A semigroup in type F must satisfy two laws:
A semigroup in type F must satisfy two laws:
∀ a, b in F, append(a, b)
is also in F
. This is enforced by the type system.∀ a, b, c
in F
, the equation append(append(a, b), c) = append(a, append(b , c))
holds.
The binary operation to combine f1
and f2
.
The binary operation to combine f1
and f2
.
Implementations should not evaluate the by-name parameter f2
if result
can be determined by f1
.
An scalaz.Apply, that implements ap
with append
.
An scalaz.Apply, that implements ap
with append
. Note
that the type parameter α
in Apply[λ[α => F]]
is
discarded; it is a phantom type. As such, the functor cannot
support scalaz.Bind.
Every Semigroup
gives rise to a scalaz.Compose, for which
the type parameters are phantoms.
Every Semigroup
gives rise to a scalaz.Compose, for which
the type parameters are phantoms.
compose.semigroup
= this
For n = 0
, value
For n = 1
, append(value, value)
For n = 2
, append(append(value, value), value)