cats.mtl
FunctorTell[F, L] is the ability to "log" values L inside a context F[_], as an effect.
FunctorTell[F, L]
L
F[_]
FunctorTell has no external laws.
FunctorTell
FunctorTell has one internal law:
def writerIsTellAndMap(a: A, l: L) = { (tell(l) as a) <-> writer(a, l) } def tupleIsWriterFlipped(a: A, l: L) = { writer(a, l) <-> tuple((l, a)) }
FunctorTell[F, L]
is the ability to "log" valuesL
inside a contextF[_]
, as an effect.FunctorTell
has no external laws.FunctorTell
has one internal law: