Tungsten

tungsten is a (highly experimental) library bringing deforestation to any recursive structure for free.

The only prerequisite is to define the concerned structure as a fixed-point using the provided Fix operator from the Tungsten.Fix module. It also defines a generalization of the foldr/build rewrite rule, targeting catamorphisms on any fixed-point structures.

Haddock-generated documentation is available at https://nobrakal.github.io/tungsten/

Examples

Some examples of use can be seen in:

• Tungsten.Structure.List
• Tungsten.Structure.Tree
• Tungsten.Structure.Graph

Is this valid?

See a more-or-less formal proof in doc/validity.md.

Is this working?

Even if valid from a theoritical point of view, does it work?

Some tests can be found in the test/ directory. They use the great inspection-testing package to test rewrite-rules firing.

Is does not work for me!

Be sure to compile with rewrite rules enabled and the -fspec-constr flag.

The name

Tungsten is the metal with the highest fusion (or melting) point.