Control.Arrow.Writer

Documentation

module Control.Arrow.Writer.Class

newtype WriterT w r a b

Constructors

WriterT

Fields

• runWriterT :: r a (b, w)

Instances

(Monoid w, Arrow r) => ArrowWriter w (WriterT w r)

Methods

tell :: WriterT w r w ()

look :: WriterT w r a (a, w)

censor :: (w -> w) -> WriterT w r a b -> WriterT w r a b

Monoid w => ArrowTransformer (WriterT w)

Methods

lift :: Arrow r => r a b -> WriterT w r a b

tmap :: (Arrow r, Arrow s) => (forall a b. r a b -> s a b) -> WriterT w r a b -> WriterT w s a b

(Monoid w, Arrow r) => Category * (WriterT w r)

Methods

id :: cat a a

(.) :: cat b c -> cat a b -> cat a c

(Monoid w, Arrow r) => Arrow (WriterT w r)

Methods

arr :: (b -> c) -> WriterT w r b c

first :: WriterT w r b c -> WriterT w r (b, d) (c, d)

second :: WriterT w r b c -> WriterT w r (d, b) (d, c)

(***) :: WriterT w r b c -> WriterT w r b' c' -> WriterT w r (b, b') (c, c')

(&&&) :: WriterT w r b c -> WriterT w r b c' -> WriterT w r b (c, c')

(Monoid w, ArrowZero r) => ArrowZero (WriterT w r)

Methods

zeroArrow :: WriterT w r b c

(Monoid w, ArrowPlus r) => ArrowPlus (WriterT w r)

Methods

(<+>) :: WriterT w r b c -> WriterT w r b c -> WriterT w r b c

(Monoid w, ArrowChoice r) => ArrowChoice (WriterT w r)

Methods

left :: WriterT w r b c -> WriterT w r (Either b d) (Either c d)

right :: WriterT w r b c -> WriterT w r (Either d b) (Either d c)

(+++) :: WriterT w r b c -> WriterT w r b' c' -> WriterT w r (Either b b') (Either c c')

(|||) :: WriterT w r b d -> WriterT w r c d -> WriterT w r (Either b c) d

(Monoid w, ArrowApply r) => ArrowApply (WriterT w r)

Methods

app :: WriterT w r (WriterT w r b c, b) c

(Monoid w, ArrowLoop r) => ArrowLoop (WriterT w r)

Methods

loop :: WriterT w r (b, d) (c, d) -> WriterT w r b c