Mappings

What's it do?

This package does two jobs:

• It offers a general typeclass Mapping for types which represent functions k -> v (for fixed k, but arbitrary ordered v).

  There are some fairly straightforward examples which build up mappings where k is Either, or a pair, or Maybe, or Bool.

• Three less trivial implementations are provided:

  • Decision diagrams, with nodes which may themselves be an arbitrary Mapping (there is some code for viewing these in the examples directory);

  • Piecewise constant maps on an ordered domain k;

  • Maps equipped with a default value.

Why did I bother?

The aim is to use decision diagrams with nodes that are piecewise constant maps to store monomials for Grobner basis algorithms.