constraints

Constraint manipulation

Modules

Data.ConstraintConstraintKinds made type classes into types of a new kind, Constraint. Eq :: * -> Constraint
Data.Constraint.CharUtilities for working with KnownChar constraints. This module is only available on GHC 9.2 or later.
Data.Constraint.DeferrableThe idea for this trick comes from Dimitrios Vytiniotis.
Data.Constraint.ForallThis module uses a trick to provide quantification over constraints.
Data.Constraint.Lifting
Data.Constraint.NatUtilities for working with KnownNat constraints. This module is only available on GHC 8.0 or later.
Data.Constraint.SymbolUtilities for working with KnownSymbol constraints.
Data.Constraint.UnsafeUnsafe utilities used throughout constraints. As the names suggest, these

GHC 7.4 gave us the ability to talk about ConstraintKinds. They stopped crashing the compiler in GHC 7.6.

This package provides a vocabulary for working with them.

7 packages