monoidal-containers-0.6.4.0: Containers with monoidal accumulation
Containers with merging via monoidal accumulation. The Monoid
instances
provided by the containers
and unordered-containers
packages merge
structures in a left-biased manner instead of using the underlying monoidal
structure of the value.
This package wraps the types provided by these packages, but provides Monoid
instances implemented in terms of the value type's mappend
. For instance,
the Monoid
Map
instance looks like,
instance (Ord k, Semigroup a) => Monoid (MonoidalMap k a)