#include "HsVersions.h"
-import {-# SOURCE #-} TcExpr( tcExpr )
-
import HsSyn ( InPat(..), OutPat(..), HsLit(..), HsExpr(..), Sig(..) )
import RnHsSyn ( RenamedPat )
import TcHsSyn ( TcPat, TcId )
import TcMonad
import Inst ( Inst, OverloadedLit(..), InstOrigin(..),
emptyLIE, plusLIE, LIE,
- newMethod, newOverloadedLit,
- newDicts, instToIdBndr
+ newMethod, newOverloadedLit, newDicts, newClassDicts
)
import Name ( Name, getOccName, getSrcLoc )
import FieldLabel ( fieldLabelName )
-import TcEnv ( tcLookupValue,
+import TcEnv ( tcLookupValue, tcLookupClassByKey,
tcLookupValueByKey, newLocalId, badCon
)
-import TcType ( TcType, TcTyVar, tcInstTyVars )
-import TcMonoType ( tcHsType )
-import TcUnify ( unifyTauTy, unifyListTy,
- unifyTupleTy, unifyUnboxedTupleTy
- )
+import TcType ( TcType, TcTyVar, tcInstTyVars, newTyVarTy )
+import TcMonoType ( tcHsSigType )
+import TcUnify ( unifyTauTy, unifyListTy, unifyTupleTy )
-import Bag ( Bag )
import CmdLineOpts ( opt_IrrefutableTuples )
-import DataCon ( DataCon, dataConSig, dataConFieldLabels, dataConSourceArity )
-import Id ( Id, idType, isDataConId_maybe )
-import Type ( Type, isTauTy, mkTyConApp )
-import Subst ( substTy, substTheta )
+import DataCon ( DataCon, dataConSig, dataConFieldLabels,
+ dataConSourceArity
+ )
+import Id ( Id, idType, isDataConWrapId_maybe )
+import Type ( Type, isTauTy, mkTyConApp, mkClassPred, boxedTypeKind )
+import Subst ( substTy, substClasses )
import TysPrim ( charPrimTy, intPrimTy, floatPrimTy,
doublePrimTy, addrPrimTy
)
import TysWiredIn ( charTy, stringTy, intTy )
-import SrcLoc ( SrcLoc )
-import Unique ( eqClassOpKey, geClassOpKey, minusClassOpKey )
+import Unique ( eqClassOpKey, geClassOpKey, minusClassOpKey,
+ cCallableClassKey
+ )
+import BasicTypes ( isBoxed )
import Bag
import Util ( zipEqual )
import Outputable
tcPat tc_bndr (NegPatIn pat) pat_ty
= tcPat tc_bndr (negate_lit pat) pat_ty
where
- negate_lit (LitPatIn (HsInt i)) = LitPatIn (HsInt (-i))
- negate_lit (LitPatIn (HsFrac f)) = LitPatIn (HsFrac (-f))
- negate_lit _ = panic "TcPat:negate_pat"
+ negate_lit (LitPatIn (HsInt i)) = LitPatIn (HsInt (-i))
+ negate_lit (LitPatIn (HsIntPrim i)) = LitPatIn (HsIntPrim (-i))
+ negate_lit (LitPatIn (HsFrac f)) = LitPatIn (HsFrac (-f))
+ negate_lit (LitPatIn (HsFloatPrim f)) = LitPatIn (HsFloatPrim (-f))
+ negate_lit (LitPatIn (HsDoublePrim f)) = LitPatIn (HsDoublePrim (-f))
+ negate_lit _ = panic "TcPat:negate_pat"
tcPat tc_bndr (ParPatIn parend_pat) pat_ty
= tcPat tc_bndr parend_pat pat_ty
tcPat tc_bndr (SigPatIn pat sig) pat_ty
- = tcHsType sig `thenTc` \ sig_ty ->
+ = tcHsSigType sig `thenTc` \ sig_ty ->
-- Check that the signature isn't a polymorphic one, which
-- we don't permit (at present, anyway)
tcPats tc_bndr pats (repeat elem_ty) `thenTc` \ (pats', lie_req, tvs, ids, lie_avail) ->
returnTc (ListPat elem_ty pats', lie_req, tvs, ids, lie_avail)
-tcPat tc_bndr pat_in@(TuplePatIn pats boxed) pat_ty
+tcPat tc_bndr pat_in@(TuplePatIn pats boxity) pat_ty
= tcAddErrCtxt (patCtxt pat_in) $
- (if boxed
- then unifyTupleTy arity pat_ty
- else unifyUnboxedTupleTy arity pat_ty) `thenTc` \ arg_tys ->
-
- tcPats tc_bndr pats arg_tys `thenTc` \ (pats', lie_req, tvs, ids, lie_avail) ->
+ unifyTupleTy boxity arity pat_ty `thenTc` \ arg_tys ->
+ tcPats tc_bndr pats arg_tys `thenTc` \ (pats', lie_req, tvs, ids, lie_avail) ->
-- possibly do the "make all tuple-pats irrefutable" test:
let
- unmangled_result = TuplePat pats' boxed
+ unmangled_result = TuplePat pats' boxity
-- Under flag control turn a pattern (x,y,z) into ~(x,y,z)
-- so that we can experiment with lazy tuple-matching.
-- it was easy to do.
possibly_mangled_result
- | opt_IrrefutableTuples && boxed = LazyPat unmangled_result
- | otherwise = unmangled_result
+ | opt_IrrefutableTuples && isBoxed boxity = LazyPat unmangled_result
+ | otherwise = unmangled_result
in
returnTc (possibly_mangled_result, lie_req, tvs, ids, lie_avail)
where
-- Check the constructor itself
tcConstructor pat name pat_ty `thenTc` \ (data_con, ex_tvs, dicts, lie_avail1, arg_tys) ->
let
- field_tys = zipEqual "tcPat"
- (map fieldLabelName (dataConFieldLabels data_con))
- arg_tys
+ -- not zipEqual: if the constructor isn't really a record, then
+ -- dataConFieldLabels will be empty (and each field in the pattern
+ -- will generate an error below).
+ field_tys = zip (map fieldLabelName (dataConFieldLabels data_con))
+ arg_tys
in
-- Check the fields
= returnTc ([], emptyLIE, emptyBag, emptyBag, emptyLIE)
tc_fields field_tys ((field_label, rhs_pat, pun_flag) : rpats)
- | null matching_fields
- = addErrTc (badFieldCon name field_label) `thenNF_Tc_`
- tc_fields field_tys rpats
-
- | otherwise
- = ASSERT( null extras )
- tc_fields field_tys rpats `thenTc` \ (rpats', lie_req1, tvs1, ids1, lie_avail1) ->
-
- tcLookupValue field_label `thenNF_Tc` \ sel_id ->
- tcPat tc_bndr rhs_pat rhs_ty `thenTc` \ (rhs_pat', lie_req2, tvs2, ids2, lie_avail2) ->
+ = tc_fields field_tys rpats `thenTc` \ (rpats', lie_req1, tvs1, ids1, lie_avail1) ->
+
+ (case [ty | (f,ty) <- field_tys, f == field_label] of
+
+ -- No matching field; chances are this field label comes from some
+ -- other record type (or maybe none). As well as reporting an
+ -- error we still want to typecheck the pattern, principally to
+ -- make sure that all the variables it binds are put into the
+ -- environment, else the type checker crashes later:
+ -- f (R { foo = (a,b) }) = a+b
+ -- If foo isn't one of R's fields, we don't want to crash when
+ -- typechecking the "a+b".
+ [] -> addErrTc (badFieldCon name field_label) `thenNF_Tc_`
+ newTyVarTy boxedTypeKind `thenNF_Tc_`
+ returnTc (error "Bogus selector Id", pat_ty)
+
+ -- The normal case, when the field comes from the right constructor
+ (pat_ty : extras) ->
+ ASSERT( null extras )
+ tcLookupValue field_label `thenNF_Tc` \ sel_id ->
+ returnTc (sel_id, pat_ty)
+ ) `thenTc` \ (sel_id, pat_ty) ->
+
+ tcPat tc_bndr rhs_pat pat_ty `thenTc` \ (rhs_pat', lie_req2, tvs2, ids2, lie_avail2) ->
returnTc ((sel_id, rhs_pat', pun_flag) : rpats',
lie_req1 `plusLIE` lie_req2,
tvs1 `unionBags` tvs2,
ids1 `unionBags` ids2,
lie_avail1 `plusLIE` lie_avail2)
- where
- matching_fields = [ty | (f,ty) <- field_tys, f == field_label]
- (rhs_ty : extras) = matching_fields
\end{code}
%************************************************************************
tcPat tc_bndr (LitPatIn lit@(HsFloatPrim _)) pat_ty = tcSimpleLitPat lit floatPrimTy pat_ty
tcPat tc_bndr (LitPatIn lit@(HsDoublePrim _)) pat_ty = tcSimpleLitPat lit doublePrimTy pat_ty
-tcPat tc_bndr (LitPatIn lit@(HsLitLit s)) pat_ty = tcSimpleLitPat lit intTy pat_ty
- -- This one looks weird!
+tcPat tc_bndr (LitPatIn lit@(HsLitLit s)) pat_ty
+ -- cf tcExpr on LitLits
+ = tcLookupClassByKey cCallableClassKey `thenNF_Tc` \ cCallableClass ->
+ newDicts (LitLitOrigin (_UNPK_ s))
+ [mkClassPred cCallableClass [pat_ty]] `thenNF_Tc` \ (dicts, _) ->
+ returnTc (LitPat lit pat_ty, dicts, emptyBag, emptyBag, emptyLIE)
\end{code}
%************************************************************************
tcConstructor pat con_name pat_ty
= -- Check that it's a constructor
tcLookupValue con_name `thenNF_Tc` \ con_id ->
- case isDataConId_maybe con_id of {
+ case isDataConWrapId_maybe con_id of {
Nothing -> failWithTc (badCon con_id);
Just data_con ->
-- Instantiate it
let
- (tvs, theta, ex_tvs, ex_theta, arg_tys, tycon) = dataConSig data_con
+ (tvs, _, ex_tvs, ex_theta, arg_tys, tycon) = dataConSig data_con
-- Ignore the theta; overloaded constructors only
-- behave differently when called, not when used for
-- matching.
in
tcInstTyVars (ex_tvs ++ tvs) `thenNF_Tc` \ (all_tvs', ty_args', tenv) ->
let
- ex_theta' = substTheta tenv ex_theta
+ ex_theta' = substClasses tenv ex_theta
arg_tys' = map (substTy tenv) arg_tys
n_ex_tvs = length ex_tvs
ex_tvs' = take n_ex_tvs all_tvs'
result_ty = mkTyConApp tycon (drop n_ex_tvs ty_args')
in
- newDicts (PatOrigin pat) ex_theta' `thenNF_Tc` \ (lie_avail, dicts) ->
+ newClassDicts (PatOrigin pat) ex_theta' `thenNF_Tc` \ (lie_avail, dicts) ->
-- Check overall type matches
unifyTauTy pat_ty result_ty `thenTc_`
polyPatSig :: TcType -> SDoc
polyPatSig sig_ty
- = hang (ptext SLIT("Polymorphic type signature in pattern"))
+ = hang (ptext SLIT("Illegal polymorphic type signature in pattern:"))
4 (ppr sig_ty)
\end{code}