free-foil

Efficient Type-Safe Capture-Avoiding Substitution for Free (Scoped Monads).

Changes

CHANGELOG for free-foil

0.2.0 — 2024-10-27

  • Generate COMPLETE pragma in mkPatternSynonyms (see #26)
  • Polykind ZipMatchK class with default generic implementation via kind-generics (see #27)
  • New experimental TH generation for Free Foil with support for rich syntax in Control.Monad.Free.Foil.TH.MkFreeFoil (see #28)

0.1.0 — 2024-08-18

  • Generalize functions for binders, support general patterns (see #16)

    • Add withPattern method to CoSinkable. It can be seen as a CPS-style traversal over binders in a pattern. Our Template Haskell support covers generation of withPattern, so normally the user does not have to think about it.

    • Generalize many functions to work with arbitrary patterns, not just NameBinder:

      • withFreshPattern — to
      • withRefreshedPattern and withRefreshedPattern'
      • extendScopePattern — extend a given scope with all binders in a given pattern
      • namesOfPattern — collect all names from a pattern
      • unsinkNamePattern — try to unsink names from a scope extended with binders from a given pattern
      • assertDistinctPattern — establish that extended scope is distinct (if outer scope is)
      • assertDistinctExt — establish that extended scope is distinct and indeed an extension
    • Implement unification for patterns in unifyPatterns. This turns out to be one of the most difficult places, especially for compound patterns. Implementing patterns properly on the user side not comfortable at all! Luckily, we provide useful helpers like andThenUnifyPatterns and andThenUnifyNameBinders, as well as Template Haskell support to derive UnifiablePattern.

    • Generalize Free Foil to support arbitrary patterns.

    • The Foil and FreeFoilTH implementations now make use of the generalized pattern support.

0.0.3 — 2024-06-20

  • Add α-equivalence checks and α-normalization (see #12):

    • Control.Monad.Foil now offers more helpers to work with binder renaming and binder unification. These helpers can be used to implement (efficient) α-equivalence.
    • In Control.Monad.Free.Foil general implementation of α-equivalence and α-normalization is provided.
  • Add general conversion functions for free foil (see #14):

    • Control.Monad.Free.Foil now offers convertToAST and convertFromAST functions enabling easier implementation of conversions raw and scope-safe representations.
  • Add Template Haskell functions for free foil (see #14):

    • Control.Monad.Free.Foil.TH contains many useful functions to generate free foil from a raw representation (e.g. generated via BNFC), including generation of the signature, convenient pattern synonyms, ZipMatch instance, and conversion helpers.

0.0.2 — 2024-06-18

  • Improve TH to support parametrized data types (see #11)
  • Split lambda-pi into its own package (see #10)
  • Switch to template-haskell >= 2.21.0.0 (to support latest Stackage Nightly)
  • Fix doctests (see #9)

0.0.1 — 2024-06-08

First release, corresponding to the ICCQ 2024 paper.