CanonicalCt(..), Xi, tyVarsOfCanonical, tyVarsOfCanonicals, tyVarsOfCDicts,
deCanonicalise, mkFrozenError,
- makeSolvedByInst,
isWanted, isGiven, isDerived,
isGivenCt, isWantedCt, isDerivedCt, pprFlavorArising,
combineCtLoc, mkGivenFlavor, mkWantedFlavor,
getWantedLoc,
- TcS, runTcS, failTcS, panicTcS, traceTcS, traceTcS0, -- Basic functionality
+ TcS, runTcS, failTcS, panicTcS, traceTcS, -- Basic functionality
+ traceFireTcS, bumpStepCountTcS,
tryTcS, nestImplicTcS, recoverTcS, wrapErrTcS, wrapWarnTcS,
SimplContext(..), isInteractive, simplEqsOnly, performDefaulting,
instDFunTypes, -- Instantiation
instDFunConstraints,
- newFlexiTcSTy,
+ newFlexiTcSTy, instFlexiTcS,
compatKind,
matchClass, matchFam, MatchInstResult (..),
checkWellStagedDFun,
warnTcS,
- pprEq, -- Smaller utils, re-exported from TcM
+ pprEq -- Smaller utils, re-exported from TcM
-- TODO (DV): these are only really used in the
-- instance matcher in TcSimplify. I am wondering
-- if the whole instance matcher simply belongs
-- here
-
-
- mkDerivedFunDepEqns -- Instantiation of 'Equations' from FunDeps
-
) where
#include "HsVersions.h"
import HsBinds -- for TcEvBinds stuff
import Id
-import FunDeps
import TcRnTypes
compatKind :: Kind -> Kind -> Bool
compatKind k1 k2 = k1 `isSubKind` k2 || k2 `isSubKind` k1
-makeSolvedByInst :: CanonicalCt -> CanonicalCt
--- Record that a constraint is now solved
--- Wanted -> Given
--- Given, Derived -> no-op
-makeSolvedByInst ct
- | Wanted loc <- cc_flavor ct
- = ct { cc_flavor = Given (setCtLocOrigin loc UnkSkol) }
- | otherwise -- Only called on wanteds
- = pprPanic "makeSolvedByInst" (ppr ct)
-
deCanonicalise :: CanonicalCt -> FlavoredEvVar
deCanonicalise ct = mkEvVarX (cc_id ct) (cc_flavor ct)
tcs_context :: SimplContext,
- tcs_untch :: TcsUntouchables
+ tcs_untch :: TcsUntouchables,
+
+ tcs_ic_depth :: Int, -- Implication nesting depth
+ tcs_count :: IORef Int -- Global step count
}
type TcsUntouchables = (Untouchables,TcTyVarSet)
traceTcS :: String -> SDoc -> TcS ()
traceTcS herald doc = TcS $ \_env -> TcM.traceTc herald doc
-traceTcS0 :: String -> SDoc -> TcS ()
-traceTcS0 herald doc = TcS $ \_env -> TcM.traceTcN 0 herald doc
+bumpStepCountTcS :: TcS ()
+bumpStepCountTcS = TcS $ \env -> do { let ref = tcs_count env
+ ; n <- TcM.readTcRef ref
+ ; TcM.writeTcRef ref (n+1) }
+
+traceFireTcS :: Int -> SDoc -> TcS ()
+-- Dump a rule-firing trace
+traceFireTcS depth doc
+ = TcS $ \env ->
+ TcM.ifDOptM Opt_D_dump_cs_trace $
+ do { n <- TcM.readTcRef (tcs_count env)
+ ; let msg = int n
+ <> text (replicate (tcs_ic_depth env) '>')
+ <> brackets (int depth) <+> doc
+ ; TcM.dumpTcRn msg }
runTcS :: SimplContext
-> Untouchables -- Untouchables
runTcS context untouch tcs
= do { ty_binds_var <- TcM.newTcRef emptyVarEnv
; ev_binds_var@(EvBindsVar evb_ref _) <- TcM.newTcEvBinds
+ ; step_count <- TcM.newTcRef 0
; let env = TcSEnv { tcs_ev_binds = ev_binds_var
, tcs_ty_binds = ty_binds_var
, tcs_context = context
, tcs_untch = (untouch, emptyVarSet) -- No Tcs untouchables yet
+ , tcs_count = step_count
+ , tcs_ic_depth = 0
}
-- Run the computation
; ty_binds <- TcM.readTcRef ty_binds_var
; mapM_ do_unification (varEnvElts ty_binds)
+#ifdef DEBUG
+ ; count <- TcM.readTcRef step_count
+ ; TcM.dumpTcRn (ptext (sLit "Constraint solver steps =") <+> int count)
+#endif
-- And return
; ev_binds <- TcM.readTcRef evb_ref
; return (res, evBindMapBinds ev_binds) }
do_unification (tv,ty) = TcM.writeMetaTyVar tv ty
nestImplicTcS :: EvBindsVar -> TcsUntouchables -> TcS a -> TcS a
-nestImplicTcS ref untch (TcS thing_inside)
- = TcS $ \ TcSEnv { tcs_ty_binds = ty_binds,
- tcs_context = ctxt } ->
+nestImplicTcS ref (inner_range, inner_tcs) (TcS thing_inside)
+ = TcS $ \ TcSEnv { tcs_ty_binds = ty_binds
+ , tcs_untch = (_outer_range, outer_tcs)
+ , tcs_count = count
+ , tcs_ic_depth = idepth
+ , tcs_context = ctxt } ->
let
+ inner_untch = (inner_range, outer_tcs `unionVarSet` inner_tcs)
+ -- The inner_range should be narrower than the outer one
+ -- (thus increasing the set of untouchables) but
+ -- the inner Tcs-untouchables must be unioned with the
+ -- outer ones!
nest_env = TcSEnv { tcs_ev_binds = ref
, tcs_ty_binds = ty_binds
- , tcs_untch = untch
+ , tcs_untch = inner_untch
+ , tcs_count = count
+ , tcs_ic_depth = idepth+1
, tcs_context = ctxtUnderImplic ctxt }
in
thing_inside nest_env
-- DV: We never return MatchInstMany, since tcLookupFamInst never returns
-- multiple matches. Check.
}
-
-
--- Functional dependencies, instantiation of equations
--------------------------------------------------------
-
-mkDerivedFunDepEqns :: WantedLoc
- -> [(Equation, (PredType, SDoc), (PredType, SDoc))]
- -> TcS [FlavoredEvVar] -- All Derived
-mkDerivedFunDepEqns _ [] = return []
-mkDerivedFunDepEqns loc eqns
- = do { traceTcS "Improve:" (vcat (map pprEquationDoc eqns))
- ; evvars <- mapM to_work_item eqns
- ; return $ concat evvars }
- where
- to_work_item :: (Equation, (PredType,SDoc), (PredType,SDoc)) -> TcS [FlavoredEvVar]
- to_work_item ((qtvs, pairs), d1, d2)
- = do { let tvs = varSetElems qtvs
- ; tvs' <- mapM instFlexiTcS tvs
- ; let subst = zipTopTvSubst tvs (mkTyVarTys tvs')
- loc' = pushErrCtxt FunDepOrigin (False, mkEqnMsg d1 d2) loc
- flav = Derived loc'
- ; mapM (do_one subst flav) pairs }
-
- do_one subst flav (ty1, ty2)
- = do { let sty1 = substTy subst ty1
- sty2 = substTy subst ty2
- ; ev <- newCoVar sty1 sty2
- ; return (mkEvVarX ev flav) }
-
-pprEquationDoc :: (Equation, (PredType, SDoc), (PredType, SDoc)) -> SDoc
-pprEquationDoc (eqn, (p1, _), (p2, _))
- = vcat [pprEquation eqn, nest 2 (ppr p1), nest 2 (ppr p2)]
-
-mkEqnMsg :: (TcPredType, SDoc) -> (TcPredType, SDoc) -> TidyEnv
- -> TcM (TidyEnv, SDoc)
-mkEqnMsg (pred1,from1) (pred2,from2) tidy_env
- = do { pred1' <- TcM.zonkTcPredType pred1
- ; pred2' <- TcM.zonkTcPredType pred2
- ; let { pred1'' = tidyPred tidy_env pred1'
- ; pred2'' = tidyPred tidy_env pred2' }
- ; let msg = vcat [ptext (sLit "When using functional dependencies to combine"),
- nest 2 (sep [ppr pred1'' <> comma, nest 2 from1]),
- nest 2 (sep [ppr pred2'' <> comma, nest 2 from2])]
- ; return (tidy_env, msg) }
\end{code}
projects / ghc-hetmet.git / blobdiff