1 files changed, 34 insertions, 0 deletions
diff --git a/pkgs/development/tools/haskell/ihaskell/use-classy-prelude.patch b/pkgs/development/tools/haskell/ihaskell/use-classy-prelude.patch
new file mode 100644
index 00000000000..b2c1362b62f
--- /dev/null
+++ b/pkgs/development/tools/haskell/ihaskell/use-classy-prelude.patch
@@ -0,0 +1,34 @@
+From fad4e38079e91b13bf1e94732b7494504071b224 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Edward=20Tj=C3=B6rnhammar?= <ed@cflags.cc>
+Date: Sun, 28 Sep 2014 09:27:40 +0200
+Subject: [PATCH] catMaybes, explicitly use ClassyPrelude
+
+---
+ src/IHaskell/Eval/Completion.hs | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/IHaskell/Eval/Completion.hs b/src/IHaskell/Eval/Completion.hs
+index 790c903..93d7ac1 100644
+--- a/src/IHaskell/Eval/Completion.hs
++++ b/src/IHaskell/Eval/Completion.hs
+@@ -141,7 +141,7 @@ getTrueModuleName name = do
+       onlyImportDecl _ = Nothing
+ 
+   -- Get all imports that we use.
+-  imports <- catMaybes <$> map onlyImportDecl <$> getContext
++  imports <- ClassyPrelude.catMaybes <$> map onlyImportDecl <$> getContext
+ 
+   -- Find the ones that have a qualified name attached.
+   -- If this name isn't one of them, it already is the true name.
+@@ -178,7 +178,7 @@ completionType line loc target
+     = Empty
+ 
+   -- When in a string, complete filenames.
+-  | cursorInString line loc 
++  | cursorInString line loc
+     = FilePath (getStringTarget lineUpToCursor) (getStringTarget lineUpToCursor)
+ 
+   -- Complete module names in imports and elsewhere.
+-- 
+2.1.0
+