Initial checkin of HetMet / -XModalTypes modifications

[ghc-hetmet.git] / compiler / rename / RnExpr.lhs

diff --git a/compiler/rename/RnExpr.lhs b/compiler/rename/RnExpr.lhs
index 6d425d0..3a288bb 100644 (file)
--- a/compiler/rename/RnExpr.lhs
+++ b/compiler/rename/RnExpr.lhs
@@ -25,7 +25,7 @@ import RnBinds   ( rnLocalBindsAndThen, rnLocalValBindsLHS, rnLocalValBindsRHS,
                    rnMatchGroup, makeMiniFixityEnv) 
 import HsSyn
 import TcRnMonad
                    rnMatchGroup, makeMiniFixityEnv) 
 import HsSyn
 import TcRnMonad

-import TcEnv           ( thRnBrack )
+import TcEnv           ( thRnBrack, getHetMetLevel )

 import RnEnv
 import RnTypes         ( rnHsTypeFVs, rnSplice, checkTH,
                          mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec)
 import RnEnv
 import RnTypes         ( rnHsTypeFVs, rnSplice, checkTH,
                          mkOpFormRn, mkOpAppRn, mkNegAppRn, checkSectionPrec)

@@ -34,6 +34,7 @@ import DynFlags
 import BasicTypes      ( FixityDirection(..) )
 import PrelNames
 
 import BasicTypes      ( FixityDirection(..) )
 import PrelNames
 

+import Var              ( TyVar, varName )

 import Name
 import NameSet
 import RdrName
 import Name
 import NameSet
 import RdrName

@@ -84,6 +85,13 @@ rnExprs ls = rnExprs' ls emptyUniqSet
 Variables. We look up the variable and return the resulting name. 
 
 \begin{code}
 Variables. We look up the variable and return the resulting name. 
 
 \begin{code}

+
+-- during the renamer phase we only care about the length of the
+-- current HetMet level; the actual tyvars don't
+-- matter, so we use bottoms for them
+dummyTyVar :: TyVar
+dummyTyVar = error "tried to force RnExpr.dummyTyVar"
+

 rnLExpr :: LHsExpr RdrName -> RnM (LHsExpr Name, FreeVars)
 rnLExpr = wrapLocFstM rnExpr
 
 rnLExpr :: LHsExpr RdrName -> RnM (LHsExpr Name, FreeVars)
 rnLExpr = wrapLocFstM rnExpr
 

@@ -157,6 +165,21 @@ rnExpr (NegApp e _)
     mkNegAppRn e' neg_name     `thenM` \ final_e ->
     return (final_e, fv_e `plusFV` fv_neg)
 
     mkNegAppRn e' neg_name     `thenM` \ final_e ->
     return (final_e, fv_e `plusFV` fv_neg)
 

+rnExpr (HsHetMetBrak c e)
+  = do { (e', fv_e) <- updLclEnv (\x -> x { tcl_hetMetLevel = dummyTyVar:(tcl_hetMetLevel x) }) $ rnLExpr e
+       ; return (HsHetMetBrak c e', fv_e)
+       }
+rnExpr (HsHetMetEsc c t e)
+  = do { (e', fv_e) <- updLclEnv (\x -> x { tcl_hetMetLevel = tail (tcl_hetMetLevel x) }) $ rnLExpr e
+       ; return (HsHetMetEsc c t e', fv_e)
+       }
+rnExpr (HsHetMetCSP c e)
+  = do { (e', fv_e) <- updLclEnv (\x -> x { tcl_hetMetLevel = tail (tcl_hetMetLevel x) }) $ rnLExpr e
+       ; return (HsHetMetCSP c e', fv_e)
+       }
+
+    
+

 ------------------------------------------
 -- Template Haskell extensions
 -- Don't ifdef-GHCI them because we want to fail gracefully
 ------------------------------------------
 -- Template Haskell extensions
 -- Don't ifdef-GHCI them because we want to fail gracefully

@@ -273,7 +296,9 @@ rnExpr (HsIf _ p b1 b2)
     ; rebind <- xoptM Opt_RebindableSyntax
     ; if not rebind
        then return (HsIf Nothing p' b1' b2', plusFVs [fvP, fvB1, fvB2])
     ; rebind <- xoptM Opt_RebindableSyntax
     ; if not rebind
        then return (HsIf Nothing p' b1' b2', plusFVs [fvP, fvB1, fvB2])

-       else do { c <- liftM HsVar (lookupOccRn (mkVarUnqual (fsLit "ifThenElse")))
+       else do { hetMetLevel <- getHetMetLevel
+               ; n <- lookupOccRn $ mkRdrUnqual $ setOccNameDepth (length hetMetLevel) (mkVarOccFS (fsLit "ifThenElse"))
+               ; c <- return $ HsVar n

                ; return (HsIf (Just c) p' b1' b2', plusFVs [fvP, fvB1, fvB2]) }}
 
 rnExpr (HsType a)
                ; return (HsIf (Just c) p' b1' b2', plusFVs [fvP, fvB1, fvB2]) }}
 
 rnExpr (HsType a)