[project @ 2003-10-30 09:03:15 by simonpj]

[ghc-hetmet.git] / ghc / compiler / deSugar / DsListComp.lhs

diff --git a/ghc/compiler/deSugar/DsListComp.lhs b/ghc/compiler/deSugar/DsListComp.lhs
index 713d026..fc3a689 100644 (file)
--- a/ghc/compiler/deSugar/DsListComp.lhs
+++ b/ghc/compiler/deSugar/DsListComp.lhs
@@ -11,7 +11,6 @@ module DsListComp ( dsListComp, dsPArrComp ) where
 import {-# SOURCE #-} DsExpr ( dsExpr, dsLet )
 
 import BasicTypes      ( Boxity(..) )
-import TyCon           ( tyConName )
 import HsSyn           ( Pat(..), HsExpr(..), Stmt(..),
                          HsMatchContext(..), HsStmtContext(..),
                          collectHsBinders )
@@ -22,7 +21,7 @@ import CoreSyn
 import DsMonad         -- the monadery used in the desugarer
 import DsUtils
 
-import CmdLineOpts     ( opt_IgnoreIfacePragmas, opt_RulesOff )
+import CmdLineOpts     ( DynFlag(..), dopt, opt_RulesOff )
 import CoreUtils       ( exprType, mkIfThenElse )
 import Id              ( idType )
 import Var              ( Id )
@@ -30,10 +29,10 @@ import Type         ( mkTyVarTy, mkFunTys, mkFunTy, Type,
                          splitTyConApp_maybe )
 import TysPrim         ( alphaTyVar )
 import TysWiredIn      ( nilDataCon, consDataCon, trueDataConId, falseDataConId, 
-                         unitDataConId, unitTy, mkListTy )
+                         unitDataConId, unitTy, mkListTy, parrTyCon )
 import Match           ( matchSimply )
 import PrelNames       ( foldrName, buildName, replicatePName, mapPName, 
-                         filterPName, zipPName, crossPName, parrTyConName ) 
+                         filterPName, zipPName, crossPName ) 
 import PrelInfo                ( pAT_ERROR_ID )
 import SrcLoc          ( noSrcLoc )
 import Panic           ( panic )
@@ -51,17 +50,19 @@ dsListComp :: [TypecheckedStmt]
           -> DsM CoreExpr
 
 dsListComp quals elt_ty
-  |  opt_RulesOff || opt_IgnoreIfacePragmas    -- Either rules are switched off, or
-                                               --   we are ignoring what there are;
-                                               --   Either way foldr/build won't happen, so
-                                               --   use the more efficient Wadler-style desugaring
-  || isParallelComp quals                      -- Foldr-style desugaring can't handle
-                                               --   parallel list comprehensions
-  = deListComp quals (mkNilExpr elt_ty)
-
-  | otherwise          -- Foldr/build should be enabled, so desugar 
-                       -- into foldrs and builds
-  = newTyVarsDs [alphaTyVar]    `thenDs` \ [n_tyvar] ->
+  = getDOptsDs  `thenDs` \dflags ->
+    if opt_RulesOff || dopt Opt_IgnoreInterfacePragmas dflags
+       -- Either rules are switched off, or we are ignoring what there are;
+       -- Either way foldr/build won't happen, so use the more efficient
+       -- Wadler-style desugaring
+       || isParallelComp quals
+               -- Foldr-style desugaring can't handle
+               -- parallel list comprehensions
+       then deListComp quals (mkNilExpr elt_ty)
+
+   else                -- Foldr/build should be enabled, so desugar 
+               -- into foldrs and builds
+    newTyVarsDs [alphaTyVar]    `thenDs` \ [n_tyvar] ->
     let
        n_ty = mkTyVarTy n_tyvar
         c_ty = mkFunTys [elt_ty, n_ty] n_ty
@@ -145,7 +146,7 @@ with the Unboxed variety.
 deListComp :: [TypecheckedStmt] -> CoreExpr -> DsM CoreExpr
 
 deListComp (ParStmt stmtss_w_bndrs : quals) list
-  = mapDs do_list_comp stmtss_w_bndrs  `thenDs` \ exps ->
+  = mappM do_list_comp stmtss_w_bndrs  `thenDs` \ exps ->
     mkZipBind qual_tys                 `thenDs` \ (zip_fn, zip_rhs) ->
 
        -- Deal with [e | pat <- zip l1 .. ln] in example above
@@ -231,9 +232,9 @@ mkZipBind :: [Type] -> DsM (Id, CoreExpr)
 --                             (a2:as'2) -> (a2,a2) : zip as'1 as'2)]
 
 mkZipBind elt_tys 
-  = mapDs newSysLocalDs  list_tys      `thenDs` \ ass ->
-    mapDs newSysLocalDs  elt_tys       `thenDs` \ as' ->
-    mapDs newSysLocalDs  list_tys      `thenDs` \ as's ->
+  = mappM newSysLocalDs  list_tys      `thenDs` \ ass ->
+    mappM newSysLocalDs  elt_tys       `thenDs` \ as' ->
+    mappM newSysLocalDs  list_tys      `thenDs` \ as's ->
     newSysLocalDs zip_fn_ty            `thenDs` \ zip_fn ->
     let 
        inner_rhs = mkConsExpr ret_elt_ty 
@@ -471,7 +472,7 @@ deLambda ty p e  =
 parrElemType   :: CoreExpr -> Type
 parrElemType e  = 
   case splitTyConApp_maybe (exprType e) of
-    Just (tycon, [ty]) | tyConName tycon == parrTyConName -> ty
+    Just (tycon, [ty]) | tycon == parrTyCon -> ty
     _                                                    -> panic
       "DsListComp.parrElemType: not a parallel array type"
 \end{code}