From d17fc9aab3c90189d6f40a867efc984efc893230 Mon Sep 17 00:00:00 2001
From: Stephen Diehl <stephen.m.diehl@gmail.com>
Date: Sat, 13 Aug 2016 16:14:15 -0400
Subject: [PATCH] traceShow and traceShowId for #16

---
 docs/Index.md |  1 +
 src/Debug.hs  | 38 +++++++++++++++++++++++++++-----------
 2 files changed, 28 insertions(+), 11 deletions(-)

diff --git a/docs/Index.md b/docs/Index.md
index 4ac04b050..1b1b3dab7 100644
--- a/docs/Index.md
+++ b/docs/Index.md
@@ -29,3 +29,4 @@ Welcome to project documentation.
 - [Tuples](Tuples.md)
 - [Generics](Generics.md)
 - [Type Level Programming](TypeLevel.md)
+- [Unsafe](Unsafe.md)
diff --git a/src/Debug.hs b/src/Debug.hs
index 42be4c443..647549b11 100644
--- a/src/Debug.hs
+++ b/src/Debug.hs
@@ -6,8 +6,10 @@ module Debug (
   error,
   trace,
   traceM,
+  traceId,
   traceIO,
   traceShow,
+  traceShowId,
   traceShowM,
   notImplemented,
 ) where
@@ -16,31 +18,45 @@ import Data.Text (Text, unpack)
 import Control.Monad (Monad, return)
 
 import qualified Base as P
-import qualified Debug.Trace as T
+import Show (Print, putStrLn)
+
+import System.IO.Unsafe (unsafePerformIO)
+
+{-# WARNING trace "'trace' remains in code" #-}
+trace :: Print b => b -> a -> a
+trace string expr = unsafePerformIO (do
+    putStrLn string
+    return expr)
+
+{-# WARNING traceIO "'traceIO' remains in code" #-}
+traceIO :: Print b => b -> a -> P.IO a
+traceIO string expr = do
+    putStrLn string
+    return expr
 
 {-# WARNING error "'error' remains in code" #-}
 error :: Text -> a
 error s = P.error (unpack s)
 
-{-# WARNING trace "'trace' remains in code" #-}
-trace :: Text -> a -> a
-trace s = T.trace (unpack s)
-
 {-# WARNING traceShow "'traceShow' remains in code" #-}
 traceShow :: P.Show a => a -> b -> b
-traceShow a b = T.trace (P.show a) b
+traceShow a b = trace (P.show a) b
+
+{-# WARNING traceShowId "'traceShowId' remains in code" #-}
+traceShowId :: P.Show a => a -> a
+traceShowId a = trace (P.show a) a
 
 {-# WARNING traceShowM "'traceShowM' remains in code" #-}
 traceShowM :: (P.Show a, Monad m) => a -> m ()
-traceShowM a = T.trace (P.show a) (return ())
+traceShowM a = trace (P.show a) (return ())
 
 {-# WARNING traceM "'traceM' remains in code" #-}
 traceM :: (Monad m) => Text -> m ()
-traceM s = T.trace (unpack s) (return ())
+traceM s = trace (unpack s) (return ())
 
-{-# WARNING traceIO "'traceIO' remains in code" #-}
-traceIO :: Text -> P.IO ()
-traceIO s = T.traceIO (unpack s)
+{-# WARNING traceId "'traceM' remains in code" #-}
+traceId :: Text -> Text
+traceId s = trace s s
 
 notImplemented :: a
 notImplemented = P.error "Not implemented"