\section[TcExpr]{Typecheck an expression}
\begin{code}
-module TcExpr ( tcExpr, tcMonoExpr, tcId ) where
+module TcExpr ( tcExpr, tcExpr_id, tcMonoExpr ) where
#include "HsVersions.h"
-import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
- HsMatchContext(..), HsDoContext(..),
- mkMonoBind
+#ifdef GHCI /* Only if bootstrapped */
+import {-# SOURCE #-} TcSplice( tcSpliceExpr, tcBracket )
+import HsSyn ( HsReify(..), ReifyFlavour(..) )
+import TcType ( isTauTy )
+import TcEnv ( bracketOK, tcMetaTy, tcLookupGlobal,
+ wellStaged, metaLevel )
+import TcSimplify ( tcSimplifyBracket )
+import Name ( isExternalName )
+import qualified DsMeta
+#endif
+
+import HsSyn ( HsExpr(..), HsLit(..), ArithSeqInfo(..),
+ mkMonoBind, recBindFields
)
import RnHsSyn ( RenamedHsExpr, RenamedRecordBinds )
-import TcHsSyn ( TcExpr, TcRecordBinds, simpleHsLitTy, mkHsDictApp, mkHsTyApp )
-
-import TcMonad
+import TcHsSyn ( TcExpr, TcRecordBinds, hsLitType, mkHsDictApp, mkHsTyApp, mkHsLet )
+import TcRnMonad
import TcUnify ( tcSubExp, tcGen, (<$>),
unifyTauTy, unifyFunTy, unifyListTy, unifyPArrTy,
unifyTupleTy )
import BasicTypes ( RecFlag(..), isMarkedStrict )
import Inst ( InstOrigin(..),
- LIE, mkLIE, emptyLIE, unitLIE, plusLIE, plusLIEs,
newOverloadedLit, newMethodFromName, newIPDict,
- newDicts, newMethodWithGivenTy,
+ newDicts, newMethodWithGivenTy,
instToId, tcInstCall, tcInstDataCon
)
import TcBinds ( tcBindsAndThen )
-import TcEnv ( tcLookupClass, tcLookupGlobalId, tcLookupGlobal_maybe,
+import TcEnv ( tcLookupClass, tcLookupGlobal_maybe, tcLookupIdLvl,
tcLookupTyCon, tcLookupDataCon, tcLookupId
)
-import TcMatches ( tcMatchesCase, tcMatchLambda, tcStmts )
+import TcMatches ( tcMatchesCase, tcMatchLambda, tcDoStmts )
import TcMonoType ( tcHsSigType, UserTypeCtxt(..) )
import TcPat ( badFieldCon )
import TcSimplify ( tcSimplifyIPs )
newTyVarTy, newTyVarTys, zonkTcType, readHoleResult )
import TcType ( TcType, TcSigmaType, TcRhoType, TyVarDetails(VanillaTv),
tcSplitFunTys, tcSplitTyConApp, mkTyVarTys,
- isSigmaTy, mkFunTy, mkAppTy, mkTyConTy, mkFunTys,
+ isSigmaTy, mkFunTy, mkFunTys,
mkTyConApp, mkClassPred, tcFunArgTy,
tyVarsOfTypes, isLinearPred,
- liftedTypeKind, openTypeKind, mkArrowKind,
+ liftedTypeKind, openTypeKind,
tcSplitSigmaTy, tcTyConAppTyCon,
tidyOpenType
)
import FieldLabel ( FieldLabel, fieldLabelName, fieldLabelType, fieldLabelTyCon )
-import Id ( idType, recordSelectorFieldLabel, isRecordSelector, isDataConWrapId_maybe )
-import DataCon ( dataConFieldLabels, dataConSig,
- dataConStrictMarks
- )
+import Id ( Id, idType, recordSelectorFieldLabel, isRecordSelector, isDataConWrapId_maybe )
+import DataCon ( DataCon, dataConFieldLabels, dataConSig, dataConStrictMarks )
import Name ( Name )
import TyCon ( TyCon, tyConTyVars, tyConTheta, isAlgTyCon, tyConDataCons )
import Subst ( mkTopTyVarSubst, substTheta, substTy )
import VarSet ( emptyVarSet, elemVarSet )
-import TysWiredIn ( boolTy, mkListTy, mkPArrTy, listTyCon, parrTyCon )
-import PrelNames ( cCallableClassName,
- cReturnableClassName,
+import TysWiredIn ( boolTy )
+import PrelNames ( cCallableClassName, cReturnableClassName,
enumFromName, enumFromThenName,
enumFromToName, enumFromThenToName,
enumFromToPName, enumFromThenToPName,
- thenMName, bindMName, failMName, returnMName, ioTyConName
+ ioTyConName
)
import ListSetOps ( minusList )
import CmdLineOpts
\begin{code}
tcExpr :: RenamedHsExpr -- Expession to type check
-> TcSigmaType -- Expected type (could be a polytpye)
- -> TcM (TcExpr, LIE) -- Generalised expr with expected type, and LIE
+ -> TcM TcExpr -- Generalised expr with expected type
tcExpr expr expected_ty
- = traceTc (text "tcExpr" <+> (ppr expected_ty $$ ppr expr)) `thenNF_Tc_`
+ = traceTc (text "tcExpr" <+> (ppr expected_ty $$ ppr expr)) `thenM_`
tc_expr' expr expected_ty
tc_expr' expr expected_ty
| otherwise
= tcGen expected_ty emptyVarSet (
tcMonoExpr expr
- ) `thenTc` \ (gen_fn, expr', lie) ->
- returnTc (gen_fn <$> expr', lie)
+ ) `thenM` \ (gen_fn, expr') ->
+ returnM (gen_fn <$> expr')
\end{code}
-> TcRhoType -- Expected type (could be a type variable)
-- Definitely no foralls at the top
-- Can be a 'hole'.
- -> TcM (TcExpr, LIE)
+ -> TcM TcExpr
tcMonoExpr (HsVar name) res_ty
- = tcId name `thenNF_Tc` \ (expr', lie1, id_ty) ->
- tcSubExp res_ty id_ty `thenTc` \ (co_fn, lie2) ->
- returnTc (co_fn <$> expr', lie1 `plusLIE` lie2)
+ = tcId name `thenM` \ (expr', id_ty) ->
+ tcSubExp res_ty id_ty `thenM` \ co_fn ->
+ returnM (co_fn <$> expr')
tcMonoExpr (HsIPVar ip) res_ty
= -- Implicit parameters must have a *tau-type* not a
-- type scheme. We enforce this by creating a fresh
-- type variable as its type. (Because res_ty may not
-- be a tau-type.)
- newTyVarTy openTypeKind `thenNF_Tc` \ ip_ty ->
- newIPDict (IPOcc ip) ip ip_ty `thenNF_Tc` \ (ip', inst) ->
- tcSubExp res_ty ip_ty `thenTc` \ (co_fn, lie) ->
- returnNF_Tc (co_fn <$> HsIPVar ip', lie `plusLIE` unitLIE inst)
+ newTyVarTy openTypeKind `thenM` \ ip_ty ->
+ newIPDict (IPOcc ip) ip ip_ty `thenM` \ (ip', inst) ->
+ extendLIE inst `thenM_`
+ tcSubExp res_ty ip_ty `thenM` \ co_fn ->
+ returnM (co_fn <$> HsIPVar ip')
\end{code}
\begin{code}
tcMonoExpr in_expr@(ExprWithTySig expr poly_ty) res_ty
- = tcHsSigType ExprSigCtxt poly_ty `thenTc` \ sig_tc_ty ->
- tcExpr expr sig_tc_ty `thenTc` \ (expr', lie1) ->
+ = addErrCtxt (exprSigCtxt in_expr) $
+ tcHsSigType ExprSigCtxt poly_ty `thenM` \ sig_tc_ty ->
+ tcExpr expr sig_tc_ty `thenM` \ expr' ->
-- Must instantiate the outer for-alls of sig_tc_ty
-- else we risk instantiating a ? res_ty to a forall-type
-- which breaks the invariant that tcMonoExpr only returns phi-types
- tcAddErrCtxt (exprSigCtxt in_expr) $
- tcInstCall SignatureOrigin sig_tc_ty `thenNF_Tc` \ (inst_fn, lie2, inst_sig_ty) ->
- tcSubExp res_ty inst_sig_ty `thenTc` \ (co_fn, lie3) ->
+ tcInstCall SignatureOrigin sig_tc_ty `thenM` \ (inst_fn, inst_sig_ty) ->
+ tcSubExp res_ty inst_sig_ty `thenM` \ co_fn ->
- returnTc (co_fn <$> inst_fn expr', lie1 `plusLIE` lie2 `plusLIE` lie3)
+ returnM (co_fn <$> inst_fn expr')
tcMonoExpr (HsType ty) res_ty
= failWithTc (text "Can't handle type argument:" <+> ppr ty)
%************************************************************************
\begin{code}
-tcMonoExpr (HsLit lit) res_ty = tcLit lit res_ty
-tcMonoExpr (HsOverLit lit) res_ty = newOverloadedLit (LiteralOrigin lit) lit res_ty
-tcMonoExpr (HsPar expr) res_ty = tcMonoExpr expr res_ty
+tcMonoExpr (HsLit lit) res_ty = tcLit lit res_ty
+tcMonoExpr (HsOverLit lit) res_ty = newOverloadedLit (LiteralOrigin lit) lit res_ty
+tcMonoExpr (HsPar expr) res_ty = tcMonoExpr expr res_ty `thenM` \ expr' ->
+ returnM (HsPar expr')
+tcMonoExpr (HsSCC lbl expr) res_ty = tcMonoExpr expr res_ty `thenM` \ expr' ->
+ returnM (HsSCC lbl expr')
+
tcMonoExpr (NegApp expr neg_name) res_ty
= tcMonoExpr (HsApp (HsVar neg_name) expr) res_ty
+ -- ToDo: use tcSyntaxName
tcMonoExpr (HsLam match) res_ty
- = tcMatchLambda match res_ty `thenTc` \ (match',lie) ->
- returnTc (HsLam match', lie)
+ = tcMatchLambda match res_ty `thenM` \ match' ->
+ returnM (HsLam match')
tcMonoExpr (HsApp e1 e2) res_ty
= tcApp e1 [e2] res_ty
-- op e
tcMonoExpr in_expr@(SectionL arg1 op) res_ty
- = tcExpr_id op `thenTc` \ (op', lie1, op_ty) ->
- split_fun_ty op_ty 2 {- two args -} `thenTc` \ ([arg1_ty, arg2_ty], op_res_ty) ->
- tcArg op (arg1, arg1_ty, 1) `thenTc` \ (arg1',lie2) ->
- tcAddErrCtxt (exprCtxt in_expr) $
- tcSubExp res_ty (mkFunTy arg2_ty op_res_ty) `thenTc` \ (co_fn, lie3) ->
- returnTc (co_fn <$> SectionL arg1' op', lie1 `plusLIE` lie2 `plusLIE` lie3)
+ = tcExpr_id op `thenM` \ (op', op_ty) ->
+ split_fun_ty op_ty 2 {- two args -} `thenM` \ ([arg1_ty, arg2_ty], op_res_ty) ->
+ tcArg op (arg1, arg1_ty, 1) `thenM` \ arg1' ->
+ addErrCtxt (exprCtxt in_expr) $
+ tcSubExp res_ty (mkFunTy arg2_ty op_res_ty) `thenM` \ co_fn ->
+ returnM (co_fn <$> SectionL arg1' op')
-- Right sections, equivalent to \ x -> x op expr, or
-- \ x -> op x expr
tcMonoExpr in_expr@(SectionR op arg2) res_ty
- = tcExpr_id op `thenTc` \ (op', lie1, op_ty) ->
- split_fun_ty op_ty 2 {- two args -} `thenTc` \ ([arg1_ty, arg2_ty], op_res_ty) ->
- tcArg op (arg2, arg2_ty, 2) `thenTc` \ (arg2',lie2) ->
- tcAddErrCtxt (exprCtxt in_expr) $
- tcSubExp res_ty (mkFunTy arg1_ty op_res_ty) `thenTc` \ (co_fn, lie3) ->
- returnTc (co_fn <$> SectionR op' arg2', lie1 `plusLIE` lie2 `plusLIE` lie3)
+ = tcExpr_id op `thenM` \ (op', op_ty) ->
+ split_fun_ty op_ty 2 {- two args -} `thenM` \ ([arg1_ty, arg2_ty], op_res_ty) ->
+ tcArg op (arg2, arg2_ty, 2) `thenM` \ arg2' ->
+ addErrCtxt (exprCtxt in_expr) $
+ tcSubExp res_ty (mkFunTy arg1_ty op_res_ty) `thenM` \ co_fn ->
+ returnM (co_fn <$> SectionR op' arg2')
-- equivalent to (op e1) e2:
tcMonoExpr in_expr@(OpApp arg1 op fix arg2) res_ty
- = tcExpr_id op `thenTc` \ (op', lie1, op_ty) ->
- split_fun_ty op_ty 2 {- two args -} `thenTc` \ ([arg1_ty, arg2_ty], op_res_ty) ->
- tcArg op (arg1, arg1_ty, 1) `thenTc` \ (arg1',lie2a) ->
- tcArg op (arg2, arg2_ty, 2) `thenTc` \ (arg2',lie2b) ->
- tcAddErrCtxt (exprCtxt in_expr) $
- tcSubExp res_ty op_res_ty `thenTc` \ (co_fn, lie3) ->
- returnTc (OpApp arg1' op' fix arg2',
- lie1 `plusLIE` lie2a `plusLIE` lie2b `plusLIE` lie3)
+ = tcExpr_id op `thenM` \ (op', op_ty) ->
+ split_fun_ty op_ty 2 {- two args -} `thenM` \ ([arg1_ty, arg2_ty], op_res_ty) ->
+ tcArg op (arg1, arg1_ty, 1) `thenM` \ arg1' ->
+ tcArg op (arg2, arg2_ty, 2) `thenM` \ arg2' ->
+ addErrCtxt (exprCtxt in_expr) $
+ tcSubExp res_ty op_res_ty `thenM` \ co_fn ->
+ returnM (OpApp arg1' op' fix arg2')
\end{code}
-The interesting thing about @ccall@ is that it is just a template
-which we instantiate by filling in details about the types of its
-argument and result (ie minimal typechecking is performed). So, the
-basic story is that we allocate a load of type variables (to hold the
-arg/result types); unify them with the args/result; and store them for
-later use.
-
\begin{code}
-tcMonoExpr e0@(HsCCall lbl args may_gc is_casm ignored_fake_result_ty) res_ty
-
- = getDOptsTc `thenNF_Tc` \ dflags ->
-
- checkTc (not (is_casm && dopt_HscLang dflags /= HscC))
- (vcat [text "_casm_ is only supported when compiling via C (-fvia-C).",
- text "Either compile with -fvia-C, or, better, rewrite your code",
- text "to use the foreign function interface. _casm_s are deprecated",
- text "and support for them may one day disappear."])
- `thenTc_`
-
- -- Get the callable and returnable classes.
- tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass ->
- tcLookupClass cReturnableClassName `thenNF_Tc` \ cReturnableClass ->
- tcLookupTyCon ioTyConName `thenNF_Tc` \ ioTyCon ->
- let
- new_arg_dict (arg, arg_ty)
- = newDicts (CCallOrigin (unpackFS lbl) (Just arg))
- [mkClassPred cCallableClass [arg_ty]] `thenNF_Tc` \ arg_dicts ->
- returnNF_Tc arg_dicts -- Actually a singleton bag
-
- result_origin = CCallOrigin (unpackFS lbl) Nothing {- Not an arg -}
- in
-
- -- Arguments
- let tv_idxs | null args = []
- | otherwise = [1..length args]
- in
- newTyVarTys (length tv_idxs) openTypeKind `thenNF_Tc` \ arg_tys ->
- tcMonoExprs args arg_tys `thenTc` \ (args', args_lie) ->
-
- -- The argument types can be unlifted or lifted; the result
- -- type must, however, be lifted since it's an argument to the IO
- -- type constructor.
- newTyVarTy liftedTypeKind `thenNF_Tc` \ result_ty ->
- let
- io_result_ty = mkTyConApp ioTyCon [result_ty]
- in
- unifyTauTy res_ty io_result_ty `thenTc_`
-
- -- Construct the extra insts, which encode the
- -- constraints on the argument and result types.
- mapNF_Tc new_arg_dict (zipEqual "tcMonoExpr:CCall" args arg_tys) `thenNF_Tc` \ ccarg_dicts_s ->
- newDicts result_origin [mkClassPred cReturnableClass [result_ty]] `thenNF_Tc` \ ccres_dict ->
- returnTc (HsCCall lbl args' may_gc is_casm io_result_ty,
- mkLIE (ccres_dict ++ concat ccarg_dicts_s) `plusLIE` args_lie)
-\end{code}
-
-\begin{code}
-tcMonoExpr (HsSCC lbl expr) res_ty
- = tcMonoExpr expr res_ty `thenTc` \ (expr', lie) ->
- returnTc (HsSCC lbl expr', lie)
-
tcMonoExpr (HsLet binds expr) res_ty
= tcBindsAndThen
combiner
binds -- Bindings to check
- tc_expr `thenTc` \ (expr', lie) ->
- returnTc (expr', lie)
+ (tcMonoExpr expr res_ty)
where
- tc_expr = tcMonoExpr expr res_ty `thenTc` \ (expr', lie) ->
- returnTc (expr', lie)
combiner is_rec bind expr = HsLet (mkMonoBind bind [] is_rec) expr
tcMonoExpr in_expr@(HsCase scrut matches src_loc) res_ty
- = tcAddSrcLoc src_loc $
- tcAddErrCtxt (caseCtxt in_expr) $
+ = addSrcLoc src_loc $
+ addErrCtxt (caseCtxt in_expr) $
-- Typecheck the case alternatives first.
-- The case patterns tend to give good type info to use
-- claimed by the pattern signatures. But if we typechecked the
-- match with x in scope and x's type as the expected type, we'd be hosed.
- tcMatchesCase matches res_ty `thenTc` \ (scrut_ty, matches', lie2) ->
+ tcMatchesCase matches res_ty `thenM` \ (scrut_ty, matches') ->
- tcAddErrCtxt (caseScrutCtxt scrut) (
+ addErrCtxt (caseScrutCtxt scrut) (
tcMonoExpr scrut scrut_ty
- ) `thenTc` \ (scrut',lie1) ->
+ ) `thenM` \ scrut' ->
- returnTc (HsCase scrut' matches' src_loc, plusLIE lie1 lie2)
+ returnM (HsCase scrut' matches' src_loc)
tcMonoExpr (HsIf pred b1 b2 src_loc) res_ty
- = tcAddSrcLoc src_loc $
- tcAddErrCtxt (predCtxt pred) (
- tcMonoExpr pred boolTy ) `thenTc` \ (pred',lie1) ->
+ = addSrcLoc src_loc $
+ addErrCtxt (predCtxt pred) (
+ tcMonoExpr pred boolTy ) `thenM` \ pred' ->
- zapToType res_ty `thenTc` \ res_ty' ->
+ zapToType res_ty `thenM` \ res_ty' ->
-- C.f. the call to zapToType in TcMatches.tcMatches
- tcMonoExpr b1 res_ty' `thenTc` \ (b1',lie2) ->
- tcMonoExpr b2 res_ty' `thenTc` \ (b2',lie3) ->
- returnTc (HsIf pred' b1' b2' src_loc, plusLIE lie1 (plusLIE lie2 lie3))
-\end{code}
+ tcMonoExpr b1 res_ty' `thenM` \ b1' ->
+ tcMonoExpr b2 res_ty' `thenM` \ b2' ->
+ returnM (HsIf pred' b1' b2' src_loc)
-\begin{code}
-tcMonoExpr expr@(HsDo do_or_lc stmts src_loc) res_ty
- = tcDoStmts do_or_lc stmts src_loc res_ty
-\end{code}
+tcMonoExpr (HsDo do_or_lc stmts method_names _ src_loc) res_ty
+ = addSrcLoc src_loc $
+ tcDoStmts do_or_lc stmts method_names res_ty `thenM` \ (binds, stmts', methods') ->
+ returnM (mkHsLet binds (HsDo do_or_lc stmts' methods' res_ty src_loc))
-\begin{code}
tcMonoExpr in_expr@(ExplicitList _ exprs) res_ty -- Non-empty list
- = unifyListTy res_ty `thenTc` \ elt_ty ->
- mapAndUnzipTc (tc_elt elt_ty) exprs `thenTc` \ (exprs', lies) ->
- returnTc (ExplicitList elt_ty exprs', plusLIEs lies)
+ = unifyListTy res_ty `thenM` \ elt_ty ->
+ mappM (tc_elt elt_ty) exprs `thenM` \ exprs' ->
+ returnM (ExplicitList elt_ty exprs')
where
tc_elt elt_ty expr
- = tcAddErrCtxt (listCtxt expr) $
+ = addErrCtxt (listCtxt expr) $
tcMonoExpr expr elt_ty
tcMonoExpr in_expr@(ExplicitPArr _ exprs) res_ty -- maybe empty
- = unifyPArrTy res_ty `thenTc` \ elt_ty ->
- mapAndUnzipTc (tc_elt elt_ty) exprs `thenTc` \ (exprs', lies) ->
- returnTc (ExplicitPArr elt_ty exprs', plusLIEs lies)
+ = unifyPArrTy res_ty `thenM` \ elt_ty ->
+ mappM (tc_elt elt_ty) exprs `thenM` \ exprs' ->
+ returnM (ExplicitPArr elt_ty exprs')
where
tc_elt elt_ty expr
- = tcAddErrCtxt (parrCtxt expr) $
+ = addErrCtxt (parrCtxt expr) $
tcMonoExpr expr elt_ty
tcMonoExpr (ExplicitTuple exprs boxity) res_ty
- = unifyTupleTy boxity (length exprs) res_ty `thenTc` \ arg_tys ->
- mapAndUnzipTc (\ (expr, arg_ty) -> tcMonoExpr expr arg_ty)
- (exprs `zip` arg_tys) -- we know they're of equal length.
- `thenTc` \ (exprs', lies) ->
- returnTc (ExplicitTuple exprs' boxity, plusLIEs lies)
+ = unifyTupleTy boxity (length exprs) res_ty `thenM` \ arg_tys ->
+ tcMonoExprs exprs arg_tys `thenM` \ exprs' ->
+ returnM (ExplicitTuple exprs' boxity)
+\end{code}
+
+%************************************************************************
+%* *
+ Foreign calls
+%* *
+%************************************************************************
+
+The interesting thing about @ccall@ is that it is just a template
+which we instantiate by filling in details about the types of its
+argument and result (ie minimal typechecking is performed). So, the
+basic story is that we allocate a load of type variables (to hold the
+arg/result types); unify them with the args/result; and store them for
+later use.
+
+\begin{code}
+tcMonoExpr e0@(HsCCall lbl args may_gc is_casm ignored_fake_result_ty) res_ty
+
+ = getDOpts `thenM` \ dflags ->
+
+ checkTc (not (is_casm && dopt_HscLang dflags /= HscC))
+ (vcat [text "_casm_ is only supported when compiling via C (-fvia-C).",
+ text "Either compile with -fvia-C, or, better, rewrite your code",
+ text "to use the foreign function interface. _casm_s are deprecated",
+ text "and support for them may one day disappear."])
+ `thenM_`
+
+ -- Get the callable and returnable classes.
+ tcLookupClass cCallableClassName `thenM` \ cCallableClass ->
+ tcLookupClass cReturnableClassName `thenM` \ cReturnableClass ->
+ tcLookupTyCon ioTyConName `thenM` \ ioTyCon ->
+ let
+ new_arg_dict (arg, arg_ty)
+ = newDicts (CCallOrigin (unpackFS lbl) (Just arg))
+ [mkClassPred cCallableClass [arg_ty]] `thenM` \ arg_dicts ->
+ returnM arg_dicts -- Actually a singleton bag
+
+ result_origin = CCallOrigin (unpackFS lbl) Nothing {- Not an arg -}
+ in
+
+ -- Arguments
+ let tv_idxs | null args = []
+ | otherwise = [1..length args]
+ in
+ newTyVarTys (length tv_idxs) openTypeKind `thenM` \ arg_tys ->
+ tcMonoExprs args arg_tys `thenM` \ args' ->
+
+ -- The argument types can be unlifted or lifted; the result
+ -- type must, however, be lifted since it's an argument to the IO
+ -- type constructor.
+ newTyVarTy liftedTypeKind `thenM` \ result_ty ->
+ let
+ io_result_ty = mkTyConApp ioTyCon [result_ty]
+ in
+ unifyTauTy res_ty io_result_ty `thenM_`
+
+ -- Construct the extra insts, which encode the
+ -- constraints on the argument and result types.
+ mappM new_arg_dict (zipEqual "tcMonoExpr:CCall" args arg_tys) `thenM` \ ccarg_dicts_s ->
+ newDicts result_origin [mkClassPred cReturnableClass [result_ty]] `thenM` \ ccres_dict ->
+ extendLIEs (ccres_dict ++ concat ccarg_dicts_s) `thenM_`
+ returnM (HsCCall lbl args' may_gc is_casm io_result_ty)
+\end{code}
+
+
+%************************************************************************
+%* *
+ Record construction and update
+%* *
+%************************************************************************
+
+\begin{code}
tcMonoExpr expr@(RecordCon con_name rbinds) res_ty
- = tcAddErrCtxt (recordConCtxt expr) $
- tcId con_name `thenNF_Tc` \ (con_expr, con_lie, con_tau) ->
+ = addErrCtxt (recordConCtxt expr) $
+ tcId con_name `thenM` \ (con_expr, con_tau) ->
let
(_, record_ty) = tcSplitFunTys con_tau
(tycon, ty_args) = tcSplitTyConApp record_ty
in
ASSERT( isAlgTyCon tycon )
- unifyTauTy res_ty record_ty `thenTc_`
+ unifyTauTy res_ty record_ty `thenM_`
-- Check that the record bindings match the constructor
-- con_name is syntactically constrained to be a data constructor
- tcLookupDataCon con_name `thenTc` \ data_con ->
+ tcLookupDataCon con_name `thenM` \ data_con ->
let
bad_fields = badFields rbinds data_con
in
if notNull bad_fields then
- mapNF_Tc (addErrTc . badFieldCon con_name) bad_fields `thenNF_Tc_`
- failTc -- Fail now, because tcRecordBinds will crash on a bad field
+ mappM (addErrTc . badFieldCon data_con) bad_fields `thenM_`
+ failM -- Fail now, because tcRecordBinds will crash on a bad field
else
-- Typecheck the record bindings
- tcRecordBinds tycon ty_args rbinds `thenTc` \ (rbinds', rbinds_lie) ->
+ tcRecordBinds tycon ty_args rbinds `thenM` \ rbinds' ->
- let
- (missing_s_fields, missing_fields) = missingFields rbinds data_con
- in
- checkTcM (null missing_s_fields)
- (mapNF_Tc (addErrTc . missingStrictFieldCon con_name) missing_s_fields `thenNF_Tc_`
- returnNF_Tc ()) `thenNF_Tc_`
- doptsTc Opt_WarnMissingFields `thenNF_Tc` \ warn ->
- checkTcM (not (warn && notNull missing_fields))
- (mapNF_Tc ((warnTc True) . missingFieldCon con_name) missing_fields `thenNF_Tc_`
- returnNF_Tc ()) `thenNF_Tc_`
+ -- Check for missing fields
+ checkMissingFields data_con rbinds `thenM_`
- returnTc (RecordConOut data_con con_expr rbinds', con_lie `plusLIE` rbinds_lie)
+ returnM (RecordConOut data_con con_expr rbinds')
-- The main complication with RecordUpd is that we need to explicitly
-- handle the *non-updated* fields. Consider:
-- All this is done in STEP 4 below.
tcMonoExpr expr@(RecordUpd record_expr rbinds) res_ty
- = tcAddErrCtxt (recordUpdCtxt expr) $
+ = addErrCtxt (recordUpdCtxt expr) $
-- STEP 0
-- Check that the field names are really field names
ASSERT( notNull rbinds )
let
- field_names = [field_name | (field_name, _, _) <- rbinds]
+ field_names = recBindFields rbinds
in
- mapNF_Tc tcLookupGlobal_maybe field_names `thenNF_Tc` \ maybe_sel_ids ->
+ mappM tcLookupGlobal_maybe field_names `thenM` \ maybe_sel_ids ->
let
bad_guys = [ addErrTc (notSelector field_name)
| (field_name, maybe_sel_id) <- field_names `zip` maybe_sel_ids,
other -> True
]
in
- checkTcM (null bad_guys) (listNF_Tc bad_guys `thenNF_Tc_` failTc) `thenTc_`
+ checkM (null bad_guys) (sequenceM bad_guys `thenM_` failM) `thenM_`
-- STEP 1
-- Figure out the tycon and data cons from the first field name
data_cons = tyConDataCons tycon
tycon_tyvars = tyConTyVars tycon -- The data cons use the same type vars
in
- tcInstTyVars VanillaTv tycon_tyvars `thenNF_Tc` \ (_, result_inst_tys, inst_env) ->
+ tcInstTyVars VanillaTv tycon_tyvars `thenM` \ (_, result_inst_tys, inst_env) ->
-- STEP 2
-- Check that at least one constructor has all the named fields
-- i.e. has an empty set of bad fields returned by badFields
checkTc (any (null . badFields rbinds) data_cons)
- (badFieldsUpd rbinds) `thenTc_`
+ (badFieldsUpd rbinds) `thenM_`
-- STEP 3
-- Typecheck the update bindings.
let
result_record_ty = mkTyConApp tycon result_inst_tys
in
- unifyTauTy res_ty result_record_ty `thenTc_`
- tcRecordBinds tycon result_inst_tys rbinds `thenTc` \ (rbinds', rbinds_lie) ->
+ unifyTauTy res_ty result_record_ty `thenM_`
+ tcRecordBinds tycon result_inst_tys rbinds `thenM` \ rbinds' ->
-- STEP 4
-- Use the un-updated fields to find a vector of booleans saying
-- WARNING: this code assumes that all data_cons in a common tycon
-- have FieldLabels abstracted over the same tyvars.
let
- upd_field_lbls = [recordSelectorFieldLabel sel_id | (sel_id, _, _) <- rbinds']
+ upd_field_lbls = map recordSelectorFieldLabel (recBindFields rbinds')
con_field_lbls_s = map dataConFieldLabels data_cons
-- A constructor is only relevant to this process if
common_tyvars = tyVarsOfTypes (map fieldLabelType non_upd_field_lbls)
mk_inst_ty (tyvar, result_inst_ty)
- | tyvar `elemVarSet` common_tyvars = returnNF_Tc result_inst_ty -- Same as result type
+ | tyvar `elemVarSet` common_tyvars = returnM result_inst_ty -- Same as result type
| otherwise = newTyVarTy liftedTypeKind -- Fresh type
in
- mapNF_Tc mk_inst_ty (zip tycon_tyvars result_inst_tys) `thenNF_Tc` \ inst_tys ->
+ mappM mk_inst_ty (zip tycon_tyvars result_inst_tys) `thenM` \ inst_tys ->
-- STEP 5
-- Typecheck the expression to be updated
let
record_ty = mkTyConApp tycon inst_tys
in
- tcMonoExpr record_expr record_ty `thenTc` \ (record_expr', record_lie) ->
+ tcMonoExpr record_expr record_ty `thenM` \ record_expr' ->
-- STEP 6
-- Figure out the LIE we need. We have to generate some
let
theta' = substTheta inst_env (tyConTheta tycon)
in
- newDicts RecordUpdOrigin theta' `thenNF_Tc` \ dicts ->
+ newDicts RecordUpdOrigin theta' `thenM` \ dicts ->
+ extendLIEs dicts `thenM_`
-- Phew!
- returnTc (RecordUpdOut record_expr' record_ty result_record_ty rbinds',
- mkLIE dicts `plusLIE` record_lie `plusLIE` rbinds_lie)
+ returnM (RecordUpdOut record_expr' record_ty result_record_ty rbinds')
+\end{code}
+
+%************************************************************************
+%* *
+ Arithmetic sequences e.g. [a,b..]
+ and their parallel-array counterparts e.g. [: a,b.. :]
+
+%* *
+%************************************************************************
+
+\begin{code}
tcMonoExpr (ArithSeqIn seq@(From expr)) res_ty
- = unifyListTy res_ty `thenTc` \ elt_ty ->
- tcMonoExpr expr elt_ty `thenTc` \ (expr', lie1) ->
+ = unifyListTy res_ty `thenM` \ elt_ty ->
+ tcMonoExpr expr elt_ty `thenM` \ expr' ->
newMethodFromName (ArithSeqOrigin seq)
- elt_ty enumFromName `thenNF_Tc` \ enum_from ->
+ elt_ty enumFromName `thenM` \ enum_from ->
- returnTc (ArithSeqOut (HsVar (instToId enum_from)) (From expr'),
- lie1 `plusLIE` unitLIE enum_from)
+ returnM (ArithSeqOut (HsVar enum_from) (From expr'))
tcMonoExpr in_expr@(ArithSeqIn seq@(FromThen expr1 expr2)) res_ty
- = tcAddErrCtxt (arithSeqCtxt in_expr) $
- unifyListTy res_ty `thenTc` \ elt_ty ->
- tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
- tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
+ = addErrCtxt (arithSeqCtxt in_expr) $
+ unifyListTy res_ty `thenM` \ elt_ty ->
+ tcMonoExpr expr1 elt_ty `thenM` \ expr1' ->
+ tcMonoExpr expr2 elt_ty `thenM` \ expr2' ->
newMethodFromName (ArithSeqOrigin seq)
- elt_ty enumFromThenName `thenNF_Tc` \ enum_from_then ->
+ elt_ty enumFromThenName `thenM` \ enum_from_then ->
+
+ returnM (ArithSeqOut (HsVar enum_from_then) (FromThen expr1' expr2'))
- returnTc (ArithSeqOut (HsVar (instToId enum_from_then))
- (FromThen expr1' expr2'),
- lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_then)
tcMonoExpr in_expr@(ArithSeqIn seq@(FromTo expr1 expr2)) res_ty
- = tcAddErrCtxt (arithSeqCtxt in_expr) $
- unifyListTy res_ty `thenTc` \ elt_ty ->
- tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
- tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
+ = addErrCtxt (arithSeqCtxt in_expr) $
+ unifyListTy res_ty `thenM` \ elt_ty ->
+ tcMonoExpr expr1 elt_ty `thenM` \ expr1' ->
+ tcMonoExpr expr2 elt_ty `thenM` \ expr2' ->
newMethodFromName (ArithSeqOrigin seq)
- elt_ty enumFromToName `thenNF_Tc` \ enum_from_to ->
+ elt_ty enumFromToName `thenM` \ enum_from_to ->
- returnTc (ArithSeqOut (HsVar (instToId enum_from_to))
- (FromTo expr1' expr2'),
- lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_to)
+ returnM (ArithSeqOut (HsVar enum_from_to) (FromTo expr1' expr2'))
tcMonoExpr in_expr@(ArithSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty
- = tcAddErrCtxt (arithSeqCtxt in_expr) $
- unifyListTy res_ty `thenTc` \ elt_ty ->
- tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
- tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
- tcMonoExpr expr3 elt_ty `thenTc` \ (expr3',lie3) ->
+ = addErrCtxt (arithSeqCtxt in_expr) $
+ unifyListTy res_ty `thenM` \ elt_ty ->
+ tcMonoExpr expr1 elt_ty `thenM` \ expr1' ->
+ tcMonoExpr expr2 elt_ty `thenM` \ expr2' ->
+ tcMonoExpr expr3 elt_ty `thenM` \ expr3' ->
newMethodFromName (ArithSeqOrigin seq)
- elt_ty enumFromThenToName `thenNF_Tc` \ eft ->
+ elt_ty enumFromThenToName `thenM` \ eft ->
- returnTc (ArithSeqOut (HsVar (instToId eft))
- (FromThenTo expr1' expr2' expr3'),
- lie1 `plusLIE` lie2 `plusLIE` lie3 `plusLIE` unitLIE eft)
+ returnM (ArithSeqOut (HsVar eft) (FromThenTo expr1' expr2' expr3'))
tcMonoExpr in_expr@(PArrSeqIn seq@(FromTo expr1 expr2)) res_ty
- = tcAddErrCtxt (parrSeqCtxt in_expr) $
- unifyPArrTy res_ty `thenTc` \ elt_ty ->
- tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
- tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
+ = addErrCtxt (parrSeqCtxt in_expr) $
+ unifyPArrTy res_ty `thenM` \ elt_ty ->
+ tcMonoExpr expr1 elt_ty `thenM` \ expr1' ->
+ tcMonoExpr expr2 elt_ty `thenM` \ expr2' ->
newMethodFromName (PArrSeqOrigin seq)
- elt_ty enumFromToPName `thenNF_Tc` \ enum_from_to ->
+ elt_ty enumFromToPName `thenM` \ enum_from_to ->
- returnTc (PArrSeqOut (HsVar (instToId enum_from_to))
- (FromTo expr1' expr2'),
- lie1 `plusLIE` lie2 `plusLIE` unitLIE enum_from_to)
+ returnM (PArrSeqOut (HsVar enum_from_to) (FromTo expr1' expr2'))
tcMonoExpr in_expr@(PArrSeqIn seq@(FromThenTo expr1 expr2 expr3)) res_ty
- = tcAddErrCtxt (parrSeqCtxt in_expr) $
- unifyPArrTy res_ty `thenTc` \ elt_ty ->
- tcMonoExpr expr1 elt_ty `thenTc` \ (expr1',lie1) ->
- tcMonoExpr expr2 elt_ty `thenTc` \ (expr2',lie2) ->
- tcMonoExpr expr3 elt_ty `thenTc` \ (expr3',lie3) ->
+ = addErrCtxt (parrSeqCtxt in_expr) $
+ unifyPArrTy res_ty `thenM` \ elt_ty ->
+ tcMonoExpr expr1 elt_ty `thenM` \ expr1' ->
+ tcMonoExpr expr2 elt_ty `thenM` \ expr2' ->
+ tcMonoExpr expr3 elt_ty `thenM` \ expr3' ->
newMethodFromName (PArrSeqOrigin seq)
- elt_ty enumFromThenToPName `thenNF_Tc` \ eft ->
+ elt_ty enumFromThenToPName `thenM` \ eft ->
- returnTc (PArrSeqOut (HsVar (instToId eft))
- (FromThenTo expr1' expr2' expr3'),
- lie1 `plusLIE` lie2 `plusLIE` lie3 `plusLIE` unitLIE eft)
+ returnM (PArrSeqOut (HsVar eft) (FromThenTo expr1' expr2' expr3'))
tcMonoExpr (PArrSeqIn _) _
= panic "TcExpr.tcMonoExpr: Infinite parallel array!"
-- let it through
\end{code}
+
+%************************************************************************
+%* *
+ Template Haskell
+%* *
+%************************************************************************
+
+\begin{code}
+#ifdef GHCI /* Only if bootstrapped */
+ -- Rename excludes these cases otherwise
+
+tcMonoExpr (HsSplice n expr loc) res_ty = addSrcLoc loc (tcSpliceExpr n expr res_ty)
+
+tcMonoExpr (HsBracket brack loc) res_ty
+ = addSrcLoc loc $
+ getStage `thenM` \ level ->
+ case bracketOK level of {
+ Nothing -> failWithTc (illegalBracket level) ;
+ Just next_level ->
+
+ -- Typecheck expr to make sure it is valid,
+ -- but throw away the results. We'll type check
+ -- it again when we actually use it.
+ newMutVar [] `thenM` \ pending_splices ->
+ getLIEVar `thenM` \ lie_var ->
+
+ setStage (Brack next_level pending_splices lie_var) (
+ getLIE (tcBracket brack)
+ ) `thenM` \ (meta_ty, lie) ->
+ tcSimplifyBracket lie `thenM_`
+
+ unifyTauTy res_ty meta_ty `thenM_`
+
+ -- Return the original expression, not the type-decorated one
+ readMutVar pending_splices `thenM` \ pendings ->
+ returnM (HsBracketOut brack pendings)
+ }
+
+tcMonoExpr (HsReify (Reify flavour name)) res_ty
+ = addErrCtxt (ptext SLIT("At the reification of") <+> ppr name) $
+ tcMetaTy tycon_name `thenM` \ reify_ty ->
+ unifyTauTy res_ty reify_ty `thenM_`
+ returnM (HsReify (ReifyOut flavour name))
+ where
+ tycon_name = case flavour of
+ ReifyDecl -> DsMeta.decTyConName
+ ReifyType -> DsMeta.typTyConName
+ ReifyFixity -> pprPanic "tcMonoExpr: cant do reifyFixity yet" (ppr name)
+#endif GHCI
+\end{code}
+
%************************************************************************
%* *
\subsection{Implicit Parameter bindings}
\begin{code}
tcMonoExpr (HsWith expr binds is_with) res_ty
- = tcMonoExpr expr res_ty `thenTc` \ (expr', expr_lie) ->
- mapAndUnzip3Tc tcIPBind binds `thenTc` \ (avail_ips, binds', bind_lies) ->
+ = getLIE (tcMonoExpr expr res_ty) `thenM` \ (expr', expr_lie) ->
+ mapAndUnzipM tc_ip_bind binds `thenM` \ (avail_ips, binds') ->
-- If the binding binds ?x = E, we must now
-- discharge any ?x constraints in expr_lie
- tcSimplifyIPs avail_ips expr_lie `thenTc` \ (expr_lie', dict_binds) ->
+ tcSimplifyIPs avail_ips expr_lie `thenM` \ dict_binds ->
let
expr'' = HsLet (mkMonoBind dict_binds [] Recursive) expr'
in
- returnTc (HsWith expr'' binds' is_with, expr_lie' `plusLIE` plusLIEs bind_lies)
-
-tcIPBind (ip, expr)
- = newTyVarTy openTypeKind `thenTc` \ ty ->
- tcGetSrcLoc `thenTc` \ loc ->
- newIPDict (IPBind ip) ip ty `thenNF_Tc` \ (ip', ip_inst) ->
- tcMonoExpr expr ty `thenTc` \ (expr', lie) ->
- returnTc (ip_inst, (ip', expr'), lie)
+ returnM (HsWith expr'' binds' is_with)
+ where
+ tc_ip_bind (ip, expr)
+ = newTyVarTy openTypeKind `thenM` \ ty ->
+ getSrcLocM `thenM` \ loc ->
+ newIPDict (IPBind ip) ip ty `thenM` \ (ip', ip_inst) ->
+ tcMonoExpr expr ty `thenM` \ expr' ->
+ returnM (ip_inst, (ip', expr'))
\end{code}
+
+%************************************************************************
+%* *
+ Catch-all
+%* *
+%************************************************************************
+
+\begin{code}
+tcMonoExpr other _ = pprPanic "tcMonoExpr" (ppr other)
+\end{code}
+
+
%************************************************************************
%* *
\subsection{@tcApp@ typchecks an application}
tcApp :: RenamedHsExpr -> [RenamedHsExpr] -- Function and args
-> TcType -- Expected result type of application
- -> TcM (TcExpr, LIE) -- Translated fun and args
+ -> TcM TcExpr -- Translated fun and args
tcApp (HsApp e1 e2) args res_ty
= tcApp e1 (e2:args) res_ty -- Accumulate the arguments
tcApp fun args res_ty
= -- First type-check the function
- tcExpr_id fun `thenTc` \ (fun', lie_fun, fun_ty) ->
+ tcExpr_id fun `thenM` \ (fun', fun_ty) ->
- tcAddErrCtxt (wrongArgsCtxt "too many" fun args) (
- traceTc (text "tcApp" <+> (ppr fun $$ ppr fun_ty)) `thenNF_Tc_`
+ addErrCtxt (wrongArgsCtxt "too many" fun args) (
+ traceTc (text "tcApp" <+> (ppr fun $$ ppr fun_ty)) `thenM_`
split_fun_ty fun_ty (length args)
- ) `thenTc` \ (expected_arg_tys, actual_result_ty) ->
+ ) `thenM` \ (expected_arg_tys, actual_result_ty) ->
-- Now typecheck the args
- mapAndUnzipTc (tcArg fun)
- (zip3 args expected_arg_tys [1..]) `thenTc` \ (args', lie_args_s) ->
+ mappM (tcArg fun)
+ (zip3 args expected_arg_tys [1..]) `thenM` \ args' ->
-- Unify with expected result after type-checking the args
-- so that the info from args percolates to actual_result_ty.
-- This is when we might detect a too-few args situation.
-- (One can think of cases when the opposite order would give
-- a better error message.)
- tcAddErrCtxtM (checkArgsCtxt fun args res_ty actual_result_ty)
- (tcSubExp res_ty actual_result_ty) `thenTc` \ (co_fn, lie_res) ->
+ addErrCtxtM (checkArgsCtxt fun args res_ty actual_result_ty)
+ (tcSubExp res_ty actual_result_ty) `thenM` \ co_fn ->
- returnTc (co_fn <$> foldl HsApp fun' args',
- lie_res `plusLIE` lie_fun `plusLIE` plusLIEs lie_args_s)
+ returnM (co_fn <$> foldl HsApp fun' args')
-- If an error happens we try to figure out whether the
-- function has been given too many or too few arguments,
-- and say so
checkArgsCtxt fun args expected_res_ty actual_res_ty tidy_env
- = zonkTcType expected_res_ty `thenNF_Tc` \ exp_ty' ->
- zonkTcType actual_res_ty `thenNF_Tc` \ act_ty' ->
+ = zonkTcType expected_res_ty `thenM` \ exp_ty' ->
+ zonkTcType actual_res_ty `thenM` \ act_ty' ->
let
(env1, exp_ty'') = tidyOpenType tidy_env exp_ty'
(env2, act_ty'') = tidyOpenType env1 act_ty'
| len_exp_args > len_act_args = wrongArgsCtxt "too many" fun args
| otherwise = appCtxt fun args
in
- returnNF_Tc (env2, message)
+ returnM (env2, message)
split_fun_ty :: TcType -- The type of the function
TcType) -- Function result types
split_fun_ty fun_ty 0
- = returnTc ([], fun_ty)
+ = returnM ([], fun_ty)
split_fun_ty fun_ty n
= -- Expect the function to have type A->B
- unifyFunTy fun_ty `thenTc` \ (arg_ty, res_ty) ->
- split_fun_ty res_ty (n-1) `thenTc` \ (arg_tys, final_res_ty) ->
- returnTc (arg_ty:arg_tys, final_res_ty)
+ unifyFunTy fun_ty `thenM` \ (arg_ty, res_ty) ->
+ split_fun_ty res_ty (n-1) `thenM` \ (arg_tys, final_res_ty) ->
+ returnM (arg_ty:arg_tys, final_res_ty)
\end{code}
\begin{code}
tcArg :: RenamedHsExpr -- The function (for error messages)
-> (RenamedHsExpr, TcSigmaType, Int) -- Actual argument and expected arg type
- -> TcM (TcExpr, LIE) -- Resulting argument and LIE
+ -> TcM TcExpr -- Resulting argument and LIE
tcArg the_fun (arg, expected_arg_ty, arg_no)
- = tcAddErrCtxt (funAppCtxt the_fun arg arg_no) $
+ = addErrCtxt (funAppCtxt the_fun arg arg_no) $
tcExpr arg expected_arg_ty
\end{code}
b) perhaps fewer separated lambdas
\begin{code}
-tcId :: Name -> NF_TcM (TcExpr, LIE, TcType)
+tcId :: Name -> TcM (TcExpr, TcType)
tcId name -- Look up the Id and instantiate its type
- = tcLookupId name `thenNF_Tc` \ id ->
- case isDataConWrapId_maybe id of
- Nothing -> loop (HsVar id) emptyLIE (idType id)
- Just data_con -> inst_data_con id data_con
+ = tcLookupIdLvl name `thenM` \ (id, bind_lvl) ->
+
+ -- Check for cross-stage lifting
+#ifdef GHCI
+ getStage `thenM` \ use_stage ->
+ case use_stage of
+ Brack use_lvl ps_var lie_var
+ | use_lvl > bind_lvl && not (isExternalName name)
+ -> -- E.g. \x -> [| h x |]
+ -- We must behave as if the reference to x was
+ -- h $(lift x)
+ -- We use 'x' itself as the splice proxy, used by
+ -- the desugarer to stitch it all back together
+ -- NB: isExernalName is true of top level things,
+ -- and false of nested bindings
+
+ let
+ id_ty = idType id
+ in
+ checkTc (isTauTy id_ty) (polySpliceErr id) `thenM_`
+ -- If x is polymorphic, its occurrence sites might
+ -- have different instantiations, so we can't use plain
+ -- 'x' as the splice proxy name. I don't know how to
+ -- solve this, and it's probably unimportant, so I'm
+ -- just going to flag an error for now
+
+ setLIEVar lie_var (
+ newMethodFromName orig id_ty DsMeta.liftName `thenM` \ lift ->
+ -- Put the 'lift' constraint into the right LIE
+
+ -- Update the pending splices
+ readMutVar ps_var `thenM` \ ps ->
+ writeMutVar ps_var ((name, HsApp (HsVar lift) (HsVar id)) : ps) `thenM_`
+
+ returnM (HsVar id, id_ty))
+
+ other ->
+ let
+ use_lvl = metaLevel use_stage
+ in
+ checkTc (wellStaged bind_lvl use_lvl)
+ (badStageErr id bind_lvl use_lvl) `thenM_`
+#endif
+ -- This is the bit that handles the no-Template-Haskell case
+ case isDataConWrapId_maybe id of
+ Nothing -> loop (HsVar id) (idType id)
+ Just data_con -> inst_data_con id data_con
+
where
orig = OccurrenceOf name
- loop (HsVar fun_id) lie fun_ty
+ loop (HsVar fun_id) fun_ty
| want_method_inst fun_ty
- = tcInstType VanillaTv fun_ty `thenNF_Tc` \ (tyvars, theta, tau) ->
+ = tcInstType VanillaTv fun_ty `thenM` \ (tyvars, theta, tau) ->
newMethodWithGivenTy orig fun_id
- (mkTyVarTys tyvars) theta tau `thenNF_Tc` \ meth ->
- loop (HsVar (instToId meth))
- (unitLIE meth `plusLIE` lie) tau
+ (mkTyVarTys tyvars) theta tau `thenM` \ meth_id ->
+ loop (HsVar meth_id) tau
- loop fun lie fun_ty
+ loop fun fun_ty
| isSigmaTy fun_ty
- = tcInstCall orig fun_ty `thenNF_Tc` \ (inst_fn, inst_lie, tau) ->
- loop (inst_fn fun) (inst_lie `plusLIE` lie) tau
+ = tcInstCall orig fun_ty `thenM` \ (inst_fn, tau) ->
+ loop (inst_fn fun) tau
| otherwise
- = returnNF_Tc (fun, lie, fun_ty)
+ = returnM (fun, fun_ty)
want_method_inst fun_ty
| opt_NoMethodSharing = False
-- constraints for their silly theta, which no longer appears in
-- the type of dataConWrapId. It's dual to TcPat.tcConstructor
inst_data_con id data_con
- = tcInstDataCon orig data_con `thenNF_Tc` \ (ty_args, ex_dicts, arg_tys, result_ty, stupid_lie, ex_lie, _) ->
- returnNF_Tc (mkHsDictApp (mkHsTyApp (HsVar id) ty_args) ex_dicts,
- stupid_lie `plusLIE` ex_lie,
- mkFunTys arg_tys result_ty)
+ = tcInstDataCon orig data_con `thenM` \ (ty_args, ex_dicts, arg_tys, result_ty, _) ->
+ extendLIEs ex_dicts `thenM_`
+ returnM (mkHsDictApp (mkHsTyApp (HsVar id) ty_args) (map instToId ex_dicts),
+ mkFunTys arg_tys result_ty)
\end{code}
Typecheck expression which in most cases will be an Id.
so we must create a HoleTyVarTy to pass in as the expected tyvar.
\begin{code}
-tcExpr_id :: RenamedHsExpr -> TcM (TcExpr, LIE, TcType)
+tcExpr_id :: RenamedHsExpr -> TcM (TcExpr, TcType)
tcExpr_id (HsVar name) = tcId name
-tcExpr_id expr = newHoleTyVarTy `thenNF_Tc` \ id_ty ->
- tcMonoExpr expr id_ty `thenTc` \ (expr', lie_id) ->
- readHoleResult id_ty `thenTc` \ id_ty' ->
- returnTc (expr', lie_id, id_ty')
-\end{code}
-
-
-%************************************************************************
-%* *
-\subsection{@tcDoStmts@ typechecks a {\em list} of do statements}
-%* *
-%************************************************************************
-
-\begin{code}
--- I don't like this lumping together of do expression and list/array
--- comprehensions; creating the monad instances is entirely pointless in the
--- latter case; I'll leave the list case as it is for the moment, but handle
--- arrays extra (would be better to handle arrays and lists together, though)
--- -=chak
---
-tcDoStmts PArrComp stmts src_loc res_ty
- =
- ASSERT( notNull stmts )
- tcAddSrcLoc src_loc $
-
- unifyPArrTy res_ty `thenTc` \elt_ty ->
- let tc_ty = mkTyConTy parrTyCon
- m_ty = (mkPArrTy, elt_ty)
- in
- tcStmts (DoCtxt PArrComp) m_ty stmts `thenTc` \(stmts', stmts_lie) ->
- returnTc (HsDoOut PArrComp stmts'
- undefined -- don't touch!
- res_ty src_loc,
- stmts_lie)
-
-tcDoStmts do_or_lc stmts src_loc res_ty
- = -- get the Monad and MonadZero classes
- -- create type consisting of a fresh monad tyvar
- ASSERT( notNull stmts )
- tcAddSrcLoc src_loc $
-
- -- If it's a comprehension we're dealing with,
- -- force it to be a list comprehension.
- -- (as of Haskell 98, monad comprehensions are no more.)
- -- Similarily, array comprehensions must involve parallel arrays types
- -- -=chak
- (case do_or_lc of
- ListComp -> unifyListTy res_ty `thenTc` \ elt_ty ->
- returnNF_Tc (mkTyConTy listTyCon, (mkListTy, elt_ty))
-
- PArrComp -> panic "TcExpr.tcDoStmts: How did we get here?!?"
-
- _ -> newTyVarTy (mkArrowKind liftedTypeKind liftedTypeKind) `thenNF_Tc` \ m_ty ->
- newTyVarTy liftedTypeKind `thenNF_Tc` \ elt_ty ->
- unifyTauTy res_ty (mkAppTy m_ty elt_ty) `thenTc_`
- returnNF_Tc (m_ty, (mkAppTy m_ty, elt_ty))
- ) `thenNF_Tc` \ (tc_ty, m_ty) ->
-
- tcStmts (DoCtxt do_or_lc) m_ty stmts `thenTc` \ (stmts', stmts_lie) ->
-
- -- Build the then and zero methods in case we need them
- -- It's important that "then" and "return" appear just once in the final LIE,
- -- not only for typechecker efficiency, but also because otherwise during
- -- simplification we end up with silly stuff like
- -- then = case d of (t,r) -> t
- -- then = then
- -- where the second "then" sees that it already exists in the "available" stuff.
- --
- mapNF_Tc (newMethodFromName DoOrigin tc_ty)
- [returnMName, failMName, bindMName, thenMName] `thenNF_Tc` \ insts ->
-
- returnTc (HsDoOut do_or_lc stmts'
- (map instToId insts)
- res_ty src_loc,
- stmts_lie `plusLIE` mkLIE insts)
+tcExpr_id expr = newHoleTyVarTy `thenM` \ id_ty ->
+ tcMonoExpr expr id_ty `thenM` \ expr' ->
+ readHoleResult id_ty `thenM` \ id_ty' ->
+ returnM (expr', id_ty')
\end{code}
:: TyCon -- Type constructor for the record
-> [TcType] -- Args of this type constructor
-> RenamedRecordBinds
- -> TcM (TcRecordBinds, LIE)
+ -> TcM TcRecordBinds
tcRecordBinds tycon ty_args rbinds
- = mapAndUnzipTc do_bind rbinds `thenTc` \ (rbinds', lies) ->
- returnTc (rbinds', plusLIEs lies)
+ = mappM do_bind rbinds
where
tenv = mkTopTyVarSubst (tyConTyVars tycon) ty_args
- do_bind (field_lbl_name, rhs, pun_flag)
- = tcLookupGlobalId field_lbl_name `thenNF_Tc` \ sel_id ->
+ do_bind (field_lbl_name, rhs)
+ = addErrCtxt (fieldCtxt field_lbl_name) $
+ tcLookupId field_lbl_name `thenM` \ sel_id ->
let
field_lbl = recordSelectorFieldLabel sel_id
field_ty = substTy tenv (fieldLabelType field_lbl)
-- The caller of tcRecordBinds has already checked
-- that all the fields come from the same type
- tcExpr rhs field_ty `thenTc` \ (rhs', lie) ->
+ tcExpr rhs field_ty `thenM` \ rhs' ->
- returnTc ((sel_id, rhs', pun_flag), lie)
+ returnM (sel_id, rhs')
badFields rbinds data_con
- = [field_name | (field_name, _, _) <- rbinds,
- not (field_name `elem` field_names)
- ]
+ = filter (not . (`elem` field_names)) (recBindFields rbinds)
where
field_names = map fieldLabelName (dataConFieldLabels data_con)
-missingFields rbinds data_con
- | null field_labels = ([], []) -- Not declared as a record;
- -- But C{} is still valid
- | otherwise
- = (missing_strict_fields, other_missing_fields)
+checkMissingFields :: DataCon -> RenamedRecordBinds -> TcM ()
+checkMissingFields data_con rbinds
+ | null field_labels -- Not declared as a record;
+ -- But C{} is still valid if no strict fields
+ = if any isMarkedStrict field_strs then
+ -- Illegal if any arg is strict
+ addErrTc (missingStrictFields data_con [])
+ else
+ returnM ()
+
+ | otherwise -- A record
+ = checkM (null missing_s_fields)
+ (addErrTc (missingStrictFields data_con missing_s_fields)) `thenM_`
+
+ doptM Opt_WarnMissingFields `thenM` \ warn ->
+ checkM (not (warn && notNull missing_ns_fields))
+ (warnTc True (missingFields data_con missing_ns_fields))
+
where
- missing_strict_fields
+ missing_s_fields
= [ fl | (fl, str) <- field_info,
isMarkedStrict str,
not (fieldLabelName fl `elem` field_names_used)
]
- other_missing_fields
+ missing_ns_fields
= [ fl | (fl, str) <- field_info,
not (isMarkedStrict str),
not (fieldLabelName fl `elem` field_names_used)
]
- field_names_used = [ field_name | (field_name, _, _) <- rbinds ]
+ field_names_used = recBindFields rbinds
field_labels = dataConFieldLabels data_con
field_info = zipEqual "missingFields"
field_labels
- (dropList ex_theta (dataConStrictMarks data_con))
+ field_strs
+
+ field_strs = dropList ex_theta (dataConStrictMarks data_con)
-- The 'drop' is because dataConStrictMarks
-- includes the existential dictionaries
(_, _, _, ex_theta, _, _) = dataConSig data_con
%************************************************************************
\begin{code}
-tcMonoExprs :: [RenamedHsExpr] -> [TcType] -> TcM ([TcExpr], LIE)
+tcMonoExprs :: [RenamedHsExpr] -> [TcType] -> TcM [TcExpr]
-tcMonoExprs [] [] = returnTc ([], emptyLIE)
+tcMonoExprs [] [] = returnM []
tcMonoExprs (expr:exprs) (ty:tys)
- = tcMonoExpr expr ty `thenTc` \ (expr', lie1) ->
- tcMonoExprs exprs tys `thenTc` \ (exprs', lie2) ->
- returnTc (expr':exprs', lie1 `plusLIE` lie2)
+ = tcMonoExpr expr ty `thenM` \ expr' ->
+ tcMonoExprs exprs tys `thenM` \ exprs' ->
+ returnM (expr':exprs')
\end{code}
Overloaded literals.
\begin{code}
-tcLit :: HsLit -> TcType -> TcM (TcExpr, LIE)
+tcLit :: HsLit -> TcType -> TcM TcExpr
tcLit (HsLitLit s _) res_ty
- = tcLookupClass cCallableClassName `thenNF_Tc` \ cCallableClass ->
+ = tcLookupClass cCallableClassName `thenM` \ cCallableClass ->
newDicts (LitLitOrigin (unpackFS s))
- [mkClassPred cCallableClass [res_ty]] `thenNF_Tc` \ dicts ->
- returnTc (HsLit (HsLitLit s res_ty), mkLIE dicts)
+ [mkClassPred cCallableClass [res_ty]] `thenM` \ dicts ->
+ extendLIEs dicts `thenM_`
+ returnM (HsLit (HsLitLit s res_ty))
tcLit lit res_ty
- = unifyTauTy res_ty (simpleHsLitTy lit) `thenTc_`
- returnTc (HsLit lit, emptyLIE)
+ = unifyTauTy res_ty (hsLitType lit) `thenM_`
+ returnM (HsLit lit)
\end{code}
%* *
%************************************************************************
-Mini-utils:
-
Boring and alphabetical:
\begin{code}
arithSeqCtxt expr
= hang (ptext SLIT("In an arithmetic sequence:")) 4 (ppr expr)
+
+badStageErr id bind_lvl use_lvl
+ = ptext SLIT("Stage error:") <+> quotes (ppr id) <+>
+ hsep [ptext SLIT("is bound at stage") <+> ppr bind_lvl,
+ ptext SLIT("but used at stage") <+> ppr use_lvl]
+
parrSeqCtxt expr
= hang (ptext SLIT("In a parallel array sequence:")) 4 (ppr expr)
= hang (ptext SLIT("When checking the type signature of the expression:"))
4 (ppr expr)
+exprCtxt expr
+ = hang (ptext SLIT("In the expression:")) 4 (ppr expr)
+
+fieldCtxt field_name
+ = ptext SLIT("In the") <+> quotes (ppr field_name) <+> ptext SLIT("field of a record")
+
+funAppCtxt fun arg arg_no
+ = hang (hsep [ ptext SLIT("In the"), speakNth arg_no, ptext SLIT("argument of"),
+ quotes (ppr fun) <> text ", namely"])
+ 4 (quotes (ppr arg))
+
listCtxt expr
= hang (ptext SLIT("In the list element:")) 4 (ppr expr)
predCtxt expr
= hang (ptext SLIT("In the predicate expression:")) 4 (ppr expr)
-exprCtxt expr
- = hang (ptext SLIT("In the expression:")) 4 (ppr expr)
-
-funAppCtxt fun arg arg_no
- = hang (hsep [ ptext SLIT("In the"), speakNth arg_no, ptext SLIT("argument of"),
- quotes (ppr fun) <> text ", namely"])
- 4 (quotes (ppr arg))
-
-wrongArgsCtxt too_many_or_few fun args
- = hang (ptext SLIT("Probable cause:") <+> quotes (ppr fun)
- <+> ptext SLIT("is applied to") <+> text too_many_or_few
- <+> ptext SLIT("arguments in the call"))
- 4 (parens (ppr the_app))
- where
- the_app = foldl HsApp fun args -- Used in error messages
+illegalBracket level
+ = ptext SLIT("Illegal bracket at level") <+> ppr level
appCtxt fun args
= ptext SLIT("In the application") <+> quotes (ppr the_app)
badFieldsUpd rbinds
= hang (ptext SLIT("No constructor has all these fields:"))
- 4 (pprQuotedList fields)
- where
- fields = [field | (field, _, _) <- rbinds]
+ 4 (pprQuotedList (recBindFields rbinds))
recordUpdCtxt expr = ptext SLIT("In the record update:") <+> ppr expr
recordConCtxt expr = ptext SLIT("In the record construction:") <+> ppr expr
notSelector field
= hsep [quotes (ppr field), ptext SLIT("is not a record selector")]
-missingStrictFieldCon :: Name -> FieldLabel -> SDoc
-missingStrictFieldCon con field
- = hsep [ptext SLIT("Constructor") <+> quotes (ppr con),
- ptext SLIT("does not have the required strict field"), quotes (ppr field)]
+missingStrictFields :: DataCon -> [FieldLabel] -> SDoc
+missingStrictFields con fields
+ = header <> rest
+ where
+ rest | null fields = empty -- Happens for non-record constructors
+ -- with strict fields
+ | otherwise = colon <+> pprWithCommas ppr fields
+
+ header = ptext SLIT("Constructor") <+> quotes (ppr con) <+>
+ ptext SLIT("does not have the required strict field(s)")
+
-missingFieldCon :: Name -> FieldLabel -> SDoc
-missingFieldCon con field
- = hsep [ptext SLIT("Field") <+> quotes (ppr field),
- ptext SLIT("is not initialised")]
+missingFields :: DataCon -> [FieldLabel] -> SDoc
+missingFields con fields
+ = ptext SLIT("Fields of") <+> quotes (ppr con) <+> ptext SLIT("not initialised:")
+ <+> pprWithCommas ppr fields
+
+polySpliceErr :: Id -> SDoc
+polySpliceErr id
+ = ptext SLIT("Can't splice the polymorphic local variable") <+> quotes (ppr id)
+
+wrongArgsCtxt too_many_or_few fun args
+ = hang (ptext SLIT("Probable cause:") <+> quotes (ppr fun)
+ <+> ptext SLIT("is applied to") <+> text too_many_or_few
+ <+> ptext SLIT("arguments in the call"))
+ 4 (parens (ppr the_app))
+ where
+ the_app = foldl HsApp fun args -- Used in error messages
\end{code}
projects / ghc-hetmet.git / blobdiff