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 TcType ( TcType, TcTyVar, tcInstTyVars, newTyVarTy )
import TcMonoType ( tcHsType )
import TcUnify ( unifyTauTy, unifyListTy,
unifyTupleTy, unifyUnboxedTupleTy
import Bag ( Bag )
import CmdLineOpts ( opt_IrrefutableTuples )
-import DataCon ( DataCon, dataConSig, dataConFieldLabels, dataConSourceArity )
+import DataCon ( DataCon, dataConSig, dataConFieldLabels,
+ dataConSourceArity
+ )
import Id ( Id, idType, isDataConId_maybe )
-import Type ( Type, isTauTy, mkTyConApp )
-import Subst ( substTy, substTheta )
+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 Bag
import Util ( zipEqual )
import Outputable
= 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}
%************************************************************************
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_`