std.identity

The identity functor and monad.

Types

type Identity a = a

Values

#[implicit]
let functor : Functor Identity

A Functor represents an action on a parameterized type which does not change the structure with the mapped type.

The following laws should hold:

  • map id == id
  • map (f << g) == map f << map g

A Functor with application.

The following laws should hold:

  • wrap id <*> v = v
  • wrap (<<) <*> u <*> v <*> w = u <*> (v <*> w)
  • wrap f <*> wrap x = wrap (f x)
  • u <*> wrap y = wrap (\g -> g x) <*> u

#[implicit]
let monad : Monad Identity

A generalised interface for imperatively sequencing actions