Predicative tries.

Please see the README on Github at https://github.com/athanclark/pred-trie#readme

pred-trie

A predicative trie library - use predicates instead of literal match to capture classes of results, instead of enumerating distinguished ones.

Usage

The predicates are existentially quantified such that a predicate creates an unknown type, while it's result must have the necessary arity, matching the quantified type, to fulfill the lookup:

PredTrie s a
  = PNil
  | forall t. PCons
      { predicate :: s -> Maybe t
      , result    :: t -> a
      }

...basically.

I broke the lookup phases into "steps", like the tries package, and used the fastest-lookup HashMapStep trie implementation for the literal lookups. For more info, read the code :D

How to run tests

stack test

Benchmarking

stack bench --benchmark-arguments="--output profile.html"