[Haskell-cafe] ANN: signed-multiset-0.1

[Johannes Waldmann]

Stefan Holdermans <stefan <at> vectorfabrics.com> writes:

> This package provides an efficient implementation of so-called
> signed multisets, which generalise multisets by allowing for
> negative membership.

SignedMultiset a = Data.Map.Map a Integer

so what do I gain by using your library?
(what is the API difference?)

Perhaps you could state this clearly at the top
of the package description (visible on hackage).

I sometimes find I want a type "Map with default"
(the default value is stored when the Map is constructed,
and you never put keys in there that map to this default).

Best - J.W.