This package provides length-indexed (sized) lists, also known as vectors.
data Vec n a where VNil :: Vec 'Nat.Z a (:::) :: a -> Vec n a -> Vec ('Nat.S n) a
The functions are implemented in four flavours:
naive: with explicit recursion. It's simple, constraint-less, yet slow.
Fin n -> arepresentation, which fuses well, but makes some programs hard to write. And
data-family: which allows lazy pattern matching
inline: which exploits how GHC dictionary inlining works, unrolling recursion if the size of
Vecis known statically.
As best approach depends on the application,
vec doesn't do any magic
transformation. Benchmark your code.
This package uses fin, i.e. not
GHC.TypeLits, for indexes.
See Hasochism: the pleasure and pain of dependently typed haskell programming by Sam Lindley and Conor McBride for answers to how and why. Read APLicative Programming with Naperian Functors by Jeremy Gibbons for (not so) different ones.
Vtype, which uses
vectorpackage as backing store.
Vecis a real GADT, but tries to provide as many useful instances (upto
vector-sized Great package using
GHC.TypeLits. Current version (0.6.1.0) uses
sized-vector depends on
vecisn't light on dependencies either, but try to provide wide GHC support.
sized also depends on a
Sized f n atype is generalisation of
clash-prelude is a kitchen sink package, which has
CLaSH.Sized.Vectormodule. Also depends on
Revision history for vec
- Drop dependency on
- Add explicit
Data.Vec.DataFamily.SpineStrict.Pigeonholemodule: this let us define
Representablein a handy way.
- Reverse dependencies with
- GHC-8.4.1 support
- First version. Released on an unsuspecting world.