[#122] Add separate combinator (#167)

* [#122] Add separate combinator

Resolves #122

* Fix example, fix windows doctest

Author: vrom911

co-log-core/CHANGELOG.md

@@ -3,6 +3,11 @@
 `co-log-core` uses [PVP Versioning][1].
 The change log is available [on GitHub][2].
 
+## Unreleased
+
+* [#122](https://github.com/kowainik/co-log/issues/122):
+  Add the `separate` combinator.
+
 ## 0.2.0.0 — May 5, 2019
 
 * [#85](https://github.com/kowainik/co-log/issues/85):

co-log-core/co-log-core.cabal

@@ -1,6 +1,6 @@
 cabal-version:       2.4
 name:                co-log-core
-version:             0.2.0.0
+version:             0.2.1.0
 synopsis:            Composable Contravariant Comonadic Logging Library
 description:
     This package provides core types and functions to work with the @LogAction@ data type which is both simple and powerful.

co-log-core/src/Colog/Core/Action.hs

@@ -53,14 +53,15 @@ module Colog.Core.Action
        , (<<=)
        , duplicate
        , multiplicate
+       , separate
 
          -- * Higher-order combinators
        , hoistLogAction
        ) where
 
 import Control.Monad (when, (<=<), (>=>))
 import Data.Coerce (coerce)
-import Data.Foldable (fold, for_)
+import Data.Foldable (fold, for_, traverse_)
 import Data.List.NonEmpty (NonEmpty (..))
 import Data.Monoid (Monoid (..))
 import Data.Semigroup (Semigroup (..), stimesMonoid)
@@ -619,6 +620,34 @@ multiplicate (LogAction l) = LogAction $ \msgs -> l (fold msgs)
 {-# SPECIALIZE multiplicate :: Monoid msg => LogAction m msg -> LogAction m [msg] #-}
 {-# SPECIALIZE multiplicate :: Monoid msg => LogAction m msg -> LogAction m (NonEmpty msg) #-}
 
+{- | Like 'multiplicate' but instead of logging a batch of messages it logs each
+of them separately.
+
+>>> :{
+let logger :: LogAction IO Int
+    logger = logPrint
+in separate logger <& [1..5]
+:}
+1
+2
+3
+4
+5
+
+@since 0.2.1.0
+-}
+separate
+    :: forall f msg m .
+       (Traversable f, Applicative m)
+    => LogAction m msg
+    -> LogAction m (f msg)
+separate (LogAction action) = LogAction (traverse_ action)
+{-# INLINE separate #-}
+{-# SPECIALIZE separate :: Applicative m => LogAction m msg -> LogAction m [msg] #-}
+{-# SPECIALIZE separate :: Applicative m => LogAction m msg -> LogAction m (NonEmpty msg) #-}
+{-# SPECIALIZE separate :: LogAction IO msg -> LogAction IO [msg] #-}
+{-# SPECIALIZE separate :: LogAction IO msg -> LogAction IO (NonEmpty msg) #-}
+
 {- | Allows changing the internal monadic action.
 
 Let's say we have a pure logger action using 'PureLogger'

co-log-core/src/Colog/Core/IO.hs

@@ -1,3 +1,5 @@
+{-# LANGUAGE CPP #-}
+
 {- |
 Copyright:  (c) 2018-2020 Kowainik
 SPDX-License-Identifier: MPL-2.0
@@ -76,9 +78,13 @@ opening file each time we need to write to it.
 
 Opens file in 'AppendMode'.
 
+#ifndef mingw32_HOST_OS
+
 >>> logger action = action <& "foo"
 >>> withLogStringFile "/dev/stdout" logger
 foo
+
+#endif
 -}
 withLogStringFile :: MonadIO m => FilePath -> (LogAction m String -> IO r) -> IO r
 withLogStringFile path action = withFile path AppendMode $ action . logStringHandle

co-log-core/test/Doctests.hs

@@ -7,7 +7,7 @@ import Test.DocTest (doctest)
 
 main :: IO ()
 main = do
-    sourceFiles <- glob "co-log-core/src/**/*.hs"
+    sourceFiles <- glob "src/**/*.hs"
     doctest
         $ "-XInstanceSigs"
         : "-XScopedTypeVariables"