\section[TcPat]{Typechecking patterns}
\begin{code}
-module TcPat ( tcPat, tcPatBndr_NoSigs, simpleHsLitTy, badFieldCon, polyPatSig ) where
+module TcPat ( tcPat, tcMonoPatBndr, simpleHsLitTy, badFieldCon, polyPatSig ) where
#include "HsVersions.h"
import TcMonad
import Inst ( InstOrigin(..),
- emptyLIE, plusLIE, LIE,
- newMethod, newOverloadedLit, newDicts, newClassDicts
+ emptyLIE, plusLIE, LIE, mkLIE, unitLIE, instToId,
+ newMethod, newOverloadedLit, newDicts
)
-import Name ( Name, getOccName, getSrcLoc )
+import Id ( mkLocalId )
+import Name ( Name )
import FieldLabel ( fieldLabelName )
-import TcEnv ( tcLookupValue, tcLookupClassByKey,
- tcLookupValueByKey, newLocalId, badCon
- )
-import TcType ( TcType, TcTyVar, tcInstTyVars, newTyVarTy )
-import TcMonoType ( tcHsSigType )
-import TcUnify ( unifyTauTy, unifyListTy, unifyTupleTy )
+import TcEnv ( tcLookupClass, tcLookupDataCon, tcLookupGlobalId, tcLookupId )
+import TcMType ( tcInstTyVars, newTyVarTy, unifyTauTy, unifyListTy, unifyTupleTy )
+import TcType ( isTauTy, mkTyConApp, mkClassPred, liftedTypeKind )
+import TcMonoType ( tcHsSigType, UserTypeCtxt(..) )
import CmdLineOpts ( opt_IrrefutableTuples )
import DataCon ( dataConSig, dataConFieldLabels,
dataConSourceArity
)
-import Id ( isDataConWrapId_maybe )
-import Type ( isTauTy, mkTyConApp, mkClassPred, boxedTypeKind )
-import Subst ( substTy, substClasses )
+import Subst ( substTy, substTheta )
import TysPrim ( charPrimTy, intPrimTy, floatPrimTy,
doublePrimTy, addrPrimTy
)
import TysWiredIn ( charTy, stringTy, intTy, integerTy )
-import PrelNames ( eqClassOpKey, geClassOpKey,
- cCallableClassKey, eqStringIdKey,
- )
+import PrelNames ( eqStringName, eqName, geName, cCallableClassName )
import BasicTypes ( isBoxed )
import Bag
import Outputable
%************************************************************************
\begin{code}
--- 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
+-- This is the right function to pass to tcPat when
+-- we're looking at a lambda-bound pattern,
+-- so there's no polymorphic guy to worry about
+tcMonoPatBndr binder_name pat_ty = returnTc (mkLocalId binder_name pat_ty)
\end{code}
%************************************************************************
\begin{code}
-tcPat :: (Name -> TcType -> TcM s TcId) -- How to construct a suitable (monomorphic)
+tcPat :: (Name -> TcType -> TcM TcId) -- How to construct a suitable (monomorphic)
-- Id for variables found in the pattern
-- The TcType is the expected type, see note below
-> RenamedPat
-- INVARIANT: if it is, the foralls will always be visible,
-- not hidden inside a mutable type variable
- -> TcM s (TcPat,
+ -> TcM (TcPat,
LIE, -- Required by n+k and literal pats
Bag TcTyVar, -- TyVars bound by the pattern
-- These are just the existentially-bound ones.
= tcPat tc_bndr parend_pat pat_ty
tcPat tc_bndr (SigPatIn pat sig) pat_ty
- = tcHsSigType sig `thenTc` \ sig_ty ->
+ = tcHsSigType PatSigCtxt sig `thenTc` \ sig_ty ->
-- Check that the signature isn't a polymorphic one, which
-- we don't permit (at present, anyway)
-- 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_`
+ newTyVarTy liftedTypeKind `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 ->
+ tcLookupGlobalId field_label `thenNF_Tc` \ sel_id ->
returnTc (sel_id, pat_ty)
) `thenTc` \ (sel_id, pat_ty) ->
\begin{code}
tcPat tc_bndr (LitPatIn lit@(HsLitLit s _)) pat_ty
-- cf tcExpr on LitLits
- = tcLookupClassByKey cCallableClassKey `thenNF_Tc` \ cCallableClass ->
+ = tcLookupClass cCallableClassName `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)
+ [mkClassPred cCallableClass [pat_ty]] `thenNF_Tc` \ dicts ->
+ returnTc (LitPat (HsLitLit s pat_ty) pat_ty, mkLIE dicts, emptyBag, emptyBag, emptyLIE)
tcPat tc_bndr pat@(LitPatIn lit@(HsString _)) pat_ty
= unifyTauTy pat_ty stringTy `thenTc_`
- tcLookupValueByKey eqStringIdKey `thenNF_Tc` \ eq_id ->
+ tcLookupGlobalId eqStringName `thenNF_Tc` \ eq_id ->
returnTc (NPat lit stringTy (HsVar eq_id `HsApp` HsLit lit),
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) ->
+ tcLookupGlobalId eqName `thenNF_Tc` \ eq_sel_id ->
+ newMethod origin eq_sel_id [pat_ty] `thenNF_Tc` \ eq ->
- returnTc (NPat lit' pat_ty (HsApp (HsVar eq_id) over_lit_expr),
- lie1 `plusLIE` lie2,
+ returnTc (NPat lit' pat_ty (HsApp (HsVar (instToId eq)) over_lit_expr),
+ lie1 `plusLIE` unitLIE eq,
emptyBag, emptyBag, emptyLIE)
where
origin = PatOrigin pat
lit' = case over_lit of
- HsIntegral i _ -> HsInteger i
+ HsIntegral i _ -> HsInteger i
HsFractional f _ -> HsRat f pat_ty
\end{code}
%************************************************************************
\begin{code}
-tcPat tc_bndr pat@(NPlusKPatIn name lit@(HsIntegral i _) minus) pat_ty
+tcPat tc_bndr pat@(NPlusKPatIn name lit@(HsIntegral i _) minus_name) pat_ty
= tc_bndr name pat_ty `thenTc` \ bndr_id ->
- tcLookupValue minus `thenNF_Tc` \ minus_sel_id ->
- tcLookupValueByKey geClassOpKey `thenNF_Tc` \ ge_sel_id ->
+ -- The '-' part is re-mappable syntax
+ tcLookupId minus_name `thenNF_Tc` \ minus_sel_id ->
+ tcLookupGlobalId geName `thenNF_Tc` \ ge_sel_id ->
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) ->
+ newMethod origin ge_sel_id [pat_ty] `thenNF_Tc` \ ge ->
+ newMethod origin minus_sel_id [pat_ty] `thenNF_Tc` \ minus ->
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,
+ (SectionR (HsVar (instToId ge)) over_lit_expr)
+ (SectionR (HsVar (instToId minus)) over_lit_expr),
+ lie1 `plusLIE` mkLIE [ge,minus],
emptyBag, unitBag (name, bndr_id), emptyLIE)
where
origin = PatOrigin pat
Helper functions
\begin{code}
-tcPats :: (Name -> TcType -> TcM s TcId) -- How to deal with variables
+tcPats :: (Name -> TcType -> TcM TcId) -- How to deal with variables
-> [RenamedPat] -> [TcType] -- Excess 'expected types' discarded
- -> TcM s ([TcPat],
+ -> TcM ([TcPat],
LIE, -- Required by n+k and literal pats
Bag TcTyVar,
Bag (Name, TcId), -- Ids bound by the pattern
\begin{code}
tcConstructor pat con_name pat_ty
= -- Check that it's a constructor
- tcLookupValue con_name `thenNF_Tc` \ con_id ->
- case isDataConWrapId_maybe con_id of {
- Nothing -> failWithTc (badCon con_id);
- Just data_con ->
+ tcLookupDataCon con_name `thenNF_Tc` \ data_con ->
-- Instantiate it
let
in
tcInstTyVars (ex_tvs ++ tvs) `thenNF_Tc` \ (all_tvs', ty_args', tenv) ->
let
- ex_theta' = substClasses tenv ex_theta
+ ex_theta' = substTheta 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
- newClassDicts (PatOrigin pat) ex_theta' `thenNF_Tc` \ (lie_avail, dicts) ->
+ newDicts (PatOrigin pat) ex_theta' `thenNF_Tc` \ dicts ->
-- Check overall type matches
unifyTauTy pat_ty result_ty `thenTc_`
- returnTc (data_con, ex_tvs', dicts, lie_avail, arg_tys')
- }
+ returnTc (data_con, ex_tvs', map instToId dicts, mkLIE dicts, arg_tys')
\end{code}
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