mkSelectorBinds,
mkTupleBind,
mkTupleExpr,
+ mkTupleSelector,
selectMatchVars,
showForErr
) where
import HsSyn ( HsExpr(..), OutPat(..), HsLit(..), Fixity,
Match, HsBinds, Stmt, DoOrListComp, HsType, ArithSeqInfo )
import TcHsSyn ( SYN_IE(TypecheckedPat) )
-import DsHsSyn ( outPatType )
+import DsHsSyn ( outPatType, collectTypedPatBinders )
import CoreSyn
import DsMonad
import CoreUtils ( coreExprType, mkCoreIfThenElse )
import PprStyle ( PprStyle(..) )
import PrelVals ( iRREFUT_PAT_ERROR_ID, voidId )
-import Pretty ( ppShow, ppBesides, ppStr )
+import Pretty ( Doc, hcat, text )
import Id ( idType, dataConArgTys,
-- pprId{-ToDo:rm-},
SYN_IE(DataCon), SYN_IE(DictVar), SYN_IE(Id), GenId )
import Literal ( Literal(..) )
import PprType ( GenType, GenTyVar )
+import PrimOp ( PrimOp )
import TyCon ( isNewTyCon, tyConDataCons )
import Type ( mkTyVarTys, mkRhoTy, mkForAllTys, mkFunTy,
mkTheta, isUnboxedType, applyTyCon, getAppTyCon,
- GenType {- instances -}
+ GenType {- instances -}, SYN_IE(Type)
)
-import TyVar ( GenTyVar {- instances -} )
+import TyVar ( GenTyVar {- instances -}, SYN_IE(TyVar) )
import TysPrim ( voidTy )
import TysWiredIn ( tupleTyCon, unitDataCon, tupleCon )
import UniqSet ( mkUniqSet, minusUniqSet, uniqSetToList, SYN_IE(UniqSet) )
import Unique ( Unique )
import Usage ( SYN_IE(UVar) )
import SrcLoc ( SrcLoc {- instance Outputable -} )
+#if __GLASGOW_HASKELL__ >= 202
+import Outputable
+#endif
+
+\end{code}
+
+
+%************************************************************************
+%* *
+%* Selecting match variables
+%* *
+%************************************************************************
+
+We're about to match against some patterns. We want to make some
+@Ids@ to use as match variables. If a pattern has an @Id@ readily at
+hand, which should indeed be bound to the pattern as a whole, then use it;
+otherwise, make one up.
+
+\begin{code}
+selectMatchVars :: [TypecheckedPat] -> DsM [Id]
+selectMatchVars pats
+ = mapDs var_from_pat_maybe pats
+ where
+ var_from_pat_maybe (VarPat var) = returnDs var
+ var_from_pat_maybe (AsPat var pat) = returnDs var
+ var_from_pat_maybe (LazyPat pat) = var_from_pat_maybe pat
+ var_from_pat_maybe other_pat
+ = newSysLocalDs (outPatType other_pat) -- OK, better make up one...
\end{code}
+
%************************************************************************
%* *
%* type synonym EquationInfo and access functions for its pieces *
\begin{code}
showForErr :: Outputable a => a -> String -- Boring but useful
-showForErr thing = ppShow 80 (ppr PprForUser thing)
+showForErr thing = show (ppr PprQuote thing)
mkErrorAppDs :: Id -- The error function
-> Type -- Type to which it should be applied
mkErrorAppDs err_id ty msg
= getSrcLocDs `thenDs` \ src_loc ->
let
- full_msg = ppShow 80 (ppBesides [ppr PprForUser src_loc, ppStr "|", ppStr msg])
+ full_msg = show (hcat [ppr PprForUser src_loc, text "|", text msg])
msg_lit = NoRepStr (_PK_ full_msg)
in
returnDs (mkApp (Var err_id) [] [ty] [LitArg msg_lit])
expressions.
\begin{code}
-mkSelectorBinds :: [TyVar] -- Variables wrt which the pattern is polymorphic
- -> TypecheckedPat -- The pattern
- -> [(Id,Id)] -- Monomorphic and polymorphic binders for
- -- the pattern
- -> CoreExpr -- Expression to which the pattern is bound
+mkSelectorBinds :: TypecheckedPat -- The pattern
+ -> CoreExpr -- Expression to which the pattern is bound
-> DsM [(Id,CoreExpr)]
-mkSelectorBinds tyvars pat locals_and_globals val_expr
- = if is_simple_tuple_pat pat then
- mkTupleBind tyvars [] locals_and_globals val_expr
- else
- mkErrorAppDs iRREFUT_PAT_ERROR_ID res_ty pat_string `thenDs` \ error_msg ->
- matchSimply val_expr pat res_ty local_tuple error_msg `thenDs` \ tuple_expr ->
- mkTupleBind tyvars [] locals_and_globals tuple_expr
+mkSelectorBinds (VarPat v) val_expr
+ = returnDs [(v, val_expr)]
+
+mkSelectorBinds pat val_expr
+ | is_simple_tuple_pat pat
+ = mkTupleBind binders val_expr
+
+ | otherwise
+ = mkErrorAppDs iRREFUT_PAT_ERROR_ID res_ty pat_string `thenDs` \ error_msg ->
+ matchSimply val_expr pat res_ty local_tuple error_msg `thenDs` \ tuple_expr ->
+ mkTupleBind binders tuple_expr
+
where
- locals = [local | (local, _) <- locals_and_globals]
- local_tuple = mkTupleExpr locals
+ binders = collectTypedPatBinders pat
+ local_tuple = mkTupleExpr binders
res_ty = coreExprType local_tuple
is_simple_tuple_pat (TuplePat ps) = all is_var_pat ps
is_var_pat (VarPat v) = True
is_var_pat other = False -- Even wild-card patterns aren't acceptable
- pat_string = ppShow 80 (ppr PprForUser pat)
+ pat_string = show (ppr PprForUser pat)
\end{code}
-We're about to match against some patterns. We want to make some
-@Ids@ to use as match variables. If a pattern has an @Id@ readily at
-hand, which should indeed be bound to the pattern as a whole, then use it;
-otherwise, make one up.
-\begin{code}
-selectMatchVars :: [TypecheckedPat] -> DsM [Id]
-selectMatchVars pats
- = mapDs var_from_pat_maybe pats
- where
- var_from_pat_maybe (VarPat var) = returnDs var
- var_from_pat_maybe (AsPat var pat) = returnDs var
- var_from_pat_maybe (LazyPat pat) = var_from_pat_maybe pat
- var_from_pat_maybe other_pat
- = newSysLocalDs (outPatType other_pat) -- OK, better make up one...
-\end{code}
\begin{code}
-mkTupleBind :: [TyVar] -- Abstract wrt these...
- -> [DictVar] -- ... and these
-
- -> [(Id, Id)] -- Local, global pairs, equal in number
- -- to the size of the tuple. The types
- -- of the globals is the generalisation of
- -- the corresp local, wrt the tyvars and dicts
+mkTupleBind :: [Id] -- Names of tuple components
+ -> CoreExpr -- Expr whose value is a tuple of correct type
+ -> DsM [(Id, CoreExpr)] -- Bindings for the globals
- -> CoreExpr -- Expr whose value is a tuple; the expression
- -- may mention the tyvars and dicts
-
- -> DsM [(Id, CoreExpr)] -- Bindings for the globals
-\end{code}
-The general call is
-\begin{verbatim}
- mkTupleBind tyvars dicts [(l1,g1), ..., (ln,gn)] tup_expr
-\end{verbatim}
-If $n=1$, the result is:
-\begin{verbatim}
- g1 = /\ tyvars -> \ dicts -> rhs
-\end{verbatim}
-Otherwise, the result is:
-\begin{verbatim}
- tup = /\ tyvars -> \ dicts -> tup_expr
- g1 = /\ tyvars -> \ dicts -> case (tup tyvars dicts) of
- (l1, ..., ln) -> l1
- ...etc...
-\end{verbatim}
+mkTupleBind [local] tuple_expr
+ = returnDs [(local, tuple_expr)]
-\begin{code}
-mkTupleBind tyvars dicts [(local,global)] tuple_expr
- = returnDs [(global, mkLam tyvars dicts tuple_expr)]
+mkTupleBind locals tuple_expr
+ = newSysLocalDs (coreExprType tuple_expr) `thenDs` \ tuple_var ->
+ let
+ mk_bind local = (local, mkTupleSelector locals local (Var tuple_var))
+ in
+ returnDs ( (tuple_var, tuple_expr) :
+ map mk_bind locals )
\end{code}
-The general case:
-
-\begin{code}
-mkTupleBind tyvars dicts local_global_prs tuple_expr
- = --pprTrace "mkTupleBind:\n" (ppAboves [ppCat (map (pprId PprShowAll) locals), ppCat (map (pprId PprShowAll) globals), {-ppr PprDebug local_tuple, pprType PprDebug res_ty,-} ppr PprDebug tuple_expr]) $
-
- newSysLocalDs tuple_var_ty `thenDs` \ tuple_var ->
-
- zipWithDs (mk_selector (Var tuple_var))
- local_global_prs
- [(0::Int) .. (length local_global_prs - 1)]
- `thenDs` \ tup_selectors ->
- returnDs (
- (tuple_var, mkLam tyvars dicts tuple_expr)
- : tup_selectors
- )
- where
- locals, globals :: [Id]
- locals = [local | (local,global) <- local_global_prs]
- globals = [global | (local,global) <- local_global_prs]
-
- no_of_binders = length local_global_prs
- tyvar_tys = mkTyVarTys tyvars
-
- tuple_var_ty :: Type
- tuple_var_ty
- = mkForAllTys tyvars $
- mkRhoTy theta $
- applyTyCon (tupleTyCon no_of_binders)
- (map idType locals)
- where
- theta = mkTheta (map idType dicts)
-
- mk_selector :: CoreExpr -> (Id, Id) -> Int -> DsM (Id, CoreExpr)
-
- mk_selector tuple_var_expr (local, global) which_local
- = mapDs duplicateLocalDs locals{-the whole bunch-} `thenDs` \ binders ->
- let
- selected = binders !! which_local
- in
- returnDs (
- global,
- mkLam tyvars dicts (
- mkTupleSelector
- (mkValApp (mkTyApp tuple_var_expr tyvar_tys)
- (map VarArg dicts))
- binders
- selected)
- )
-\end{code}
@mkTupleExpr@ builds a tuple; the inverse to @mkTupleSelector@. If it
has only one element, it is the identity function.
just the identity.
\begin{code}
-mkTupleSelector :: CoreExpr -- Scrutinee
- -> [Id] -- The tuple args
+mkTupleSelector :: [Id] -- The tuple args
-> Id -- The selected one
+ -> CoreExpr -- Scrutinee
-> CoreExpr
-mkTupleSelector expr [] the_var = panic "mkTupleSelector"
+mkTupleSelector [] the_var scrut = panic "mkTupleSelector"
-mkTupleSelector expr [var] should_be_the_same_var
+mkTupleSelector [var] should_be_the_same_var scrut
= ASSERT(var == should_be_the_same_var)
- expr
+ scrut
-mkTupleSelector expr vars the_var
- = Case expr (AlgAlts [(tupleCon arity, vars, Var the_var)]
+mkTupleSelector vars the_var scrut
+ = Case scrut (AlgAlts [(tupleCon arity, vars, Var the_var)]
NoDefault)
where
arity = length vars
projects / ghc-hetmet.git / blobdiff