class Injects r_ (m :: Type -> Type) (accum :: Type) | accum -> m where Source #
Mirror image of Has
.
Can be useful with AccumConstructor
to register particular
monoidal values into a "wider" monoidal value which is accumulated accross
all components.
Methods
inject :: r_ m -> accum Source #
Given a value parameterized by the accumulator's effect monad m
,
produce an accumulator.