Module

# Control.Category

- Package
- purescript-prelude
- Repository
- purescript/purescript-prelude

### #Category Source

`class (Semigroupoid a) <= Category a where`

`Category`

s consist of objects and composable morphisms between them, and
as such are `Semigroupoids`

, but unlike `semigroupoids`

must have an identity element.

Instances must satisfy the following law in addition to the
`Semigroupoid`

law:

- Identity:
`id <<< p = p <<< id = p`

#### Members

`id :: forall t. a t t`

#### Instances

## Re-exports from **Control.**Semigroupoid

### #Semigroupoid Source

`class Semigroupoid a where`

A `Semigroupoid`

is similar to a `Category`

but does not
require an identity element `id`

, just composable morphisms.

`Semigroupoid`

s must satisfy the following law:

- Associativity:
`p <<< (q <<< r) = (p <<< q) <<< r`

One example of a `Semigroupoid`

is the function type constructor `(->)`

,
with `(<<<)`

defined as function composition.

#### Members

`compose :: forall b c d. a c d -> a b c -> a b d`

#### Instances

- Modules
- Control.
Applicative - Control.
Apply - Control.
Bind - Control.
Category - Control.
Monad - Control.
Semigroupoid - Data.
Boolean - Data.
BooleanAlgebra - Data.
Bounded - Data.
CommutativeRing - Data.
DivisionRing - Data.
Eq - Data.
EuclideanRing - Data.
Field - Data.
Function - Data.
Functor - Data.
HeytingAlgebra - Data.
NaturalTransformation - Data.
Ord - Data.
Ord. Unsafe - Data.
Ordering - Data.
Ring - Data.
Semigroup - Data.
Semiring - Data.
Show - Data.
Unit - Data.
Void - Prelude