[commit: ghc] master: base: Remove deprecated Chan combinators (361af62)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/361af6280d7025ac3e24d79c209b465db6f231f8/ghc

>---------------------------------------------------------------

commit 361af6280d7025ac3e24d79c209b465db6f231f8
Author: Ben Gamari <bgamari.foss at gmail.com>
Date:   Tue Oct 3 15:09:12 2017 -0400

    base: Remove deprecated Chan combinators
    
    Removes isEmptyChan and unGetChan, which have been deprecated for a very
    long time. See #13561.
    
    Test Plan: Validate
    
    Reviewers: austin, hvr
    
    Subscribers: rwbarton, thomie
    
    GHC Trac Issues: #13561
    
    Differential Revision: https://phabricator.haskell.org/D4060


>---------------------------------------------------------------

361af6280d7025ac3e24d79c209b465db6f231f8
 libraries/base/Control/Concurrent/Chan.hs | 21 ---------------------
 libraries/base/changelog.md               |  3 +++
 2 files changed, 3 insertions(+), 21 deletions(-)

diff --git a/libraries/base/Control/Concurrent/Chan.hs b/libraries/base/Control/Concurrent/Chan.hs
index ebbec7e..9bfd40b 100644
--- a/libraries/base/Control/Concurrent/Chan.hs
+++ b/libraries/base/Control/Concurrent/Chan.hs
@@ -1,6 +1,5 @@
 {-# LANGUAGE Trustworthy #-}
 {-# LANGUAGE CPP #-}
-{-# LANGUAGE StandaloneDeriving #-}
 
 -----------------------------------------------------------------------------
 -- |
@@ -31,8 +30,6 @@ module Control.Concurrent.Chan
         writeChan,
         readChan,
         dupChan,
-        unGetChan,
-        isEmptyChan,
 
           -- * Stream interface
         getChanContents,
@@ -137,24 +134,6 @@ dupChan (Chan _ writeVar) = do
    newReadVar <- newMVar hole
    return (Chan newReadVar writeVar)
 
--- |Put a data item back onto a channel, where it will be the next item read.
-unGetChan :: Chan a -> a -> IO ()
-unGetChan (Chan readVar _) val = do
-   new_read_end <- newEmptyMVar
-   modifyMVar_ readVar $ \read_end -> do
-     putMVar new_read_end (ChItem val read_end)
-     return new_read_end
-{-# DEPRECATED unGetChan "if you need this operation, use Control.Concurrent.STM.TChan instead.  See <http://ghc.haskell.org/trac/ghc/ticket/4154> for details" #-} -- deprecated in 7.0
-
--- |Returns 'True' if the supplied 'Chan' is empty.
-isEmptyChan :: Chan a -> IO Bool
-isEmptyChan (Chan readVar writeVar) = do
-   withMVar readVar $ \r -> do
-     w <- readMVar writeVar
-     let eq = r == w
-     eq `seq` return eq
-{-# DEPRECATED isEmptyChan "if you need this operation, use Control.Concurrent.STM.TChan instead.  See <http://ghc.haskell.org/trac/ghc/ticket/4154> for details" #-} -- deprecated in 7.0
-
 -- Operators for interfacing with functional streams.
 
 -- |Return a lazy list representing the contents of the supplied
diff --git a/libraries/base/changelog.md b/libraries/base/changelog.md
index 7778ceb..2f42e22 100644
--- a/libraries/base/changelog.md
+++ b/libraries/base/changelog.md
@@ -56,6 +56,9 @@
   * Add `installSEHHandlers` to `MiscFlags` in `GHC.RTS.Flags` to determine if
     exception handling is enabled.
     
+  * The deprecated functions `isEmptyChan` and `unGetChan` in
+    `Control.Concurrent.Chan` have been removed (#13561).
+
   * Add `generateCrashDumpFile` to `MiscFlags` in `GHC.RTS.Flags` to determine
     if a core dump will be generated on crashes.