diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown new file mode 100644 --- /dev/null +++ b/CHANGELOG.markdown @@ -0,0 +1,30 @@ +# 1.1.7 +* Fixed an issue caused by changes in GHC 7.7's typechecker by using explicit `ScopedTypeVariables`. + +# 1.1.6: +* Relaxed an unnecessary strictness annotation in the fast implementation + +# 1.1.5 +* Both implementations now work on Hugs; the fast implementation ascends + from the ranks of completely unportable black magic to being merely + /mostly/ unportable black magic. + +# From 0.5 to 1.1: + +* Much faster implementation available that is about 50 /times/ faster than + 0.9 and which runs purely on black magic. This version is now used by + default. To turn it off install with the `slow` flag. If you encounter a + problem with the implementation, please contact the author. +* Removed `ReifiedNum`, `reflectNum`, and `reifyIntegral`; `reify` and + `reflect` are about 3 orders of magnitude faster than the special case + combinators were. + +# 0.5 +* Generalized the type signatures in reflect to allow you to pass any type + with kind `* -> *` wrapped around the desired type as the phantom type + argument rather than just a `Proxy`. + +# 0.4 +* Converted from `Data.Tagged` to using `Data.Proxy` for reflection. This + reduces the need for helper functions and scoped type variables in user + code. diff --git a/LICENSE b/LICENSE --- a/LICENSE +++ b/LICENSE @@ -1,4 +1,4 @@ -Copyright (c) 2009 Edward Kmett +Copyright (c) 2009-2013 Edward Kmett Copyright (c) 2004 Oleg Kiselyov and Chung-chieh Shan All rights reserved. diff --git a/README b/README deleted file mode 100644 --- a/README +++ /dev/null @@ -1,10 +0,0 @@ -reflection -========== - -This package provides an implementation of the ideas presented in the paper - - Oleg Kiselyov and Chung-Chieh Shan, "Functional Pearl: Implicit Configurations" - - -However, the API has been modified to use Rank2Types and TypeFamilies and the -implementation has been streamlined to improve performance. diff --git a/README.markdown b/README.markdown new file mode 100644 --- /dev/null +++ b/README.markdown @@ -0,0 +1,15 @@ +reflection +========== + +[![Build Status](https://secure.travis-ci.org/ekmett/reflection.png?branch=master)](http://travis-ci.org/ekmett/reflecton) + +This package provides an implementation of the ideas presented in [Functional Pearl: Implicit Configurations](http://www.cs.rutgers.edu/~ccshan/prepose/prepose.pdf) by Oleg Kiselyov and Chung-Chieh Shan. However, the API has been implemented in a much more efficient manner. + +Contact Information +------------------- + +Contributions and bug reports are welcome! + +Please feel free to contact me through github or on the #haskell IRC channel on irc.freenode.net. + +-Edward Kmett diff --git a/examples/Constraints.hs b/examples/Constraints.hs --- a/examples/Constraints.hs +++ b/examples/Constraints.hs @@ -44,9 +44,34 @@ mappend a b = Lift $ mappend_ (reflect a) (lower a) (lower b) mempty = a where a = Lift $ mempty_ (reflect a) +data ClassProxy (p :: * -> Constraint) = ClassProxy + +given :: ClassProxy c -> p s -> a -> Lift c a s +given _ _ = Lift + +eq :: ClassProxy Eq +eq = ClassProxy + +ord :: ClassProxy Ord +ord = ClassProxy + +monoid :: ClassProxy Monoid +monoid = ClassProxy + instance ReifiableConstraint Eq where data Def Eq a = Eq { eq_ :: a -> a -> Bool } reifiedIns = Sub Dict instance Reifies s (Def Eq a) => Eq (Lift Eq a s) where a == b = eq_ (reflect a) (lower a) (lower b) + +instance ReifiableConstraint Ord where + data Def Ord a = Ord { compare_ :: a -> a -> Ordering } + reifiedIns = Sub Dict + +instance Reifies s (Def Ord a) => Eq (Lift Ord a s) where + a == b = compare a b == EQ + +instance Reifies s (Def Ord a) => Ord (Lift Ord a s) where + compare a b = compare_ (reflect a) (lower a) (lower b) + diff --git a/examples/Monoid.hs b/examples/Monoid.hs --- a/examples/Monoid.hs +++ b/examples/Monoid.hs @@ -1,18 +1,20 @@ -{-# LANGUAGE Rank2Types, TypeFamilies, FlexibleContexts, UndecidableInstances #-} +{-# LANGUAGE Rank2Types, FlexibleContexts, UndecidableInstances #-} import Data.Reflection -- from reflection import Data.Monoid -- from base import Data.Proxy -- from tagged --- | Values in our dynamically constructed monoid over 'a' +-- | Values in our dynamically-constructed 'Monoid' over 'a' newtype M a s = M { runM :: a } deriving (Eq,Ord) --- | A dictionary describing the contents of a monoid +-- | A dictionary describing a 'Monoid' data Monoid_ a = Monoid_ { mappend_ :: a -> a -> a, mempty_ :: a } instance Reifies s (Monoid_ a) => Monoid (M a s) where mappend a b = M $ mappend_ (reflect a) (runM a) (runM b) mempty = a where a = M $ mempty_ (reflect a) +-- Construct a 'Monoid' instance out of a binary operation and unit that you have in scope! +-- -- > ghci> withMonoid (+) 0 $ mempty <> M 2 -- > 2 withMonoid :: (a -> a -> a) -> a -> (forall s. Reifies s (Monoid_ a) => M a s) -> a diff --git a/fast/Data/Reflection.hs b/fast/Data/Reflection.hs --- a/fast/Data/Reflection.hs +++ b/fast/Data/Reflection.hs @@ -1,11 +1,12 @@ {-# LANGUAGE CPP #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE FunctionalDependencies #-} +{-# LANGUAGE ScopedTypeVariables #-} {-# LANGUAGE Rank2Types #-} ---------------------------------------------------------------------------- -- | -- Module : Data.Reflection --- Copyright : 2009-2012 Edward Kmett, +-- Copyright : 2009-2013 Edward Kmett, -- 2012 Elliott Hird, -- 2004 Oleg Kiselyov and Chung-chieh Shan -- License : BSD3 @@ -56,5 +57,5 @@ newtype Magic a r = Magic (forall s. Reifies s a => Proxy s -> r) -- | Reify a value at the type level, to be recovered with 'reflect'. -reify :: a -> (forall s. Reifies s a => Proxy s -> r) -> r -reify a k = unsafeCoerce (Magic k) (const a) Proxy +reify :: forall a r. a -> (forall s. Reifies s a => Proxy s -> r) -> r +reify a k = unsafeCoerce (Magic k :: Magic a r) (const a) Proxy diff --git a/reflection.cabal b/reflection.cabal --- a/reflection.cabal +++ b/reflection.cabal @@ -1,5 +1,5 @@ name: reflection -version: 1.1.6 +version: 1.1.7 license: BSD3 license-file: LICENSE author: Edward A. Kmett, Elliott Hird, Oleg Kiselyov and Chung-chieh Shan @@ -9,7 +9,7 @@ bug-reports: http://github.com/ekmett/reflection/issues category: Data, Reflection, Dependent Types synopsis: Reifies arbitrary terms into types that can be reflected back into terms -copyright: 2009-2012 Edward A. Kmett, +copyright: 2009-2013 Edward A. Kmett, 2012 Elliott Hird, 2004 Oleg Kiselyov and Chung-chieh Shan build-type: Simple @@ -21,45 +21,13 @@ . The original paper can be obtained from . - . - /Changes in 1.1.6/: - . - * Relaxed an unnecessary strictness annotation in the fast implementation - . - /Changes in 1.1.5/: - . - * Both implementations now work on Hugs; the fast implementation ascends - from the ranks of completely unportable black magic to being merely - /mostly/ unportable black magic. - . - /Changes from 0.5 to 1.1/: - . - * Much faster implementation available that is about 50 /times/ faster than - 0.9 and which runs purely on black magic. This version is now used by - default. To turn it off install with the @slow@ flag. If you encounter a - problem with the implementation, please contact the author. - . - * Removed @ReifiedNum@, @reflectNum@, and @reifyIntegral@; @reify@ and - @reflect@ are about 3 orders of magnitude faster than the special case - combinators were. - . - /Changes in 0.5/: - . - * Generalized the type signatures in reflect to allow you to pass any type - with kind @* -> *@ wrapped around the desired type as the phantom type - argument rather than just a @Proxy@. - . - /Changes in 0.4/: - . - * Converted from `Data.Tagged` to using `Data.Proxy` for reflection. This - reduces the need for helper functions and scoped type variables in user - code. extra-source-files: examples/Monoid.hs examples/Constraints.hs examples/Benchmark.hs - README + CHANGELOG.markdown + README.markdown slow/Data/Reflection.hs fast/Data/Reflection.hs .travis.yml @@ -80,7 +48,7 @@ build-depends: base >= 2 && < 5, - tagged >= 0.2.3 && < 0.5 + tagged >= 0.4.4 && < 0.5 default-language: Haskell98