\section[TcPat]{Typechecking patterns}
\begin{code}
-module TcPat ( tcPat, tcVarPat, badFieldCon, polyPatSig ) where
+module TcPat ( tcPat, tcPatBndr_NoSigs, simpleHsLitTy, badFieldCon, polyPatSig ) where
#include "HsVersions.h"
-import {-# SOURCE #-} TcExpr( tcExpr )
-
-import HsSyn ( InPat(..), OutPat(..), HsLit(..), HsExpr(..), Sig(..) )
+import HsSyn ( InPat(..), OutPat(..), HsLit(..), HsOverLit(..), HsExpr(..) )
import RnHsSyn ( RenamedPat )
import TcHsSyn ( TcPat, TcId )
import TcMonad
-import Inst ( Inst, OverloadedLit(..), InstOrigin(..),
+import Inst ( InstOrigin(..),
emptyLIE, plusLIE, LIE,
- newMethod, newMethodWithGivenTy, 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, mkUserId, idType, isDataConId_maybe )
-import Type ( Type, isTauTy, substTopTy, substTopTheta, mkTyConApp )
+import DataCon ( dataConSig, dataConFieldLabels,
+ dataConSourceArity
+ )
+import Id ( isDataConWrapId_maybe )
+import 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 TysWiredIn ( charTy, stringTy, intTy, integerTy )
+import PrelNames ( eqClassOpKey, geClassOpKey,
+ cCallableClassKey, eqStringIdKey,
+ )
+import BasicTypes ( isBoxed )
import Bag
-import Util ( zipEqual )
import Outputable
\end{code}
%************************************************************************
\begin{code}
-tcVarPat :: (Name -> Maybe TcId) -- Info about signatures; gives the *monomorphic*
- -- Id for variables with a type signature
- -> Name
-
- -> TcType -- Expected type, derived from the context
- -- In the case of a function with a rank-2 signature,
- -- this type might be a forall type.
- -- INVARIANT: if it is, the foralls will always be visible,
- -- not hidden inside a mutable type variable
-
- -> TcM s TcId -- The monomorphic Id; this is put in the pattern itself
-
-tcVarPat sig_fn binder_name pat_ty
- = case sig_fn binder_name of
- Nothing -> newLocalId (getOccName binder_name) pat_ty `thenNF_Tc` \ bndr_id ->
- returnTc bndr_id
-
- Just bndr_id -> tcAddSrcLoc (getSrcLoc binder_name) $
- unifyTauTy (idType bndr_id) pat_ty `thenTc_`
- returnTc bndr_id
+-- This is the right function to pass to tcPat when there are no signatures
+tcPatBndr_NoSigs binder_name pat_ty
+ = -- Need to make a new, monomorphic, Id
+ -- The binder_name is already being used for the polymorphic Id
+ newLocalId (getOccName binder_name) pat_ty loc `thenNF_Tc` \ bndr_id ->
+ returnTc bndr_id
+ where
+ loc = getSrcLoc binder_name
\end{code}
%************************************************************************
\begin{code}
-tcPat :: (Name -> Maybe TcId) -- Info about signatures; gives the *monomorphic*
- -- Id for variables with a type signature
+tcPat :: (Name -> TcType -> TcM s TcId) -- How to construct a suitable (monomorphic)
+ -- Id for variables found in the pattern
+ -- The TcType is the expected type, see note below
-> RenamedPat
- -> TcType -- Expected type; see invariant in tcVarPat
+
+ -> TcType -- Expected type derived from the context
+ -- In the case of a function with a rank-2 signature,
+ -- this type might be a forall type.
+ -- INVARIANT: if it is, the foralls will always be visible,
+ -- not hidden inside a mutable type variable
+
-> TcM s (TcPat,
LIE, -- Required by n+k and literal pats
Bag TcTyVar, -- TyVars bound by the pattern
%************************************************************************
\begin{code}
-tcPat sig_fn (VarPatIn name) pat_ty
- = tcVarPat sig_fn name pat_ty `thenTc` \ bndr_id ->
+tcPat tc_bndr (VarPatIn name) pat_ty
+ = tc_bndr name pat_ty `thenTc` \ bndr_id ->
returnTc (VarPat bndr_id, emptyLIE, emptyBag, unitBag (name, bndr_id), emptyLIE)
-tcPat sig_fn (LazyPatIn pat) pat_ty
- = tcPat sig_fn pat pat_ty `thenTc` \ (pat', lie_req, tvs, ids, lie_avail) ->
+tcPat tc_bndr (LazyPatIn pat) pat_ty
+ = tcPat tc_bndr pat pat_ty `thenTc` \ (pat', lie_req, tvs, ids, lie_avail) ->
returnTc (LazyPat pat', lie_req, tvs, ids, lie_avail)
-tcPat sig_fn pat_in@(AsPatIn name pat) pat_ty
- = tcVarPat sig_fn name pat_ty `thenTc` \ bndr_id ->
- tcPat sig_fn pat pat_ty `thenTc` \ (pat', lie_req, tvs, ids, lie_avail) ->
+tcPat tc_bndr pat_in@(AsPatIn name pat) pat_ty
+ = tc_bndr name pat_ty `thenTc` \ bndr_id ->
+ tcPat tc_bndr pat pat_ty `thenTc` \ (pat', lie_req, tvs, ids, lie_avail) ->
tcAddErrCtxt (patCtxt pat_in) $
returnTc (AsPat bndr_id pat', lie_req,
tvs, (name, bndr_id) `consBag` ids, lie_avail)
-tcPat sig_fn WildPatIn pat_ty
+tcPat tc_bndr WildPatIn pat_ty
= returnTc (WildPat pat_ty, emptyLIE, emptyBag, emptyBag, emptyLIE)
-tcPat sig_fn (NegPatIn pat) pat_ty
- = tcPat sig_fn (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"
-
-tcPat sig_fn (ParPatIn parend_pat) pat_ty
- = tcPat sig_fn parend_pat pat_ty
+tcPat tc_bndr (ParPatIn parend_pat) pat_ty
+ = tcPat tc_bndr parend_pat pat_ty
-tcPat sig_fn (SigPatIn pat sig) pat_ty
- = tcHsType sig `thenTc` \ sig_ty ->
+tcPat tc_bndr (SigPatIn pat sig) pat_ty
+ = tcHsSigType sig `thenTc` \ sig_ty ->
-- Check that the signature isn't a polymorphic one, which
-- we don't permit (at present, anyway)
checkTc (isTauTy sig_ty) (polyPatSig sig_ty) `thenTc_`
unifyTauTy pat_ty sig_ty `thenTc_`
- tcPat sig_fn pat sig_ty
+ tcPat tc_bndr pat sig_ty
\end{code}
%************************************************************************
%************************************************************************
\begin{code}
-tcPat sig_fn pat_in@(ListPatIn pats) pat_ty
+tcPat tc_bndr pat_in@(ListPatIn pats) pat_ty
= tcAddErrCtxt (patCtxt pat_in) $
unifyListTy pat_ty `thenTc` \ elem_ty ->
- tcPats sig_fn pats (repeat elem_ty) `thenTc` \ (pats', lie_req, tvs, ids, lie_avail) ->
+ 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 sig_fn 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 sig_fn 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
%************************************************************************
\begin{code}
-tcPat sig_fn pat@(ConPatIn name arg_pats) pat_ty
- = tcConPat sig_fn pat name arg_pats pat_ty
+tcPat tc_bndr pat@(ConPatIn name arg_pats) pat_ty
+ = tcConPat tc_bndr pat name arg_pats pat_ty
-tcPat sig_fn pat@(ConOpPatIn pat1 op _ pat2) pat_ty
- = tcConPat sig_fn pat op [pat1, pat2] pat_ty
+tcPat tc_bndr pat@(ConOpPatIn pat1 op _ pat2) pat_ty
+ = tcConPat tc_bndr pat op [pat1, pat2] pat_ty
\end{code}
%************************************************************************
\begin{code}
-tcPat sig_fn pat@(RecPatIn name rpats) pat_ty
+tcPat tc_bndr pat@(RecPatIn name rpats) pat_ty
= tcAddErrCtxt (patCtxt pat) $
-- 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
+ -- Don't use 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 sig_fn 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}
%************************************************************************
%* *
-\subsection{Non-overloaded literals}
+\subsection{Literals}
%* *
%************************************************************************
\begin{code}
-tcPat sig_fn (LitPatIn lit@(HsChar _)) pat_ty = tcSimpleLitPat lit charTy pat_ty
-tcPat sig_fn (LitPatIn lit@(HsIntPrim _)) pat_ty = tcSimpleLitPat lit intPrimTy pat_ty
-tcPat sig_fn (LitPatIn lit@(HsCharPrim _)) pat_ty = tcSimpleLitPat lit charPrimTy pat_ty
-tcPat sig_fn (LitPatIn lit@(HsStringPrim _)) pat_ty = tcSimpleLitPat lit addrPrimTy pat_ty
-tcPat sig_fn (LitPatIn lit@(HsFloatPrim _)) pat_ty = tcSimpleLitPat lit floatPrimTy pat_ty
-tcPat sig_fn (LitPatIn lit@(HsDoublePrim _)) pat_ty = tcSimpleLitPat lit doublePrimTy pat_ty
-
-tcPat sig_fn (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 (HsLitLit s pat_ty) pat_ty, dicts, emptyBag, emptyBag, emptyLIE)
+
+tcPat tc_bndr pat@(LitPatIn lit@(HsString _)) pat_ty
+ = unifyTauTy pat_ty stringTy `thenTc_`
+ tcLookupValueByKey eqStringIdKey `thenNF_Tc` \ eq_id ->
+ returnTc (NPat lit stringTy (HsVar eq_id `HsApp` HsLit lit),
+ emptyLIE, emptyBag, emptyBag, emptyLIE)
+
+tcPat tc_bndr (LitPatIn simple_lit) pat_ty
+ = unifyTauTy pat_ty (simpleHsLitTy simple_lit) `thenTc_`
+ returnTc (LitPat simple_lit pat_ty, emptyLIE, emptyBag, emptyBag, emptyLIE)
+
+tcPat tc_bndr pat@(NPatIn over_lit) pat_ty
+ = newOverloadedLit (PatOrigin pat) over_lit pat_ty `thenNF_Tc` \ (over_lit_expr, lie1) ->
+ tcLookupValueByKey eqClassOpKey `thenNF_Tc` \ eq_sel_id ->
+ newMethod origin eq_sel_id [pat_ty] `thenNF_Tc` \ (lie2, eq_id) ->
+
+ returnTc (NPat lit' pat_ty (HsApp (HsVar eq_id) over_lit_expr),
+ lie1 `plusLIE` lie2,
+ emptyBag, emptyBag, emptyLIE)
+ where
+ origin = PatOrigin pat
+ lit' = case over_lit of
+ HsIntegral i _ -> HsInteger i
+ HsFractional f _ -> HsRat f pat_ty
\end{code}
%************************************************************************
%* *
-\subsection{Overloaded patterns: int literals and \tr{n+k} patterns}
+\subsection{n+k patterns}
%* *
%************************************************************************
\begin{code}
-tcPat sig_fn pat@(LitPatIn lit@(HsString str)) pat_ty
- = unifyTauTy pat_ty stringTy `thenTc_`
- tcLookupValueByKey eqClassOpKey `thenNF_Tc` \ sel_id ->
- newMethod (PatOrigin pat) sel_id [stringTy] `thenNF_Tc` \ (lie, eq_id) ->
- let
- comp_op = HsApp (HsVar eq_id) (HsLitOut lit stringTy)
- in
- returnTc (NPat lit stringTy comp_op, lie, emptyBag, emptyBag, emptyLIE)
-
-
-tcPat sig_fn pat@(LitPatIn lit@(HsInt i)) pat_ty
- = tcOverloadedLitPat pat lit (OverloadedIntegral i) pat_ty
-
-tcPat sig_fn pat@(LitPatIn lit@(HsFrac f)) pat_ty
- = tcOverloadedLitPat pat lit (OverloadedFractional f) pat_ty
-
-
-tcPat sig_fn pat@(NPlusKPatIn name lit@(HsInt i)) pat_ty
- = tcVarPat sig_fn name pat_ty `thenTc` \ bndr_id ->
+tcPat tc_bndr pat@(NPlusKPatIn name lit@(HsIntegral i _) minus) pat_ty
+ = tc_bndr name pat_ty `thenTc` \ bndr_id ->
+ tcLookupValue minus `thenNF_Tc` \ minus_sel_id ->
tcLookupValueByKey geClassOpKey `thenNF_Tc` \ ge_sel_id ->
- tcLookupValueByKey minusClassOpKey `thenNF_Tc` \ minus_sel_id ->
-
- newOverloadedLit origin
- (OverloadedIntegral i) pat_ty `thenNF_Tc` \ (over_lit_expr, lie1) ->
-
+ newOverloadedLit origin lit pat_ty `thenNF_Tc` \ (over_lit_expr, lie1) ->
newMethod origin ge_sel_id [pat_ty] `thenNF_Tc` \ (lie2, ge_id) ->
newMethod origin minus_sel_id [pat_ty] `thenNF_Tc` \ (lie3, minus_id) ->
- returnTc (NPlusKPat bndr_id lit pat_ty
+ returnTc (NPlusKPat bndr_id i pat_ty
(SectionR (HsVar ge_id) over_lit_expr)
(SectionR (HsVar minus_id) over_lit_expr),
lie1 `plusLIE` lie2 `plusLIE` lie3,
emptyBag, unitBag (name, bndr_id), emptyLIE)
where
origin = PatOrigin pat
-
-tcPat sig_fn (NPlusKPatIn pat other) pat_ty
- = panic "TcPat:NPlusKPat: not an HsInt literal"
\end{code}
%************************************************************************
Helper functions
\begin{code}
-tcPats :: (Name -> Maybe TcId) -- Info about signatures
- -> [RenamedPat] -> [TcType] -- Excess 'expected types' discarded
+tcPats :: (Name -> TcType -> TcM s TcId) -- How to deal with variables
+ -> [RenamedPat] -> [TcType] -- Excess 'expected types' discarded
-> TcM s ([TcPat],
LIE, -- Required by n+k and literal pats
Bag TcTyVar,
Bag (Name, TcId), -- Ids bound by the pattern
LIE) -- Dicts bound by the pattern
-tcPats sig_fn [] tys = returnTc ([], emptyLIE, emptyBag, emptyBag, emptyLIE)
+tcPats tc_bndr [] tys = returnTc ([], emptyLIE, emptyBag, emptyBag, emptyLIE)
-tcPats sig_fn (ty:tys) (pat:pats)
- = tcPat sig_fn ty pat `thenTc` \ (pat', lie_req1, tvs1, ids1, lie_avail1) ->
- tcPats sig_fn tys pats `thenTc` \ (pats', lie_req2, tvs2, ids2, lie_avail2) ->
+tcPats tc_bndr (ty:tys) (pat:pats)
+ = tcPat tc_bndr ty pat `thenTc` \ (pat', lie_req1, tvs1, ids1, lie_avail1) ->
+ tcPats tc_bndr tys pats `thenTc` \ (pats', lie_req2, tvs2, ids2, lie_avail2) ->
returnTc (pat':pats', lie_req1 `plusLIE` lie_req2,
tvs1 `unionBags` tvs2, ids1 `unionBags` ids2,
------------------------------------------------------
\begin{code}
-tcSimpleLitPat lit lit_ty pat_ty
- = unifyTauTy pat_ty lit_ty `thenTc_`
- returnTc (LitPat lit lit_ty, emptyLIE, emptyBag, emptyBag, emptyLIE)
-
-
-tcOverloadedLitPat pat lit over_lit pat_ty
- = newOverloadedLit (PatOrigin pat) over_lit pat_ty `thenNF_Tc` \ (over_lit_expr, lie1) ->
- tcLookupValueByKey eqClassOpKey `thenNF_Tc` \ eq_sel_id ->
- newMethod origin eq_sel_id [pat_ty] `thenNF_Tc` \ (lie2, eq_id) ->
-
- returnTc (NPat lit pat_ty (HsApp (HsVar eq_id)
- over_lit_expr),
- lie1 `plusLIE` lie2,
- emptyBag, emptyBag, emptyLIE)
- where
- origin = PatOrigin pat
+simpleHsLitTy :: HsLit -> TcType
+simpleHsLitTy (HsCharPrim c) = charPrimTy
+simpleHsLitTy (HsStringPrim s) = addrPrimTy
+simpleHsLitTy (HsInt i) = intTy
+simpleHsLitTy (HsInteger i) = integerTy
+simpleHsLitTy (HsIntPrim i) = intPrimTy
+simpleHsLitTy (HsFloatPrim f) = floatPrimTy
+simpleHsLitTy (HsDoublePrim d) = doublePrimTy
+simpleHsLitTy (HsChar c) = charTy
+simpleHsLitTy (HsString str) = stringTy
\end{code}
+
------------------------------------------------------
\begin{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' = substTopTheta tenv ex_theta
- arg_tys' = map (substTopTy tenv) arg_tys
+ 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_`
------------------------------------------------------
\begin{code}
-tcConPat sig_fn pat con_name arg_pats pat_ty
+tcConPat tc_bndr pat con_name arg_pats pat_ty
= tcAddErrCtxt (patCtxt pat) $
-- Check the constructor itself
(arityErr "Constructor" data_con con_arity no_of_args) `thenTc_`
-- Check arguments
- tcPats sig_fn arg_pats arg_tys' `thenTc` \ (arg_pats', lie_req, tvs, ids, lie_avail2) ->
+ tcPats tc_bndr arg_pats arg_tys' `thenTc` \ (arg_pats', lie_req, tvs, ids, lie_avail2) ->
returnTc (ConPat data_con pat_ty ex_tvs' dicts arg_pats',
lie_req,
patCtxt pat = hang (ptext SLIT("In the pattern:"))
4 (ppr pat)
-recordLabel field_label
- = hang (hcat [ptext SLIT("When matching record field"), ppr field_label])
- 4 (hcat [ptext SLIT("with its immediately enclosing constructor")])
-
-recordRhs field_label pat
- = hang (ptext SLIT("In the record field pattern"))
- 4 (sep [ppr field_label, char '=', ppr pat])
-
badFieldCon :: Name -> Name -> SDoc
badFieldCon con field
= hsep [ptext SLIT("Constructor") <+> quotes (ppr con),
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}
projects / ghc-hetmet.git / blobdiff