preface

An opinionated library for function programming (à La Haskell)
IN THIS PACKAGE
type 'a f

The parametric type (which, unlike a Preface_specs.Free_selective don't need to be a Preface_specs.Functor).

type _ t =
| Pure : 'a -> 'a t
| Select : (( 'b -> 'a, 'a ) Either.t t * 'b f) -> 'a t

The type held by the Freer selective.

val promote : 'a f -> 'a t

Promote a value from the Preface_specs.Functor into the Freer selective.

module To_selective (Selective : Selective.API) : TO_SELECTIVE with type 'a t := 'a t and type 'a f := 'a f and type 'a selective := 'a Selective.t

The natural transformation from a Freer selective to an other Preface_specs.Selective.

module To_monoid (Monoid : Monoid.CORE) : TO_MONOID with type 'a t := 'a t and type 'a f := 'a f and type monoid := Monoid.t

The natural transformation from a Freer selective to a Preface_specs.Monoid.

Selective API

A Freer selective is also a Preface_specs.Selective.

Type

Functions

val select : ( 'a, 'b ) Preface_core.Shims.Either.t t -> ( 'a -> 'b ) t -> 'b t

select e f apply f if e is Left. It allow to skip effect using Right.

val branch : ( 'a, 'b ) Preface_core.Shims.Either.t t -> ( 'a -> 'c ) t -> ( 'b -> 'c ) t -> 'c t

branch is like select. It chooses between two effects.

include Applicative.WITH_PURE with type 'a t := 'a t
include Apply.WITH_APPLY with type 'a t := 'a t
val apply : ( 'a -> 'b ) t -> 'a t -> 'b t

Applicative functor of ('a -> 'b) t over 'a t to 'b t.

include Applicative.WITH_PURE with type 'a t := 'a t
include Apply.WITH_MAP_AND_PRODUCT with type 'a t := 'a t
include Functor.WITH_MAP with type 'a t := 'a t
val map : ( 'a -> 'b ) -> 'a t -> 'b t

Mapping over from 'a to 'b over 'a t to 'b t.

include Apply.WITH_PRODUCT with type 'a t := 'a t
val product : 'a t -> 'b t -> ('a * 'b) t

Product functor mapping from 'a t and 'b t to ('a * 'b) t.

include Applicative.WITH_PURE with type 'a t := 'a t
val pure : 'a -> 'a t

Lift a value from 'a into a new 'a t.

include Apply.WITH_LIFT2 with type 'a t := 'a t
val lift2 : ( 'a -> 'b -> 'c ) -> 'a t -> 'b t -> 'c t

Mapping over from 'a and 'b to 'c over 'a t and 'b t to 'c t.

include Apply.OPERATION with type 'a t := 'a t
val lift : ( 'a -> 'b ) -> 'a t -> 'b t

Mapping over from 'a to 'b over 'a t to 'b t.

val lift3 : ( 'a -> 'b -> 'c -> 'd ) -> 'a t -> 'b t -> 'c t -> 'd t

Mapping over from 'a and 'b and 'c to 'd over 'a t and 'b t and 'c t to 'd t.

val replace : 'a -> 'b t -> 'a t

Create a new 'a t, replacing all values in the 'b t by given a value of 'a.

val void : 'a t -> unit t

Create a new unit t, replacing all values in the 'a t by unit.

val if_ : bool t -> 'a t -> 'a t -> 'a t

Same of branch but using a Boolean as disjunction.

val bind_bool : bool t -> ( bool -> 'a t ) -> 'a t

Monad bind specialized for Boolean.

val when_ : bool t -> unit t -> unit t

Conditionally perform an effect.

val exists : ( 'a -> bool t ) -> 'a list -> bool t

Selective version of List.exists.

val for_all : ( 'a -> bool t ) -> 'a list -> bool t

Selective version of List.for_all.

val or_ : bool t -> bool t -> bool t

Or combinator.

val and_ : bool t -> bool t -> bool t

And combinator.

val while_ : bool t -> unit t

Keep checking an effectful condition while it holds.

Infix operators

module Infix : Selective.INFIX with type 'a t = 'a t
include Apply.INFIX with type 'a t := 'a t
val (<*>) : ( 'a -> 'b ) t -> 'a t -> 'b t

Applicative functor of ('a -> 'b) t over 'a t to 'b t.

val (<**>) : 'a t -> ( 'a -> 'b ) t -> 'b t

Flipped Applicative functor of ('a -> 'b) t over 'a t to 'b t.

val (*>) : unit t -> 'a t -> 'a t

Discard the value of the first argument.

val (<*) : 'a t -> unit t -> 'a t

Discard the value of the second argument.

val (<$>) : ( 'a -> 'b ) -> 'a t -> 'b t
val (<&>) : 'a t -> ( 'a -> 'b ) -> 'b t

Flipped and infix version of Preface_specs.Functor.CORE.map.

val (<$) : 'a -> 'b t -> 'a t
val ($>) : 'a t -> 'b -> 'b t

Flipped and infix version of Preface_specs.Functor.OPERATION.replace.

val (<$>) : ( 'a -> 'b ) -> 'a t -> 'b t
val (<&>) : 'a t -> ( 'a -> 'b ) -> 'b t

Flipped and infix version of Preface_specs.Functor.CORE.map.

val (<$) : 'a -> 'b t -> 'a t
val ($>) : 'a t -> 'b -> 'b t

Flipped and infix version of Preface_specs.Functor.OPERATION.replace.

val (<*?) : ( 'a, 'b ) Preface_core.Shims.Either.t t -> ( 'a -> 'b ) t -> 'b t

Infix version of CORE.select.

val (<||>) : bool t -> bool t -> bool t

Infix version of CORE.or_.

val (<&&>) : bool t -> bool t -> bool t

Infix version of CORE.and_.

Syntax

module Syntax : Selective.SYNTAX with type 'a t = 'a t
include Apply.SYNTAX with type 'a t := 'a t
val let+ : 'a t -> ( 'a -> 'b ) -> 'b t

Flipped mapping over from 'a to 'b over 'a t to 'b t.

val and+ : 'a t -> 'b t -> ('a * 'b) t

Product functor mapping from 'a t and 'b t to ('a * 'b) t.