Effects.Writer

Writer effect.

Documentation

data Writer w a where

Writer effect for writing to a strean w

Constructors

Tell

Write to a stream w

Fields

• :: w

  value to write

• -> Writer w ()

tell :: Member (Writer w) es => w -> Prog es ()

Wrapper for Tell

tellM :: Member (Writer w) es => w -> Model env es ()

Wrapper for Tell inside Model

handleWriter

Arguments

:: forall w es a. Monoid w

=> Prog (Writer w ': es) a

-> Prog es (a, w)

(output, final stream)

Handle the Writer effect for a stream w

handleWriterM

Arguments

:: Monoid w

=> Model env (Writer w ': es) a

-> Model env es (a, w)

(output, final stream)

Handle the Writer effect inside a Model