tcDoStmt, tcMDoStmt, tcGuardStmt
) where
-#include "HsVersions.h"
-
import {-# SOURCE #-} TcExpr( tcSyntaxOp, tcInferRho, tcMonoExpr, tcPolyExpr )
import HsSyn
import TcRnMonad
-import TcGadt
import Inst
import TcEnv
import TcPat
import Outputable
import Util
import SrcLoc
+import FastString
-import Control.Monad( liftM )
+import Control.Monad
\end{code}
%************************************************************************
tcMatches match_ctxt pat_tys rhs_ty matches
}
where
- doc = ptext SLIT("The equation(s) for") <+> quotes (ppr fun_name)
- <+> ptext SLIT("have") <+> speakNOf n_pats (ptext SLIT("argument"))
+ doc = ptext (sLit "The equation(s) for") <+> quotes (ppr fun_name)
+ <+> ptext (sLit "have") <+> speakNOf n_pats (ptext (sLit "argument"))
n_pats = matchGroupArity matches
match_ctxt = MC { mc_what = FunRhs fun_name inf, mc_body = tcBody }
\end{code}
tcMatches match_ctxt pat_tys rhs_ty match
where
n_pats = matchGroupArity match
- doc = sep [ ptext SLIT("The lambda expression")
+ doc = sep [ ptext (sLit "The lambda expression")
<+> quotes (pprSetDepth 1 $ pprMatches (LambdaExpr :: HsMatchContext Name) match),
-- The pprSetDepth makes the abstraction print briefly
- ptext SLIT("has") <+> speakNOf n_pats (ptext SLIT("argument"))]
+ ptext (sLit "has") <+> speakNOf n_pats (ptext (sLit "argument"))]
match_ctxt = MC { mc_what = LambdaExpr,
mc_body = tcBody }
\end{code}
\begin{code}
tcGRHSsPat :: GRHSs Name -> BoxyRhoType -> TcM (GRHSs TcId)
-- Used for pattern bindings
-tcGRHSsPat grhss res_ty = tcGRHSs match_ctxt grhss (emptyRefinement, res_ty)
- -- emptyRefinement: no refinement in a pattern binding
+tcGRHSsPat grhss res_ty = tcGRHSs match_ctxt grhss res_ty
where
match_ctxt = MC { mc_what = PatBindRhs,
mc_body = tcBody }
data TcMatchCtxt -- c.f. TcStmtCtxt, also in this module
= MC { mc_what :: HsMatchContext Name, -- What kind of thing this is
- mc_body :: LHsExpr Name -- Type checker for a body of an alternative
- -> (Refinement, BoxyRhoType)
+ mc_body :: LHsExpr Name -- Type checker for a body of
+ -- an alternative
+ -> BoxyRhoType
-> TcM (LHsExpr TcId) }
tcMatches ctxt pat_tys rhs_ty (MatchGroup matches _)
= tcGRHSs ctxt grhss rhs_ty -- No result signature
-- Result type sigs are no longer supported
- tc_grhss ctxt (Just res_sig) grhss (co, rhs_ty)
- = do { addErr (ptext SLIT("Ignoring (deprecated) result type signature")
+ tc_grhss ctxt (Just res_sig) grhss rhs_ty
+ = do { addErr (ptext (sLit "Ignoring (deprecated) result type signature")
<+> ppr res_sig)
- ; tcGRHSs ctxt grhss (co, rhs_ty) }
+ ; tcGRHSs ctxt grhss rhs_ty }
-- For (\x -> e), tcExpr has already said "In the expresssion \x->e"
-- so we don't want to add "In the lambda abstraction \x->e"
m_ctxt -> addErrCtxt (matchCtxt m_ctxt match) thing_inside
-------------
-tcGRHSs :: TcMatchCtxt -> GRHSs Name -> (Refinement, BoxyRhoType)
+tcGRHSs :: TcMatchCtxt -> GRHSs Name -> BoxyRhoType
-> TcM (GRHSs TcId)
-- Notice that we pass in the full res_ty, so that we get
tcGRHSs ctxt (GRHSs grhss binds) res_ty
= do { (binds', grhss') <- tcLocalBinds binds $
- mappM (wrapLocM (tcGRHS ctxt res_ty)) grhss
+ mapM (wrapLocM (tcGRHS ctxt res_ty)) grhss
- ; returnM (GRHSs grhss' binds') }
+ ; return (GRHSs grhss' binds') }
-------------
-tcGRHS :: TcMatchCtxt -> (Refinement, BoxyRhoType) -> GRHS Name -> TcM (GRHS TcId)
+tcGRHS :: TcMatchCtxt -> BoxyRhoType -> GRHS Name -> TcM (GRHS TcId)
tcGRHS ctxt res_ty (GRHS guards rhs)
= do { (guards', rhs') <- tcStmts stmt_ctxt tcGuardStmt guards res_ty $
tcDoStmts ListComp stmts body res_ty
= do { (elt_ty, coi) <- boxySplitListTy res_ty
; (stmts', body') <- tcStmts ListComp (tcLcStmt listTyCon) stmts
- (emptyRefinement,elt_ty) $
+ elt_ty $
tcBody body
; return $ mkHsWrapCoI coi
(HsDo ListComp stmts' body' (mkListTy elt_ty)) }
tcDoStmts PArrComp stmts body res_ty
= do { (elt_ty, coi) <- boxySplitPArrTy res_ty
; (stmts', body') <- tcStmts PArrComp (tcLcStmt parrTyCon) stmts
- (emptyRefinement, elt_ty) $
+ elt_ty $
tcBody body
; return $ mkHsWrapCoI coi
(HsDo PArrComp stmts' body' (mkPArrTy elt_ty)) }
tcDoStmts DoExpr stmts body res_ty
= do { (stmts', body') <- tcStmts DoExpr tcDoStmt stmts
- (emptyRefinement, res_ty) $
+ res_ty $
tcBody body
; return (HsDo DoExpr stmts' body' res_ty) }
tcMonoExpr rhs (mkAppTy m_ty pat_ty)
; (stmts', body') <- tcStmts ctxt (tcMDoStmt tc_rhs) stmts
- (emptyRefinement, res_ty') $
+ res_ty' $
tcBody body
; let names = [mfixName, bindMName, thenMName, returnMName, failMName]
tcDoStmts ctxt stmts body res_ty = pprPanic "tcDoStmts" (pprStmtContext ctxt)
-tcBody :: LHsExpr Name -> (Refinement, BoxyRhoType) -> TcM (LHsExpr TcId)
-tcBody body (reft, res_ty)
- = do { traceTc (text "tcBody" <+> ppr res_ty <+> ppr reft)
- ; let (co, res_ty') = refineResType reft res_ty
- ; body' <- tcPolyExpr body res_ty'
- ; return (mkLHsWrap co body') }
+tcBody :: LHsExpr Name -> BoxyRhoType -> TcM (LHsExpr TcId)
+tcBody body res_ty
+ = do { traceTc (text "tcBody" <+> ppr res_ty)
+ ; body' <- tcPolyExpr body res_ty
+ ; return body'
+ }
\end{code}
type TcStmtChecker
= forall thing. HsStmtContext Name
-> Stmt Name
- -> (Refinement, BoxyRhoType) -- Result type for comprehension
- -> ((Refinement,BoxyRhoType) -> TcM thing) -- Checker for what follows the stmt
+ -> BoxyRhoType -- Result type for comprehension
+ -> (BoxyRhoType -> TcM thing) -- Checker for what follows the stmt
-> TcM (Stmt TcId, thing)
- -- The incoming BoxyRhoType may be refined by type refinements
- -- before being passed to the thing_inside
-
tcStmts :: HsStmtContext Name
-> TcStmtChecker -- NB: higher-rank type
-> [LStmt Name]
- -> (Refinement, BoxyRhoType)
- -> ((Refinement, BoxyRhoType) -> TcM thing)
+ -> BoxyRhoType
+ -> (BoxyRhoType -> TcM thing)
-> TcM ([LStmt TcId], thing)
-- Note the higher-rank type. stmt_chk is applied at different
; return (ParStmt pairs', thing) }
where
-- loop :: [([LStmt Name], [Name])] -> TcM ([([LStmt TcId], [TcId])], thing)
- loop [] = do { thing <- thing_inside elt_ty -- No refinement from pattern
+ loop [] = do { thing <- thing_inside elt_ty
; return ([], thing) } -- matching in the branches
loop ((stmts, names) : pairs)
tcDoStmt :: TcStmtChecker
-tcDoStmt ctxt (BindStmt pat rhs bind_op fail_op) reft_res_ty@(_,res_ty) thing_inside
+tcDoStmt ctxt (BindStmt pat rhs bind_op fail_op) res_ty thing_inside
= do { (rhs', rhs_ty) <- tcInferRho rhs
- -- We should use type *inference* for the RHS computations, becuase of GADTs.
+ -- We should use type *inference* for the RHS computations,
+ -- becuase of GADTs.
-- do { pat <- rhs; <rest> }
-- is rather like
-- case rhs of { pat -> <rest> }
- -- We do inference on rhs, so that information about its type can be refined
- -- when type-checking the pattern.
-
- -- Deal with rebindable syntax; (>>=) :: rhs_ty -> (a -> res_ty) -> res_ty
- ; (bind_op', pat_ty) <-
+ -- We do inference on rhs, so that information about its type
+ -- can be refined when type-checking the pattern.
+
+ -- Deal with rebindable syntax:
+ -- (>>=) :: rhs_ty -> (pat_ty -> new_res_ty) -> res_ty
+ -- This level of generality is needed for using do-notation
+ -- in full generality; see Trac #1537
+ ; ((bind_op', new_res_ty), pat_ty) <-
withBox liftedTypeKind $ \ pat_ty ->
+ withBox liftedTypeKind $ \ new_res_ty ->
tcSyntaxOp DoOrigin bind_op
- (mkFunTys [rhs_ty, mkFunTy pat_ty res_ty] res_ty)
+ (mkFunTys [rhs_ty, mkFunTy pat_ty new_res_ty] res_ty)
-- If (but only if) the pattern can fail,
-- typecheck the 'fail' operator
; fail_op' <- if isIrrefutableHsPat pat
then return noSyntaxExpr
- else tcSyntaxOp DoOrigin fail_op (mkFunTy stringTy res_ty)
+ else tcSyntaxOp DoOrigin fail_op (mkFunTy stringTy new_res_ty)
- ; (pat', thing) <- tcLamPat pat pat_ty reft_res_ty thing_inside
+ ; (pat', thing) <- tcLamPat pat pat_ty new_res_ty thing_inside
; return (BindStmt pat' rhs' bind_op' fail_op', thing) }
-tcDoStmt ctxt (ExprStmt rhs then_op _) reft_res_ty@(_,res_ty) thing_inside
+tcDoStmt ctxt (ExprStmt rhs then_op _) res_ty thing_inside
= do { (rhs', rhs_ty) <- tcInferRho rhs
- -- Deal with rebindable syntax; (>>) :: rhs_ty -> res_ty -> res_ty
- ; then_op' <- tcSyntaxOp DoOrigin then_op
- (mkFunTys [rhs_ty, res_ty] res_ty)
+ -- Deal with rebindable syntax; (>>) :: rhs_ty -> new_res_ty -> res_ty
+ ; (then_op', new_res_ty) <-
+ withBox liftedTypeKind $ \ new_res_ty ->
+ tcSyntaxOp DoOrigin then_op
+ (mkFunTys [rhs_ty, new_res_ty] res_ty)
- ; thing <- thing_inside reft_res_ty
+ ; thing <- thing_inside new_res_ty
; return (ExprStmt rhs' then_op' rhs_ty, thing) }
+tcDoStmt ctxt (RecStmt {}) res_ty thing_inside
+ = failWithTc (ptext (sLit "Illegal 'rec' stmt in") <+> pprStmtContext ctxt)
+ -- This case can't be caught in the renamer
+ -- see RnExpr.checkRecStmt
+
tcDoStmt ctxt stmt res_ty thing_inside
= pprPanic "tcDoStmt: unexpected Stmt" (ppr stmt)
checkArgs fun (MatchGroup (match1:matches) _)
| null bad_matches = return ()
| otherwise
- = failWithTc (vcat [ptext SLIT("Equations for") <+> quotes (ppr fun) <+>
- ptext SLIT("have different numbers of arguments"),
+ = failWithTc (vcat [ptext (sLit "Equations for") <+> quotes (ppr fun) <+>
+ ptext (sLit "have different numbers of arguments"),
nest 2 (ppr (getLoc match1)),
nest 2 (ppr (getLoc (head bad_matches)))])
where
\end{code}
\begin{code}
-matchCtxt ctxt match = hang (ptext SLIT("In") <+> pprMatchContext ctxt <> colon)
+matchCtxt ctxt match = hang (ptext (sLit "In") <+> pprMatchContext ctxt <> colon)
4 (pprMatch ctxt match)
-stmtCtxt ctxt stmt = hang (ptext SLIT("In") <+> pprStmtContext ctxt <> colon)
+stmtCtxt ctxt stmt = hang (ptext (sLit "In a stmt of") <+> pprStmtContext ctxt <> colon)
4 (ppr stmt)
\end{code}
projects / ghc-hetmet.git / blobdiff