const package:Cabal-syntax

const x y always evaluates to x, ignoring its second argument.

>>> const 42 "hello"
42

>>> map (const 42) [0..3]
[42,42,42,42]

The Const functor.

Allow a class method's type to place additional constraints on a class type variable.

Allow type classimplicit parameterequality constraints to be used as types with the special kind constraint. Also generalise the (ctxt => ty) syntax so that any type of kind constraint can occur before the arrow.

A version constraint on a package. Different from ExeDependency and Dependency since it does not specify the need for a component, not even the main library. There are a few places in the codebase where Dependency was used where PackageVersionConstraint is not used instead (#5570).

Allow forall in constraints.