a, 'i, 'j) M.t

The same as S except the monad type has three arguments. The second and third are composed across all computation.

module Ident : S_local with type 'a t = 'a

An eager identity monad with functions heavily annotated with @inlined or @inline hint.