X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Ftypecheck%2FTcArrows.lhs;h=082f9da797ba1b3080c53d8c5c2547101d155ed3;hp=3bfa9b4757f0819a346c2a6ac4df438460fa0e98;hb=c1500e4888be2341c0b6e6897f494766c86feba0;hpb=0065d5ab628975892cea1ec7303f968c3338cbe1 diff --git a/compiler/typecheck/TcArrows.lhs b/compiler/typecheck/TcArrows.lhs index 3bfa9b4..082f9da 100644 --- a/compiler/typecheck/TcArrows.lhs +++ b/compiler/typecheck/TcArrows.lhs @@ -1,41 +1,40 @@ % +% (c) The University of Glasgow 2006 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998 % -\section{Typecheck arrow notation} +Typecheck arrow notation \begin{code} module TcArrows ( tcProc ) where -#include "HsVersions.h" - import {-# SOURCE #-} TcExpr( tcMonoExpr, tcInferRho ) import HsSyn -import TcHsSyn ( mkHsDictLet ) - -import TcMatches ( matchCtxt, tcStmts, tcMDoStmt, tcGuardStmt, - TcMatchCtxt(..), tcMatchesCase ) - -import TcType ( TcType, TcTauType, BoxyRhoType, mkFunTys, mkTyConApp, - mkTyVarTy, mkAppTys, tcSplitTyConApp_maybe, tcEqType, - SkolemInfo(..) ) -import TcMType ( newFlexiTyVarTy, tcInstSkolTyVars, zonkTcType ) -import TcBinds ( tcLocalBinds ) -import TcSimplify ( tcSimplifyCheck ) -import TcPat ( tcPat, tcPats, PatCtxt(..) ) -import TcUnify ( checkSigTyVarsWrt, boxySplitAppTy ) +import TcHsSyn + +import TcMatches + +import TcType +import TcMType +import TcBinds +import TcSimplify +import TcPat +import TcUnify import TcRnMonad -import Inst ( tcSyntaxName ) -import Name ( Name ) -import TysWiredIn ( boolTy, pairTyCon ) +import Coercion +import Inst +import Name +import TysWiredIn import VarSet -import TysPrim ( alphaTyVar ) -import Type ( Kind, mkArrowKinds, liftedTypeKind, openTypeKind, tyVarsOfTypes ) +import TysPrim +import Type -import SrcLoc ( Located(..) ) +import SrcLoc import Outputable -import Util ( lengthAtLeast ) +import FastString +import Util +import Control.Monad \end{code} %************************************************************************ @@ -47,16 +46,18 @@ import Util ( lengthAtLeast ) \begin{code} tcProc :: InPat Name -> LHsCmdTop Name -- proc pat -> expr -> BoxyRhoType -- Expected type of whole proc expression - -> TcM (OutPat TcId, LHsCmdTop TcId) + -> TcM (OutPat TcId, LHsCmdTop TcId, CoercionI) tcProc pat cmd exp_ty = newArrowScope $ - do { (exp_ty1, res_ty) <- boxySplitAppTy exp_ty - ; (arr_ty, arg_ty) <- boxySplitAppTy exp_ty1 + do { ((exp_ty1, res_ty), coi) <- boxySplitAppTy exp_ty + ; ((arr_ty, arg_ty), coi1) <- boxySplitAppTy exp_ty1 ; let cmd_env = CmdEnv { cmd_arr = arr_ty } - ; (pat', cmd') <- tcPat LamPat pat arg_ty res_ty $ \ res_ty' -> - tcCmdTop cmd_env cmd ([], res_ty') - ; return (pat', cmd') } + ; (pat', cmd') <- tcProcPat pat arg_ty res_ty $ + tcCmdTop cmd_env cmd [] + ; let res_coi = mkTransCoI coi (mkAppTyCoI exp_ty1 coi1 res_ty IdCo) + ; return (pat', cmd', res_coi) + } \end{code} @@ -79,20 +80,29 @@ mkCmdArrTy env t1 t2 = mkAppTys (cmd_arr env) [t1, t2] --------------------------------------- tcCmdTop :: CmdEnv -> LHsCmdTop Name - -> (CmdStack, TcTauType) -- Expected result type; always a monotype - -- We know exactly how many cmd args are expected, - -- albeit perhaps not their types; so we can pass - -- in a CmdStack + -> CmdStack + -> TcTauType -- Expected result type; always a monotype + -- We know exactly how many cmd args are expected, + -- albeit perhaps not their types; so we can pass + -- in a CmdStack -> TcM (LHsCmdTop TcId) -tcCmdTop env (L loc (HsCmdTop cmd _ _ names)) (cmd_stk, res_ty) +tcCmdTop env (L loc (HsCmdTop cmd _ _ names)) cmd_stk res_ty = setSrcSpan loc $ - do { cmd' <- tcCmd env cmd (cmd_stk, res_ty) + do { cmd' <- tcGuardedCmd env cmd cmd_stk res_ty ; names' <- mapM (tcSyntaxName ProcOrigin (cmd_arr env)) names ; return (L loc $ HsCmdTop cmd' cmd_stk res_ty names') } ---------------------------------------- +tcGuardedCmd :: CmdEnv -> LHsExpr Name -> CmdStack + -> TcTauType -> TcM (LHsExpr TcId) +-- A wrapper that deals with the refinement (if any) +tcGuardedCmd env expr stk res_ty + = do { body <- tcCmd env expr (stk, res_ty) + ; return body + } + tcCmd :: CmdEnv -> LHsExpr Name -> (CmdStack, TcTauType) -> TcM (LHsExpr TcId) -- The main recursive function tcCmd env (L loc expr) res_ty @@ -100,6 +110,7 @@ tcCmd env (L loc expr) res_ty { expr' <- tc_cmd env expr res_ty ; return (L loc expr') } +tc_cmd :: CmdEnv -> HsExpr Name -> (CmdStack, TcTauType) -> TcM (HsExpr TcId) tc_cmd env (HsPar cmd) res_ty = do { cmd' <- tcCmd env cmd res_ty ; return (HsPar cmd') } @@ -111,16 +122,15 @@ tc_cmd env (HsLet binds (L body_loc body)) res_ty ; return (HsLet binds' (L body_loc body')) } tc_cmd env in_cmd@(HsCase scrut matches) (stk, res_ty) - = addErrCtxt (cmdCtxt in_cmd) $ - addErrCtxt (caseScrutCtxt scrut) ( - tcInferRho scrut - ) `thenM` \ (scrut', scrut_ty) -> - tcMatchesCase match_ctxt scrut_ty matches res_ty `thenM` \ matches' -> - returnM (HsCase scrut' matches') + = addErrCtxt (cmdCtxt in_cmd) $ do + (scrut', scrut_ty) <- addErrCtxt (caseScrutCtxt scrut) $ + tcInferRho scrut + matches' <- tcMatchesCase match_ctxt scrut_ty matches res_ty + return (HsCase scrut' matches') where match_ctxt = MC { mc_what = CaseAlt, mc_body = mc_body } - mc_body body res_ty' = tcCmd env body (stk, res_ty') + mc_body body res_ty' = tcGuardedCmd env body stk res_ty' tc_cmd env (HsIf pred b1 b2) res_ty = do { pred' <- tcMonoExpr pred boolTy @@ -157,7 +167,6 @@ tc_cmd env cmd@(HsArrApp fun arg _ ho_app lr) (cmd_stk, res_ty) tc_cmd env cmd@(HsApp fun arg) (cmd_stk, res_ty) = addErrCtxt (cmdCtxt cmd) $ --- gaw 2004 FIX? do { arg_ty <- newFlexiTyVarTy openTypeKind ; fun' <- tcCmd env fun (arg_ty:cmd_stk, res_ty) @@ -169,10 +178,9 @@ tc_cmd env cmd@(HsApp fun arg) (cmd_stk, res_ty) ------------------------------------------- -- Lambda --- gaw 2004 -tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats maybe_rhs_sig grhss))] _)) +tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats _maybe_rhs_sig grhss))] _)) (cmd_stk, res_ty) - = addErrCtxt (matchCtxt match_ctxt match) $ + = addErrCtxt (pprMatchInCtxt match_ctxt match) $ do { -- Check the cmd stack is big enough ; checkTc (lengthAtLeast cmd_stk n_pats) @@ -180,7 +188,7 @@ tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats maybe_rhs_sig g -- Check the patterns, and the GRHSs inside ; (pats', grhss') <- setSrcSpan mtch_loc $ - tcPats LamPat pats cmd_stk res_ty $ + tcLamPats pats cmd_stk res_ty $ tc_grhss grhss ; let match' = L mtch_loc (Match pats' Nothing grhss') @@ -190,7 +198,7 @@ tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats maybe_rhs_sig g where n_pats = length pats stk' = drop n_pats cmd_stk - match_ctxt = LambdaExpr -- Maybe KappaExpr? + match_ctxt = (LambdaExpr :: HsMatchContext Name) -- Maybe KappaExpr? pg_ctxt = PatGuard match_ctxt tc_grhss (GRHSs grhss binds) res_ty @@ -199,18 +207,17 @@ tc_cmd env cmd@(HsLam (MatchGroup [L mtch_loc (match@(Match pats maybe_rhs_sig g ; return (GRHSs grhss' binds') } tc_grhs res_ty (GRHS guards body) - = do { (guards', rhs') <- tcStmts pg_ctxt tcGuardStmt - guards res_ty - (\res_ty' -> tcCmd env body (stk', res_ty')) + = do { (guards', rhs') <- tcStmts pg_ctxt tcGuardStmt guards res_ty $ + tcGuardedCmd env body stk' ; return (GRHS guards' rhs') } ------------------------------------------- -- Do notation -tc_cmd env cmd@(HsDo do_or_lc stmts body ty) (cmd_stk, res_ty) +tc_cmd env cmd@(HsDo do_or_lc stmts body _ty) (cmd_stk, res_ty) = do { checkTc (null cmd_stk) (nonEmptyCmdStkErr cmd) - ; (stmts', body') <- tcStmts do_or_lc tc_stmt stmts res_ty $ \ res_ty' -> - tcCmd env body ([], res_ty') + ; (stmts', body') <- tcStmts do_or_lc tc_stmt stmts res_ty $ + tcGuardedCmd env body [] ; return (HsDo do_or_lc stmts' body' res_ty) } where tc_stmt = tcMDoStmt tc_rhs @@ -232,8 +239,7 @@ tc_cmd env cmd@(HsDo do_or_lc stmts body ty) (cmd_stk, res_ty) tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty) = addErrCtxt (cmdCtxt cmd) $ do { cmds_w_tys <- zipWithM new_cmd_ty cmd_args [1..] - ; span <- getSrcSpanM - ; [w_tv] <- tcInstSkolTyVars (ArrowSkol span) [alphaTyVar] + ; [w_tv] <- tcInstSkolTyVars ArrowSkol [alphaTyVar] ; let w_ty = mkTyVarTy w_tv -- Just a convenient starting point -- a ((w,t1) .. tn) t @@ -246,7 +252,8 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty) -- Check expr ; (expr', lie) <- escapeArrowScope (getLIE (tcMonoExpr expr e_ty)) - ; inst_binds <- tcSimplifyCheck sig_msg [w_tv] [] lie + ; loc <- getInstLoc (SigOrigin ArrowSkol) + ; inst_binds <- tcSimplifyCheck loc [w_tv] [] lie -- Check that the polymorphic variable hasn't been unified with anything -- and is not free in res_ty or the cmd_stk (i.e. t, t1..tn) @@ -256,7 +263,9 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty) -- the s1..sm and check each cmd ; cmds' <- mapM (tc_cmd w_tv) cmds_w_tys - ; returnM (HsArrForm (mkHsTyLam [w_tv] (mkHsDictLet inst_binds expr')) fixity cmds') + ; return (HsArrForm (noLoc $ HsWrap (WpTyLam w_tv) + (unLoc $ mkHsDictLet inst_binds expr')) + fixity cmds') } where -- Make the types @@ -264,7 +273,6 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty) new_cmd_ty :: LHsCmdTop Name -> Int -> TcM (LHsCmdTop Name, Int, TcType, TcType, TcType) new_cmd_ty cmd i --- gaw 2004 FIX? = do { b_ty <- newFlexiTyVarTy arrowTyConKind ; tup_ty <- newFlexiTyVarTy liftedTypeKind -- We actually make a type variable for the tuple @@ -284,7 +292,7 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty) not (w_tv `elemVarSet` tyVarsOfTypes arg_tys)) (badFormFun i tup_ty') - ; tcCmdTop (env { cmd_arr = b }) cmd (arg_tys, s) } + ; tcCmdTop (env { cmd_arr = b }) cmd arg_tys s } unscramble :: TcType -> (TcType, [TcType]) -- unscramble ((w,s1) .. sn) = (w, [s1..sn]) @@ -295,17 +303,15 @@ tc_cmd env cmd@(HsArrForm expr fixity cmd_args) (cmd_stk, res_ty) (w,ss) = unscramble t in (w, s:ss) - other -> (ty, []) - - sig_msg = ptext SLIT("expected type of a command form") + _ -> (ty, []) ----------------------------------------------------------------- -- Base case for illegal commands -- This is where expressions that aren't commands get rejected -tc_cmd env cmd _ - = failWithTc (vcat [ptext SLIT("The expression"), nest 2 (ppr cmd), - ptext SLIT("was found where an arrow command was expected")]) +tc_cmd _ cmd _ + = failWithTc (vcat [ptext (sLit "The expression"), nest 2 (ppr cmd), + ptext (sLit "was found where an arrow command was expected")]) \end{code} @@ -317,6 +323,7 @@ tc_cmd env cmd _ \begin{code} +mkPairTy :: Type -> Type -> Type mkPairTy t1 t2 = mkTyConApp pairTyCon [t1,t2] arrowTyConKind :: Kind -- *->*->* @@ -331,20 +338,25 @@ arrowTyConKind = mkArrowKinds [liftedTypeKind, liftedTypeKind] liftedTypeKind %************************************************************************ \begin{code} -cmdCtxt cmd = ptext SLIT("In the command:") <+> ppr cmd +cmdCtxt :: HsExpr Name -> SDoc +cmdCtxt cmd = ptext (sLit "In the command:") <+> ppr cmd +caseScrutCtxt :: LHsExpr Name -> SDoc caseScrutCtxt cmd - = hang (ptext SLIT("In the scrutinee of a case command:")) 4 (ppr cmd) + = hang (ptext (sLit "In the scrutinee of a case command:")) 4 (ppr cmd) +nonEmptyCmdStkErr :: HsExpr Name -> SDoc nonEmptyCmdStkErr cmd - = hang (ptext SLIT("Non-empty command stack at command:")) + = hang (ptext (sLit "Non-empty command stack at command:")) 4 (ppr cmd) +kappaUnderflow :: HsExpr Name -> SDoc kappaUnderflow cmd - = hang (ptext SLIT("Command stack underflow at command:")) + = hang (ptext (sLit "Command stack underflow at command:")) 4 (ppr cmd) +badFormFun :: Int -> TcType -> SDoc badFormFun i tup_ty' - = hang (ptext SLIT("The type of the") <+> speakNth i <+> ptext SLIT("argument of a command form has the wrong shape")) - 4 (ptext SLIT("Argument type:") <+> ppr tup_ty') + = hang (ptext (sLit "The type of the") <+> speakNth i <+> ptext (sLit "argument of a command form has the wrong shape")) + 4 (ptext (sLit "Argument type:") <+> ppr tup_ty') \end{code}