Name:           monad-wrap
Version:        0.1
Cabal-Version:  >= 1.14
build-type:     Simple
License:        BSD3
License-File:   LICENSE
Author:         David Mazieres
Stability:      experimental
Maintainer:     http://www.scs.stanford.edu/~dm/addr/
Category:       Control
Synopsis:       Wrap functions such as catch around different monads

Extra-source-files:
        multigen/multigen.hs, multigen/MultiWrap-head.hs,
	multigen/MultiLift-head.hs, Examples/wrapExample.hs,
        Examples/multiliftExample.hs, Examples/multiwrapExample.hs
Description:

        This package allows you to invoke a function on one monadic
        type passing it an argument of a different monadic type.  The
        canonical example is using a function such as @'finally'@ or
        @'bracket'@ to ensure cleanup is run regardless of any
        exceptions thrown by a computation such as @x ::  'ReaderT'
        MyConfig 'IO' b@.  If @x@ uses the 'ReaderT' function 'ask',
        it cannot be re-written to run in the 'IO' monad, and hence
        cannot be executed with a construction like @'lift' (x
        ``finally`` cleanup)@.  Instead, you must use the 'wrap'
        method, provided by module "Control.Monad.Wrap" in this
        package.

        .

        This package contains several other modules:
        "Control.Monad.WrapIO" wraps an IO action through multiple
        monad transformers.  "Control.Monad.WrapBase" generalizes the
        concept to other base monads besides IO.
        "Control.Monad.MultiWrap" implements 'mwrap', a method that
        behaves like 'wrap' but allows wrapping through multiple
        nested layers of monad transformer.  The module
        "Control.Monad.MultiLift" provides 'mlift', a version of
        'lift' that similarly lifts through multiple nested monad
        transformers.

        .

        Since this library was first released, an alternate approach
        was introduced by the @monad-control@ package.
        @monad-control@ is now the standard.  However, this package,
        @monad-wrap@, stands as an example of accomplishing similar
        goals with fewer language extensions and less complexity.  In
        particular, @monad-wrap@ does not use @RankNTypes@ or
        @TypeFamilies@, both required by @monad-control@.  Moreover,
        @monad-wrap@ is much smaller--no 'MonadWrap' method requires
        more than one line of code.  Both @monad-wrap@ and
        @monad-control@ require @UndecidableInstances@, but
        "Control.Monad.Wrap" itself does not require that extension,
        only the other modules.
    
Library
  Default-Language: Haskell2010
  Build-Depends: base < 6, transformers
  Exposed-modules:
    Control.Monad.Wrap, Control.Monad.WrapIO, Control.Monad.WrapBase,
    Control.Monad.MultiWrap, Control.Monad.MultiLift
  Other-Extensions:
    MultiParamTypeClasses, FlexibleInstances,
    FunctionalDependencies, UndecidableInstances