name: type-level-sets
version: 0.5
synopsis: Type-level sets (with value-level counterparts and various operations)
description:
This package provides type-level sets (no duplicates, sorted to provide a nomral form) via 'Set',
with value-level counterparts. Described in the paper \"Embedding effect systems in Haskell\" by Dominic Orchard
and Tomas Petricek (Haskell Symposium, 2014)
.
Here is a brief example:
.
>
> import Data.Type.Set
>
> foo :: Set '["x" :-> Int, "z" :-> Int, "w" :-> Int]
> foo = Ext ((Var :: (Var "x")) :-> 2) $
> Ext ((Var :: (Var "z")) :-> 4) $
> Ext ((Var :: (Var "w")) :-> 5) $
> Empty
>
> bar :: Set '["y" :-> Int, "w" :-> Int]
> bar = Ext ((Var :: (Var "y")) :-> 3) $
> Ext ((Var :: (Var "w")) :-> 1) $
> Empty
>
> -- foobar :: Set '["w" :-> Int, "x" :-> Int, "y" :-> Int, "z" :-> Int]
> foobar = foo `union` bar
.
The 'Set' type for 'foobar' here shows the normalised form (sorted with no duplicates).
The type signatures is commented out as it can be infered. Running the example we get:
.
> >>> foobar
> [(Var :-> 1), (Var :-> 2), (Var :-> 3), (Var :-> 4)]
.
Thus, we see that the first value paired with the \"w\" variable is dropped.
.
license: BSD3
license-file: LICENSE
category: Type System, Data Structures
copyright: 2013-14 University of Cambridge
author: Dominic Orchard
maintainer: Dominic Orchard
stability: experimental
build-type: Simple
cabal-version: >= 1.6
tested-with: GHC == 7.8.2
extra-source-files: example.hs
source-repository head
type: git
location: https://github.com/dorchard/type-level-sets
library
hs-source-dirs: src
exposed-modules: Data.Type.Set
build-depends: base < 5,
ghc-prim