Removing the default grouping clause from the SQL-like comprehension notation ;

2 files changed, 11 insertions, 25 deletions

diff --git a/compiler/hsSyn/HsExpr.lhs b/compiler/hsSyn/HsExpr.lhs
index 7b814e14bb..af2de9f87b 100644
--- a/compiler/hsSyn/HsExpr.lhs
+++ b/compiler/hsSyn/HsExpr.lhs
@@ -943,12 +943,8 @@ data StmtLR idL idR
   deriving (Data, Typeable)
 
 data TransForm	 -- The 'f' below is the 'using' function, 'e' is the by function
-  = ThenForm	 -- then f          or    then f by e        (depending on trS_by)
-  | GroupFormU	 -- group using f   or    group using f by e (depending on trS_by)
-  | GroupFormB   -- group by e  
-      -- In the GroupByFormB, trS_using is filled in with
-      --    'groupWith' (list comprehensions) or 
-      --    'groupM' (monad comprehensions)
+  = ThenForm     -- then f               or    then f by e             (depending on trS_by)
+  | GroupForm	   -- then group using f   or    then group by e using f (depending on trS_by)
   deriving (Data, Typeable)
 \end{code}
 
@@ -1078,12 +1074,7 @@ expressions:
    =>
   guard exp >> [ body | stmts ]
 
-Grouping/parallel statements require the 'Control.Monad.Group.groupM' and
-'Control.Monad.Zip.mzip' functions:
-
-  [ body | stmts, then group by e, rest]
-   =>
-  groupM [ body | stmts ] >>= \bndrs -> [ body | rest ]
+Parallel statements require the 'Control.Monad.Zip.mzip' function:
 
   [ body | stmts1 | stmts2 | .. ]
    =>
@@ -1126,9 +1117,7 @@ pprTransStmt :: OutputableBndr id => Maybe (LHsExpr id)
 				  -> SDoc
 pprTransStmt by using ThenForm
   = sep [ ptext (sLit "then"), nest 2 (ppr using), nest 2 (pprBy by)]
-pprTransStmt by _ GroupFormB
-  = sep [ ptext (sLit "then group"), nest 2 (pprBy by) ]
-pprTransStmt by using GroupFormU
+pprTransStmt by using GroupForm
   = sep [ ptext (sLit "then group"), nest 2 (pprBy by), nest 2 (ptext (sLit "using") <+> ppr using)]
 
 pprBy :: OutputableBndr id => Maybe (LHsExpr id) -> SDoc
diff --git a/compiler/hsSyn/HsUtils.lhs b/compiler/hsSyn/HsUtils.lhs
index 207c2bc189..358f8bbc3e 100644
--- a/compiler/hsSyn/HsUtils.lhs
+++ b/compiler/hsSyn/HsUtils.lhs
@@ -51,7 +51,7 @@ module HsUtils(
 
   -- Stmts
   mkTransformStmt, mkTransformByStmt, mkExprStmt, mkBindStmt, mkLastStmt,
-  emptyTransStmt, mkGroupUsingStmt, mkGroupByStmt, mkGroupByUsingStmt, 
+  emptyTransStmt, mkGroupUsingStmt, mkGroupByUsingStmt, 
   emptyRecStmt, mkRecStmt, 
 
   -- Template Haskell
@@ -243,10 +243,9 @@ mkHsIf c a b = HsIf (Just noSyntaxExpr) c a b
 mkNPat lit neg     = NPat lit neg noSyntaxExpr
 mkNPlusKPat id lit = NPlusKPat id lit noSyntaxExpr noSyntaxExpr
 
-mkTransformStmt   :: [LStmt idL] -> LHsExpr idR                -> StmtLR idL idR
-mkTransformByStmt :: [LStmt idL] -> LHsExpr idR -> LHsExpr idR -> StmtLR idL idR
+mkTransformStmt    :: [LStmt idL] -> LHsExpr idR                -> StmtLR idL idR
+mkTransformByStmt  :: [LStmt idL] -> LHsExpr idR -> LHsExpr idR -> StmtLR idL idR
 mkGroupUsingStmt   :: [LStmt idL]                -> LHsExpr idR -> StmtLR idL idR
-mkGroupByStmt      :: [LStmt idL] -> LHsExpr idR                -> StmtLR idL idR
 mkGroupByUsingStmt :: [LStmt idL] -> LHsExpr idR -> LHsExpr idR -> StmtLR idL idR
 
 emptyTransStmt :: StmtLR idL idR
@@ -254,12 +253,10 @@ emptyTransStmt = TransStmt { trS_form = undefined, trS_stmts = [], trS_bndrs = [
                            , trS_by = Nothing, trS_using = noLoc noSyntaxExpr
                            , trS_ret = noSyntaxExpr, trS_bind = noSyntaxExpr
                            , trS_fmap = noSyntaxExpr }
-mkTransformStmt   ss u    = emptyTransStmt { trS_form = ThenForm, trS_stmts = ss, trS_using = u }
-mkTransformByStmt ss u b  = emptyTransStmt { trS_form = ThenForm, trS_stmts = ss, trS_using = u, trS_by = Just b }
-mkGroupByStmt      ss b   = emptyTransStmt { trS_form = GroupFormB, trS_stmts = ss, trS_by = Just b }
-mkGroupUsingStmt   ss u   = emptyTransStmt { trS_form = GroupFormU, trS_stmts = ss, trS_using = u }
-mkGroupByUsingStmt ss b u = emptyTransStmt { trS_form = GroupFormU, trS_stmts = ss
-                                           , trS_by = Just b, trS_using = u }
+mkTransformStmt    ss u   = emptyTransStmt { trS_form = ThenForm,  trS_stmts = ss, trS_using = u }
+mkTransformByStmt  ss u b = emptyTransStmt { trS_form = ThenForm,  trS_stmts = ss, trS_using = u, trS_by = Just b }
+mkGroupUsingStmt   ss u   = emptyTransStmt { trS_form = GroupForm, trS_stmts = ss, trS_using = u }
+mkGroupByUsingStmt ss b u = emptyTransStmt { trS_form = GroupForm, trS_stmts = ss, trS_using = u, trS_by = Just b }
 
 mkLastStmt expr	    = LastStmt expr noSyntaxExpr
 mkExprStmt expr	    = ExprStmt expr noSyntaxExpr noSyntaxExpr placeHolderType