replace several 'fromJust's with 'expectJust's

[ghc-hetmet.git] / ghc / compiler / typecheck / TcBinds.lhs

diff --git a/ghc/compiler/typecheck/TcBinds.lhs b/ghc/compiler/typecheck/TcBinds.lhs
index c765699..cffcb9c 100644 (file)
--- a/ghc/compiler/typecheck/TcBinds.lhs
+++ b/ghc/compiler/typecheck/TcBinds.lhs
@@ -62,7 +62,7 @@ import SrcLoc         ( Located(..), unLoc, getLoc )
 import Bag
 import ErrUtils                ( Message )
 import Digraph         ( SCC(..), stronglyConnComp )
-import Maybes          ( fromJust, isJust, isNothing, orElse )
+import Maybes          ( expectJust, isJust, isNothing, orElse )
 import Util            ( singleton )
 import BasicTypes      ( TopLevelFlag(..), isTopLevel, isNotTopLevel,
                          RecFlag(..), isNonRec, InlineSpec, defaultInlineSpec )
@@ -251,10 +251,8 @@ mkEdges :: TcSigFun -> LHsBinds Name
 type BKey  = Int -- Just number off the bindings
 
 mkEdges sig_fn binds
-  = [ (bind, key, [fromJust mb_key | n <- nameSetToList (bind_fvs (unLoc bind)),
-                                    let mb_key = lookupNameEnv key_map n,
-                                    isJust mb_key,
-                                    no_sig n ])
+  = [ (bind, key, [key | n <- nameSetToList (bind_fvs (unLoc bind)),
+                        Just key <- [lookupNameEnv key_map n], no_sig n ])
     | (bind, key) <- keyd_binds
     ]
   where
@@ -419,7 +417,8 @@ type TcPragFun = Name -> [LSig Name]
 mkPragFun :: [LSig Name] -> TcPragFun
 mkPragFun sigs = \n -> lookupNameEnv env n `orElse` []
        where
-         prs = [(fromJust (sigName sig), sig) | sig <- sigs, isPragLSig sig]
+         prs = [(expectJust "mkPragFun" (sigName sig), sig) 
+               | sig <- sigs, isPragLSig sig]
          env = foldl add emptyNameEnv prs
          add env (n,p) = extendNameEnv_Acc (:) singleton env n p
 
@@ -958,7 +957,7 @@ mkSigFun :: [LSig Name] -> TcSigFun
 -- Precondition: no duplicates
 mkSigFun sigs = lookupNameEnv env
   where
-    env = mkNameEnv [(fromJust (sigName sig), sig) | sig <- sigs]
+    env = mkNameEnv [(expectJust "mkSigFun" (sigName sig), sig) | sig <- sigs]
 
 ---------------
 data TcSigInfo