#include "HsVersions.h"
-import {-# SOURCE #-} TcExpr( tcCheckRho, tcInferRho )
+import {-# SOURCE #-} TcExpr( tcMonoExpr, tcInferRho )
import HsSyn
-import TcHsSyn ( mkHsLet )
+import TcHsSyn ( mkHsDictLet )
-import TcMatches ( TcStmtCtxt(..), tcMatchPats, matchCtxt, tcStmts,
- TcMatchCtxt(..), tcMatchesCase )
+import TcMatches ( matchCtxt, tcStmts, tcMDoStmt, tcGuardStmt,
+ TcMatchCtxt(..), tcMatchesCase )
-import TcType ( TcType, TcTauType, TcRhoType, mkFunTys, mkTyConApp,
+import TcType ( TcType, TcTauType, BoxyRhoType, mkFunTys, mkTyConApp,
mkTyVarTy, mkAppTys, tcSplitTyConApp_maybe, tcEqType,
SkolemInfo(..) )
-import TcMType ( newTyFlexiVarTy, newTyFlexiVarTys, tcSkolTyVars, zonkTcType )
-import TcBinds ( tcBindsAndThen )
+import TcMType ( newFlexiTyVarTy, tcInstSkolTyVars, zonkTcType )
+import TcBinds ( tcLocalBinds )
import TcSimplify ( tcSimplifyCheck )
-import TcUnify ( Expected(..), checkSigTyVarsWrt, zapExpectedTo )
+import TcPat ( tcPat, tcPats, PatCtxt(..) )
+import TcUnify ( checkSigTyVarsWrt, boxySplitAppTy )
import TcRnMonad
import Inst ( tcSyntaxName )
import Name ( Name )
\begin{code}
tcProc :: InPat Name -> LHsCmdTop Name -- proc pat -> expr
- -> Expected TcRhoType -- Expected type of whole proc expression
+ -> BoxyRhoType -- Expected type of whole proc expression
-> TcM (OutPat TcId, LHsCmdTop TcId)
tcProc pat cmd exp_ty
--- gaw 2004 FIX?
- = do { arr_ty <- newTyFlexiVarTy arrowTyConKind
- ; [arg_ty, res_ty] <- newTyFlexiVarTys 2 liftedTypeKind
- ; zapExpectedTo exp_ty (mkAppTys arr_ty [arg_ty,res_ty])
-
+ = newArrowScope $
+ do { (exp_ty1, res_ty) <- boxySplitAppTy exp_ty
+ ; (arr_ty, arg_ty) <- boxySplitAppTy exp_ty1
; let cmd_env = CmdEnv { cmd_arr = arr_ty }
- ; ([pat'], cmd') <- incProcLevel $
- tcMatchPats [pat] [Check arg_ty] (Check res_ty) $
- tcCmdTop cmd_env cmd ([], res_ty)
- -- The False says don't do GADT type refinement
- -- This is a conservative choice, but I'm not sure of the consequences
- -- of type refinement in the arrow world!
-
+ ; (pat', cmd') <- tcPat LamPat pat arg_ty res_ty $ \ res_ty' ->
+ tcCmdTop cmd_env cmd ([], res_ty')
; return (pat', cmd') }
\end{code}
\begin{code}
type CmdStack = [TcTauType]
-data CmdEnv = CmdEnv { cmd_arr :: TcType } -- The arrow type constructor, of kind *->*->*
+data CmdEnv
+ = CmdEnv {
+ cmd_arr :: TcType -- arrow type constructor, of kind *->*->*
+ }
mkCmdArrTy :: CmdEnv -> TcTauType -> TcTauType -> TcTauType
mkCmdArrTy env t1 t2 = mkAppTys (cmd_arr env) [t1, t2]
; return (HsPar cmd') }
tc_cmd env (HsLet binds (L body_loc body)) res_ty
- = tcBindsAndThen glue binds $
- setSrcSpan body_loc $
- tc_cmd env body res_ty
- where
- glue binds expr = HsLet [binds] (L body_loc expr)
+ = do { (binds', body') <- tcLocalBinds binds $
+ setSrcSpan body_loc $
+ tc_cmd env 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 (Check res_ty) `thenM` \ matches' ->
+ ) `thenM` \ (scrut', scrut_ty) ->
+ tcMatchesCase match_ctxt scrut_ty matches res_ty `thenM` \ matches' ->
returnM (HsCase scrut' matches')
where
match_ctxt = MC { mc_what = CaseAlt,
mc_body = mc_body }
- mc_body body (Check res_ty') = tcCmd env body (stk, res_ty')
+ mc_body body res_ty' = tcCmd env body (stk, res_ty')
tc_cmd env (HsIf pred b1 b2) res_ty
- = do { pred' <- tcCheckRho pred boolTy
+ = do { pred' <- tcMonoExpr pred boolTy
; b1' <- tcCmd env b1 res_ty
; b2' <- tcCmd env b2 res_ty
; return (HsIf pred' b1' b2')
tc_cmd env cmd@(HsArrApp fun arg _ ho_app lr) (cmd_stk, res_ty)
= addErrCtxt (cmdCtxt cmd) $
- do { arg_ty <- newTyFlexiVarTy openTypeKind
+ do { arg_ty <- newFlexiTyVarTy openTypeKind
; let fun_ty = mkCmdArrTy env (foldl mkPairTy arg_ty cmd_stk) res_ty
- ; fun' <- pop_arrow_binders (tcCheckRho fun fun_ty)
+ ; fun' <- select_arrow_scope (tcMonoExpr fun fun_ty)
- ; arg' <- tcCheckRho arg arg_ty
+ ; arg' <- tcMonoExpr arg arg_ty
; return (HsArrApp fun' arg' fun_ty ho_app lr) }
where
- -- Before type-checking f, remove the "arrow binders" from the
- -- environment in the (-<) case.
+ -- Before type-checking f, use the environment of the enclosing
+ -- proc for the (-<) case.
-- Local bindings, inside the enclosing proc, are not in scope
-- inside f. In the higher-order case (-<<), they are.
- pop_arrow_binders tc = case ho_app of
+ select_arrow_scope tc = case ho_app of
HsHigherOrderApp -> tc
- HsFirstOrderApp -> popArrowBinders tc
+ HsFirstOrderApp -> escapeArrowScope tc
-------------------------------------------
-- Command application
tc_cmd env cmd@(HsApp fun arg) (cmd_stk, res_ty)
= addErrCtxt (cmdCtxt cmd) $
-- gaw 2004 FIX?
- do { arg_ty <- newTyFlexiVarTy openTypeKind
+ do { arg_ty <- newFlexiTyVarTy openTypeKind
; fun' <- tcCmd env fun (arg_ty:cmd_stk, res_ty)
- ; arg' <- tcCheckRho arg arg_ty
+ ; arg' <- tcMonoExpr arg arg_ty
; return (HsApp fun' arg') }
(kappaUnderflow cmd)
-- Check the patterns, and the GRHSs inside
- ; (pats', grhss') <- setSrcSpan mtch_loc $
- tcMatchPats pats (map Check cmd_stk) (Check res_ty) $
+ ; (pats', grhss') <- setSrcSpan mtch_loc $
+ tcPats LamPat pats cmd_stk res_ty $
tc_grhss grhss
; let match' = L mtch_loc (Match pats' Nothing grhss')
n_pats = length pats
stk' = drop n_pats cmd_stk
match_ctxt = LambdaExpr -- Maybe KappaExpr?
+ pg_ctxt = PatGuard match_ctxt
- tc_grhss (GRHSs grhss binds)
- = tcBindsAndThen glueBindsOnGRHSs binds $
- do { grhss' <- mappM (wrapLocM tc_grhs) grhss
- ; return (GRHSs grhss' []) }
+ tc_grhss (GRHSs grhss binds) res_ty
+ = do { (binds', grhss') <- tcLocalBinds binds $
+ mapM (wrapLocM (tc_grhs res_ty)) grhss
+ ; return (GRHSs grhss' binds') }
- stmt_ctxt = SC { sc_what = PatGuard match_ctxt,
- sc_rhs = tcInferRho,
- sc_body = \ body -> tcCmd env body (stk', res_ty),
- sc_ty = res_ty } -- ToDo: Is this right?
- tc_grhs (GRHS guarded)
- = do { guarded' <- tcStmts stmt_ctxt guarded
- ; return (GRHS guarded') }
+ 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'))
+ ; return (GRHS guards' rhs') }
-------------------------------------------
-- Do notation
-tc_cmd env cmd@(HsDo do_or_lc stmts _ 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' <- tcStmts stmt_ctxt stmts
- ; return (HsDo do_or_lc stmts' [] res_ty) }
- -- The 'methods' needed for the HsDo are in the enclosing HsCmd
- -- hence the empty list here
+ ; (stmts', body') <- tcStmts do_or_lc tc_stmt stmts res_ty $ \ res_ty' ->
+ tcCmd env body ([], res_ty')
+ ; return (HsDo do_or_lc stmts' body' res_ty) }
where
- stmt_ctxt = SC { sc_what = do_or_lc,
- sc_rhs = tc_rhs,
- sc_body = tc_ret,
- sc_ty = res_ty }
-
- tc_rhs rhs = do { ty <- newTyFlexiVarTy liftedTypeKind
+ tc_stmt = tcMDoStmt tc_rhs
+ tc_rhs rhs = do { ty <- newFlexiTyVarTy liftedTypeKind
; rhs' <- tcCmd env rhs ([], ty)
; return (rhs', ty) }
- tc_ret body = tcCmd env body ([], res_ty)
-----------------------------------------------------------------
--- Arrow ``forms'' (| e |) c1 .. cn
+-- Arrow ``forms'' (| e c1 .. cn |)
--
-- G |-b c : [s1 .. sm] s
-- pop(G) |- e : forall w. b ((w,s1) .. sm) s
-- -> a ((w,t1) .. tn) t
-- e \not\in (s, s1..sm, t, t1..tn)
-- ----------------------------------------------
--- G |-a (| e |) c : [t1 .. tn] t
+-- G |-a (| e c |) : [t1 .. tn] t
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] <- tcSkolTyVars (ArrowSkol span) [alphaTyVar]
+ ; [w_tv] <- tcInstSkolTyVars (ArrowSkol span) [alphaTyVar]
; let w_ty = mkTyVarTy w_tv -- Just a convenient starting point
-- a ((w,t1) .. tn) t
e_res_ty
-- Check expr
- ; (expr', lie) <- getLIE (tcCheckRho expr e_ty)
+ ; (expr', lie) <- escapeArrowScope (getLIE (tcMonoExpr expr e_ty))
; inst_binds <- tcSimplifyCheck sig_msg [w_tv] [] lie
-- Check that the polymorphic variable hasn't been unified with anything
-- the s1..sm and check each cmd
; cmds' <- mapM (tc_cmd w_tv) cmds_w_tys
- ; returnM (HsArrForm (mkHsTyLam [w_tv] (mkHsLet inst_binds expr')) fixity cmds')
+ ; returnM (HsArrForm (mkHsTyLam [w_tv] (mkHsDictLet inst_binds expr')) fixity cmds')
}
where
-- Make the types
-> TcM (LHsCmdTop Name, Int, TcType, TcType, TcType)
new_cmd_ty cmd i
-- gaw 2004 FIX?
- = do { b_ty <- newTyFlexiVarTy arrowTyConKind
- ; tup_ty <- newTyFlexiVarTy liftedTypeKind
+ = do { b_ty <- newFlexiTyVarTy arrowTyConKind
+ ; tup_ty <- newFlexiTyVarTy liftedTypeKind
-- We actually make a type variable for the tuple
-- because we don't know how deeply nested it is yet
- ; s_ty <- newTyFlexiVarTy liftedTypeKind
+ ; s_ty <- newFlexiTyVarTy liftedTypeKind
; return (cmd, i, b_ty, tup_ty, s_ty)
}
not (w_tv `elemVarSet` tyVarsOfTypes arg_tys))
(badFormFun i tup_ty')
- ; tcCmdTop (CmdEnv { 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])
\begin{code}
mkPairTy t1 t2 = mkTyConApp pairTyCon [t1,t2]
-arrowTyConKind :: Kind -- *->*->*
+arrowTyConKind :: Kind -- *->*->*
arrowTyConKind = mkArrowKinds [liftedTypeKind, liftedTypeKind] liftedTypeKind
\end{code}
projects / ghc-hetmet.git / blobdiff