X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;ds=sidebyside;f=Debug%2FTrace.hs;h=40915215c97534fdbc5e3ed67009b8dcb031fe6e;hb=b50e64c6f56695ce4c5b874e36c26db1c62be46e;hp=3e369f5e183c12f728ba0b1534276f33a0325310;hpb=66bcbe67b61d83cb01b6d2c876e7b06e034fba88;p=ghc-base.git

diff --git a/Debug/Trace.hs b/Debug/Trace.hs
index 3e369f5..4091521 100644
--- a/Debug/Trace.hs
+++ b/Debug/Trace.hs
@@ -28,7 +28,7 @@ import System.IO (hPutStrLn,stderr)
 #endif
 
 -- | 'putTraceMsg' function outputs the trace message from IO monad.
--- Usually the output stream is 'stderr' but if the function is called
+-- Usually the output stream is 'System.IO.stderr' but if the function is called
 -- from Windows GUI application then the output will be directed to the Windows
 -- debug console.
 putTraceMsg :: String -> IO ()
@@ -56,3 +56,11 @@ trace :: String -> a -> a
 trace string expr = unsafePerformIO $ do
     putTraceMsg string
     return expr
+
+{-|
+Like 'trace', but uses 'show' on the argument to convert it to a 'String'.
+
+> traceShow = trace . show
+-}
+traceShow :: (Show a) => a -> b -> b
+traceShow = trace . show