Data/Map/Lazy/Merge.hs

    {-# LANGUAGE CPP #-}
    #if !defined(TESTING) && __GLASGOW_HASKELL__ >= 703
    {-# LANGUAGE Safe #-}
    #endif

    #include "containers.h"

    {-# OPTIONS_HADDOCK hide #-}

    -----------------------------------------------------------------------------
    -- |
    -- Module      :  Data.Map.Lazy.Merge
    -- Copyright   :  (c) David Feuer 2016
    -- License     :  BSD-style
    -- Maintainer  :  libraries@haskell.org
    -- Portability :  portable
    --
    -- This module defines an API for writing functions that merge two
    -- maps. The key functions are 'merge' and 'mergeA'.
    -- Each of these can be used with several different "merge tactics".
    --
    -- The 'merge' and 'mergeA' functions are shared by
    -- the lazy and strict modules. Only the choice of merge tactics
    -- determines strictness. If you use 'Data.Map.Strict.Merge.mapMissing'
    -- from "Data.Map.Strict.Merge" then the results will be forced before
    -- they are inserted. If you use 'Data.Map.Lazy.Merge.mapMissing' from
    -- this module then they will not.
    --
    -- == Efficiency note
    --
    -- The 'Category', 'Applicative', and 'Monad' instances for 'WhenMissing'
    -- tactics are included because they are valid. However, they are
    -- inefficient in many cases and should usually be avoided. The instances
    -- for 'WhenMatched' tactics should not pose any major efficiency problems.

    module Data.Map.Lazy.Merge {-# DEPRECATED "Use \"Data.Map.Merge.Lazy\"." #-}
        ( module Data.Map.Merge.Lazy ) where

    import Data.Map.Merge.Lazy