extractMatchResult, combineMatchResults,
adjustMatchResult, adjustMatchResultDs,
mkCoLetMatchResult, mkGuardedMatchResult,
- matchCanFail,
+ matchCanFail, mkEvalMatchResult,
mkCoPrimCaseMatchResult, mkCoAlgCaseMatchResult,
wrapBind, wrapBinds,
import {-# SOURCE #-} DsExpr( dsExpr )
import HsSyn
-import TcHsSyn ( hsPatType )
+import TcHsSyn ( hsLPatType, hsPatType )
import CoreSyn
import Constants ( mAX_TUPLE_SIZE )
import DsMonad
import CoreUtils ( exprType, mkIfThenElse, mkCoerce, bindNonRec )
-import MkId ( iRREFUT_PAT_ERROR_ID, mkReboxingAlt, mkNewTypeBody )
+import MkId ( iRREFUT_PAT_ERROR_ID, mkReboxingAlt, unwrapNewTypeBody )
import Id ( idType, Id, mkWildId, mkTemplateLocals, mkSysLocal )
import Var ( Var )
import Name ( Name )
import Literal ( Literal(..), mkStringLit, inIntRange, tARGET_MAX_INT )
-import TyCon ( isNewTyCon, tyConDataCons )
-import DataCon ( DataCon, dataConSourceArity, dataConTyCon, dataConTag )
-import Type ( mkFunTy, isUnLiftedType, Type, splitTyConApp, mkTyVarTy )
+import TyCon ( isNewTyCon, tyConDataCons, tyConArity )
+import DataCon ( DataCon, dataConSourceArity, dataConTyCon, dataConTag, dataConRepArgTys )
+import Type ( mkFunTy, isUnLiftedType, Type, splitTyConApp, mkTyVarTy,
+ splitNewTyConApp )
+import Coercion ( Coercion, mkUnsafeCoercion )
import TcType ( tcEqType )
import TysPrim ( intPrimTy )
import TysWiredIn ( nilDataCon, consDataCon,
\begin{code}
selectSimpleMatchVarL :: LPat Id -> DsM Id
-selectSimpleMatchVarL pat = selectMatchVar (unLoc pat) (hsPatType pat)
+selectSimpleMatchVarL pat = selectMatchVar (unLoc pat)
-- (selectMatchVars ps tys) chooses variables of type tys
-- to use for matching ps against. If the pattern is a variable,
-- we try to use that, to save inventing lots of fresh variables.
--- But even if it is a variable, its type might not match. Consider
+--
+-- OLD, but interesting note:
+-- But even if it is a variable, its type might not match. Consider
-- data T a where
-- T1 :: Int -> T Int
-- T2 :: a -> T a
-- f :: T a -> a -> Int
-- f (T1 i) (x::Int) = x
-- f (T2 i) (y::a) = 0
--- Then we must not choose (x::Int) as the matching variable!
-
-selectMatchVars :: [Pat Id] -> [Type] -> DsM [Id]
-selectMatchVars [] [] = return []
-selectMatchVars (p:ps) (ty:tys) = do { v <- selectMatchVar p ty
- ; vs <- selectMatchVars ps tys
- ; return (v:vs) }
-
-selectMatchVar (BangPat pat) pat_ty = selectMatchVar (unLoc pat) pat_ty
-selectMatchVar (LazyPat pat) pat_ty = selectMatchVar (unLoc pat) pat_ty
-selectMatchVar (VarPat var) pat_ty = try_for var pat_ty
-selectMatchVar (AsPat var pat) pat_ty = try_for (unLoc var) pat_ty
-selectMatchVar other_pat pat_ty = newSysLocalDs pat_ty -- OK, better make up one...
-
-try_for var pat_ty
- | idType var `tcEqType` pat_ty = returnDs var
- | otherwise = newSysLocalDs pat_ty
+-- Then we must not choose (x::Int) as the matching variable!
+-- And nowadays we won't, because the (x::Int) will be wrapped in a CoPat
+
+selectMatchVars :: [Pat Id] -> DsM [Id]
+selectMatchVars ps = mapM selectMatchVar ps
+
+selectMatchVar (BangPat pat) = selectMatchVar (unLoc pat)
+selectMatchVar (LazyPat pat) = selectMatchVar (unLoc pat)
+selectMatchVar (ParPat pat) = selectMatchVar (unLoc pat)
+selectMatchVar (VarPat var) = return var
+selectMatchVar (AsPat var pat) = return (unLoc var)
+selectMatchVar other_pat = newSysLocalDs (hsPatType other_pat)
+ -- OK, better make up one...
\end{code}
combineMatchResults match_result1@(MatchResult CantFail body_fn1) match_result2
= match_result1
-adjustMatchResult :: (CoreExpr -> CoreExpr) -> MatchResult -> MatchResult
+adjustMatchResult :: DsWrapper -> MatchResult -> MatchResult
adjustMatchResult encl_fn (MatchResult can_it_fail body_fn)
= MatchResult can_it_fail (\fail -> body_fn fail `thenDs` \ body ->
returnDs (encl_fn body))
[(DEFAULT, [], body)]
mkCoLetMatchResult :: CoreBind -> MatchResult -> MatchResult
-mkCoLetMatchResult bind match_result
- = adjustMatchResult (mkDsLet bind) match_result
+mkCoLetMatchResult bind = adjustMatchResult (mkDsLet bind)
+
+mkEvalMatchResult :: Id -> Type -> MatchResult -> MatchResult
+mkEvalMatchResult var ty
+ = adjustMatchResult (\e -> Case (Var var) var ty [(DEFAULT, [], e)])
mkGuardedMatchResult :: CoreExpr -> MatchResult -> MatchResult
mkGuardedMatchResult pred_expr (MatchResult can_it_fail body_fn)
-- Stuff for newtype
(con1, arg_ids1, match_result1) = head match_alts
arg_id1 = head arg_ids1
- newtype_rhs = mkNewTypeBody tycon (idType arg_id1) (Var var)
+ var_ty = idType var
+ (tc, ty_args) = splitNewTyConApp var_ty
+ newtype_rhs = unwrapNewTypeBody tc ty_args (Var var)
-- Stuff for data types
data_cons = tyConDataCons tycon
--
-- So to get the type of 'v', use the pattern not the rhs. Often more
-- efficient too.
- newSysLocalDs (hsPatType pat) `thenDs` \ val_var ->
+ newSysLocalDs (hsLPatType pat) `thenDs` \ val_var ->
-- For the error message we make one error-app, to avoid duplication.
-- But we need it at different types... so we use coerce for that
(Var bndr_var) error_expr `thenDs` \ rhs_expr ->
returnDs (bndr_var, rhs_expr)
where
- error_expr = mkCoerce (idType bndr_var) (Var err_var)
+ error_expr = mkCoerce co (Var err_var)
+ co = mkUnsafeCoercion (exprType (Var err_var)) (idType bndr_var)
is_simple_lpat p = is_simple_pat (unLoc p)
- is_simple_pat (TuplePat ps Boxed _) = all is_triv_lpat ps
- is_simple_pat (ConPatOut _ _ _ _ ps _) = all is_triv_lpat (hsConArgs ps)
- is_simple_pat (VarPat _) = True
- is_simple_pat (ParPat p) = is_simple_lpat p
- is_simple_pat other = False
+ is_simple_pat (TuplePat ps Boxed _) = all is_triv_lpat ps
+ is_simple_pat (ConPatOut{ pat_args = ps }) = all is_triv_lpat (hsConArgs ps)
+ is_simple_pat (VarPat _) = True
+ is_simple_pat (ParPat p) = is_simple_lpat p
+ is_simple_pat other = False
is_triv_lpat p = is_triv_pat (unLoc p)