name: cluss
category: type system, constraints
version: 0.2
x-revision: 1
license: BSD3
license-file: LICENSE
cabal-version: >= 1.10
tested-with: GHC==7.8.3
author: Yusuke Matsushita
maintainer: Yusuke Matsushita <y.skm24t@gmail.com>
stability: provisional
homepage: https://github.com/Kinokkory/cluss
bug-reports: https://github.com/Kinokkory/cluss/issues
copyright: (c) Yusuke Matsushita 2014
synopsis: simple alternative to type classes
description:
    A *cluss* enables you to achieve function overloading, or ad-hoc polymorphism,
    without creating a new type class.
    .
    In order to give ad-hoc polymorphism to a type variable @a@,
    you simply use @'In'@ with a list of \"type patterns\" like @In [Type T, ...] a@,
    which indicates that the type matches some of the patterns;
    which is analogous to a type class indicating that a type matches some of its \"instances\".
    The constraint @In [Type T, ...] a@ is what we call a \"cluss\".
    .
    Clusses can easily be used in a nested way
    and even be __recursive__;
    therefore, they are /expressive/ enough to imitate Haskell-98-style type classes.
    .
    Clusses, /however/, go beyond a mere alternative to type classes.
    They have __closed__ and __prioritized__ instances and __open__ methods,
    while type classes have open and unprioritized instances and closed methods.
    Those properties give clusses the advantages different from type classes:
    .
        * You can /judge/ whether a type @a@ belongs to a cluss @'In' as@,
        on some level, writing @Has as a@,
        since cluss instances are closed.
    .
        * You can make cluss instances more /flexibly/,
        without causing overlapping instances or incoherent instances,
        since cluss instances are prioritized.
    .
        * You can /create/ new methods for clusses anywhere in any module,
        since cluss methods are open.
    .
    More information can be found in the <http://hackage.haskell.org/package/cluss hackage's haddock> or the <http://kinokkory.github.io/cluss/ updated haddock>.

build-type: Simple

source-repository head
    type: git
    location: git@github.com:Kinokkory/cluss.git

library
    hs-source-dirs: src
    default-language: Haskell2010
    other-extensions:
        Trustworthy,
        ScopedTypeVariables, TypeOperators,
        RankNTypes, TypeFamilies,
        DataKinds, ConstraintKinds, PolyKinds,
        MultiParamTypeClasses, FlexibleInstances, UndecidableInstances, FlexibleContexts
    build-depends:
        base ==4.*,
        template-haskell >=2.5
    exposed-modules: Type.Cluss, Type.Cluss.TH
    ghc-options: -Wall