%
+% (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}
%************************************************************************
\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}
---------------------------------------
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
{ 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') }
; 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
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)
-------------------------------------------
-- 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)
-- 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')
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
; 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
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
-- 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)
-- 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
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
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])
(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}
\begin{code}
+mkPairTy :: Type -> Type -> Type
mkPairTy t1 t2 = mkTyConApp pairTyCon [t1,t2]
arrowTyConKind :: Kind -- *->*->*
%************************************************************************
\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}
projects / ghc-hetmet.git / blobdiff