vec
Version 0.3 revision 2 uploaded by phadej.
Package meta
- Synopsis
- Vec: length-indexed (sized) list
- Description
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.
pull: using
Fin n -> a
representation, which fuses well, but makes some programs hard to write. Anddata-family: which allows lazy pattern matching
inline: which exploits how GHC dictionary inlining works, unrolling recursion if the size of Vec is 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.For
lens
oroptics
support see vec-lens and vec-optics packages respectively.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.
Similar packages
linear has V type, which uses Vector from
vector
package as backing store.Vec
is a real GADT, but tries to provide as many useful instances (uptolens
).vector-sized Great package using
GHC.TypeLits
. Current version (0.6.1.0) usesfinite-typelits
andInt
indexes.sized-vector depends on
singletons
package.vec
isn't light on dependencies either, but try to provide wide GHC support.sized also depends on a
singletons
package. TheSized f n a
type is generalisation oflinear
'sV
for anyListLike
.clash-prelude is a kitchen sink package, which has
CLaSH.Sized.Vector
module. Also depends onsingletons
.
- Author
- Oleg Grenrus <oleg.grenrus@iki.fi>
- Bug reports
- https://github.com/phadej/vec/issues
- Category
- Data, Dependent Types
- Copyright
- (c) 2017-2019 Oleg Grenrus
- Homepage
- https://github.com/phadej/vec
- Maintainer
- Oleg.Grenrus <oleg.grenrus@iki.fi>
- Package URL
- n/a
- Stability
- n/a