import DsGRHSs ( dsGuarded )
import DsCCall ( dsCCall )
import DsListComp ( dsListComp )
-import DsUtils ( mkErrorAppDs )
+import DsUtils ( mkErrorAppDs, mkDsLets, mkConsExpr, mkNilExpr )
import Match ( matchWrapper, matchSimply )
import CoreUtils ( coreExprType )
import Const ( Con(..) )
import DataCon ( DataCon, dataConId, dataConTyCon, dataConArgTys, dataConFieldLabels )
import Const ( mkMachInt, Literal(..), mkStrLit )
-import PrelVals ( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID )
+import PrelInfo ( rEC_CON_ERROR_ID, rEC_UPD_ERROR_ID, iRREFUT_PAT_ERROR_ID )
import TyCon ( isNewTyCon )
import DataCon ( isExistentialDataCon )
import Type ( splitFunTys, mkTyConApp,
- splitAlgTyConApp, splitTyConApp_maybe,
+ splitAlgTyConApp, splitTyConApp_maybe, isNotUsgTy, unUsgTy,
splitAppTy, isUnLiftedType, Type
)
import TysWiredIn ( tupleCon, unboxedTupleCon,
- consDataCon, listTyCon, mkListTy,
+ listTyCon, mkListTy,
charDataCon, charTy, stringTy
)
import BasicTypes ( RecFlag(..) )
%* *
%************************************************************************
-@dsLet@ is a match-result transformer, taking the MatchResult for the body
+@dsLet@ is a match-result transformer, taking the @MatchResult@ for the body
and transforming it into one for the let-bindings enclosing the body.
This may seem a bit odd, but (source) let bindings can contain unboxed
binds like
-
+\begin{verbatim}
C x# = e
-
+\end{verbatim}
This must be transformed to a case expression and, if the type has
more than one constructor, may fail.
dsLet b1 body'
-- Special case for bindings which bind unlifted variables
-dsLet (MonoBind (AbsBinds [] [] binder_triples (PatMonoBind pat grhss loc)) sigs is_rec) body
+-- Silently ignore INLINE pragmas...
+dsLet (MonoBind (AbsBinds [] [] binder_triples inlines
+ (PatMonoBind pat grhss loc)) sigs is_rec) body
| or [isUnLiftedType (idType g) | (_, g, l) <- binder_triples]
= ASSERT (case is_rec of {NonRecursive -> True; other -> False})
putSrcLocDs loc $
bind (tyvars, g, l) body = ASSERT( null tyvars )
bindNonRec g (Var l) body
in
- mkErrorAppDs iRREFUT_PAT_ERROR_ID result_ty (showSDoc (ppr pat)) `thenDs` \ error_expr ->
+ mkErrorAppDs iRREFUT_PAT_ERROR_ID result_ty (showSDoc (ppr pat))
+ `thenDs` \ error_expr ->
matchSimply rhs PatBindMatch pat body' error_expr
where
result_ty = coreExprType body
= dsMonoBinds NoSccs binds [] `thenDs` \ prs ->
case is_rec of
Recursive -> returnDs (Let (Rec prs) body)
- NonRecursive -> returnDs (foldr mk_let body prs)
- where
- mk_let (bndr,rhs) body = Let (NonRec bndr rhs) body
+ NonRecursive -> returnDs (mkDsLets [NonRec b r | (b,r) <- prs] body)
\end{code}
%************************************************************************
%* *
%************************************************************************
-We give int/float literals type Integer and Rational, respectively.
+We give int/float literals type @Integer@ and @Rational@, respectively.
The typechecker will (presumably) have put \tr{from{Integer,Rational}s}
around them.
-ToDo: put in range checks for when converting "i"
+ToDo: put in range checks for when converting ``@i@''
(or should that be in the typechecker?)
For numeric literals, we try to detect there use at a standard type
-(Int, Float, etc.) are directly put in the right constructor.
+(@Int@, @Float@, etc.) are directly put in the right constructor.
[NB: down with the @App@ conversion.]
-Otherwise, we punt, putting in a "NoRep" Core literal (where the
+Otherwise, we punt, putting in a @NoRep@ Core literal (where the
representation decisions are delayed)...
See also below where we look for @DictApps@ for \tr{plusInt}, etc.
= let
the_char = mkConApp charDataCon [mkLit (MachChar (_HEAD_ s))]
the_nil = mkNilExpr charTy
- the_cons = mkConApp consDataCon [Type charTy, the_char, the_nil]
+ the_cons = mkConsExpr charTy the_char the_nil
in
returnDs the_cons
= returnDs (mkLit (NoRepStr str stringTy))
dsExpr (HsLitOut (HsLitLit str) ty)
+ | isUnLiftedType ty
+ = returnDs (mkLit (MachLitLit str ty))
+ | otherwise
= case (maybeBoxedPrimType ty) of
Just (boxing_data_con, prim_ty) ->
returnDs ( mkConApp boxing_data_con [mkLit (MachLitLit str prim_ty)] )
dsExpr (OpApp e1 op _ e2)
= dsExpr op `thenDs` \ core_op ->
-- for the type of y, we need the type of op's 2nd argument
- let
- (x_ty:y_ty:_, _) = splitFunTys (coreExprType core_op)
- in
dsExpr e1 `thenDs` \ x_core ->
dsExpr e2 `thenDs` \ y_core ->
returnDs (mkApps core_op [x_core, y_core])
dsExpr (HsCase discrim matches@[Match _ [TuplePat ps boxed] _ _] src_loc)
| not boxed && all var_pat ps
= putSrcLocDs src_loc $
- dsExpr discrim `thenDs` \ core_discrim ->
- matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
+ dsExpr discrim `thenDs` \ core_discrim ->
+ matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
case matching_code of
Case (Var x) bndr alts | x == discrim_var ->
returnDs (Case core_discrim bndr alts)
dsExpr (HsCase discrim matches src_loc)
= putSrcLocDs src_loc $
- dsExpr discrim `thenDs` \ core_discrim ->
- matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
+ dsExpr discrim `thenDs` \ core_discrim ->
+ matchWrapper CaseMatch matches "case" `thenDs` \ ([discrim_var], matching_code) ->
returnDs (bindNonRec discrim_var core_discrim matching_code)
dsExpr (HsLet binds body)
\end{code}
-Type lambda and application
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\noindent
+\underline{\bf Type lambda and application}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
dsExpr (TyLam tyvars expr)
= dsExpr expr `thenDs` \ core_expr ->
\end{code}
-Various data construction things
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\noindent
+\underline{\bf Various data construction things}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
\begin{code}
dsExpr (ExplicitListOut ty xs)
= go xs
go [] = returnDs (mkNilExpr ty)
go (x:xs) = dsExpr x `thenDs` \ core_x ->
go xs `thenDs` \ core_xs ->
- returnDs (mkConApp consDataCon [Type ty, core_x, core_xs])
+ ASSERT( isNotUsgTy ty )
+ returnDs (mkConsExpr ty core_x core_xs)
dsExpr (ExplicitTuple expr_list boxed)
= mapDs dsExpr expr_list `thenDs` \ core_exprs ->
returnDs (mkConApp ((if boxed
then tupleCon
else unboxedTupleCon) (length expr_list))
- (map (Type . coreExprType) core_exprs ++ core_exprs))
+ (map (Type . unUsgTy . coreExprType) core_exprs ++ core_exprs))
+ -- the above unUsgTy is *required* -- KSW 1999-04-07
dsExpr (HsCon con_id [ty] [arg])
| isNewTyCon tycon
= dsExpr arg `thenDs` \ arg' ->
- returnDs (Note (Coerce result_ty (coreExprType arg')) arg')
+ returnDs (Note (Coerce result_ty (unUsgTy (coreExprType arg'))) arg')
where
result_ty = mkTyConApp tycon [ty]
tycon = dataConTyCon con_id
dsExpr (HsCon con_id tys args)
= mapDs dsExpr args `thenDs` \ args2 ->
+ ASSERT( all isNotUsgTy tys )
returnDs (mkConApp con_id (map Type tys ++ args2))
dsExpr (ArithSeqOut expr (From from))
returnDs (mkApps expr2 [from2, thn2, two2])
\end{code}
-Record construction and update
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+\noindent
+\underline{\bf Record construction and update}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For record construction we do this (assuming T has three arguments)
-
+\begin{verbatim}
T { op2 = e }
==>
let err = /\a -> recConErr a
T (recConErr t1 "M.lhs/230/op1")
e
(recConErr t1 "M.lhs/230/op3")
-
-recConErr then converts its arugment string into a proper message
+\end{verbatim}
+@recConErr@ then converts its arugment string into a proper message
before printing it as
-
+\begin{verbatim}
M.lhs, line 230: missing field op1 was evaluated
+\end{verbatim}
+We also handle @C{}@ as valid construction syntax for an unlabelled
+constructor @C@, setting all of @C@'s fields to bottom.
\begin{code}
dsExpr (RecordConOut data_con con_expr rbinds)
(rhs:rhss) -> ASSERT( null rhss )
dsExpr rhs
[] -> mkErrorAppDs rEC_CON_ERROR_ID arg_ty (showSDoc (ppr lbl))
+ unlabelled_bottom arg_ty = mkErrorAppDs rEC_CON_ERROR_ID arg_ty ""
+
+ labels = dataConFieldLabels data_con
in
- mapDs mk_arg (zipEqual "dsExpr:RecordCon" arg_tys (dataConFieldLabels data_con)) `thenDs` \ con_args ->
+
+ (if null labels
+ then mapDs unlabelled_bottom arg_tys
+ else mapDs mk_arg (zipEqual "dsExpr:RecordCon" arg_tys labels))
+ `thenDs` \ con_args ->
+
returnDs (mkApps con_expr' con_args)
\end{code}
Record update is a little harder. Suppose we have the decl:
-
+\begin{verbatim}
data T = T1 {op1, op2, op3 :: Int}
| T2 {op4, op2 :: Int}
| T3
-
+\end{verbatim}
Then we translate as follows:
-
+\begin{verbatim}
r { op2 = e }
===>
let op2 = e in
T1 op1 _ op3 -> T1 op1 op2 op3
T2 op4 _ -> T2 op4 op2
other -> recUpdError "M.lhs/230"
-
-It's important that we use the constructor Ids for T1, T2 etc on the
-RHSs, and do not generate a Core Con directly, because the constructor
+\end{verbatim}
+It's important that we use the constructor Ids for @T1@, @T2@ etc on the
+RHSs, and do not generate a Core @Con@ directly, because the constructor
might do some argument-evaluation first; and may have to throw away some
dictionaries.
ok (sel_id, _, _) = recordSelectorFieldLabel sel_id `elem` con_fields
\end{code}
-Dictionary lambda and application
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+\noindent
+\underline{\bf Dictionary lambda and application}
+% ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@DictLam@ and @DictApp@ turn into the regular old things.
(OLD:) @DictFunApp@ also becomes a curried application, albeit slightly more
complicated; reminiscent of fully-applied constructors.
go (GuardStmt expr locn : stmts)
= do_expr expr locn `thenDs` \ expr2 ->
go stmts `thenDs` \ rest ->
- let msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn) in
+ let msg = ASSERT( isNotUsgTy b_ty )
+ "Pattern match failure in do expression, " ++ showSDoc (ppr locn) in
returnDs (mkIfThenElse expr2
rest
(App (App (Var fail_id)
go (ExprStmt expr locn : stmts)
= do_expr expr locn `thenDs` \ expr2 ->
let
- (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a)
+ (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a)
in
if null stmts then
returnDs expr2
= putSrcLocDs locn $
dsExpr expr `thenDs` \ expr2 ->
let
- (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a)
- fail_expr = HsApp (TyApp (HsVar fail_id) [b_ty]) (HsLitOut (HsString (_PK_ msg)) stringTy)
- msg = "Pattern match failure in do expression, " ++ showSDoc (ppr locn)
+ (_, a_ty) = splitAppTy (coreExprType expr2) -- Must be of form (m a)
+ fail_expr = HsApp (TyApp (HsVar fail_id) [b_ty])
+ (HsLitOut (HsString (_PK_ msg)) stringTy)
+ msg = ASSERT2( isNotUsgTy a_ty, ppr a_ty )
+ ASSERT2( isNotUsgTy b_ty, ppr b_ty )
+ "Pattern match failure in do expression, " ++ showSDoc (ppr locn)
main_match = mkSimpleMatch [pat]
- (HsDoOut do_or_lc stmts return_id then_id fail_id result_ty locn)
+ (HsDoOut do_or_lc stmts return_id then_id
+ fail_id result_ty locn)
(Just result_ty) locn
the_matches
| failureFreePat pat = [main_match]