module Agda.TypeChecking.Constraints where
import Control.Monad.State
import Control.Monad.Reader
import Control.Applicative
import Data.List as List
import Agda.Syntax.Internal
import Agda.TypeChecking.Monad
import Agda.TypeChecking.InstanceArguments
import Agda.TypeChecking.Pretty
import Agda.TypeChecking.Reduce
import Agda.TypeChecking.Substitute
import Agda.TypeChecking.LevelConstraints
import Agda.TypeChecking.SizedTypes
import Agda.TypeChecking.Rules.Term
import Agda.TypeChecking.Conversion
import Agda.TypeChecking.MetaVars
import Agda.TypeChecking.Empty
import Agda.Utils.Except ( MonadError(throwError) )
import Agda.Utils.Maybe
import Agda.Utils.Monad
import Agda.Utils.Pretty (prettyShow)
import Agda.Utils.Lens
#include "undefined.h"
import Agda.Utils.Impossible
catchConstraint :: Constraint -> TCM () -> TCM ()
catchConstraint c v = liftTCM $
catchError_ v $ \err ->
case err of
PatternErr{} -> addConstraint c
_ -> throwError err
addConstraint :: Constraint -> TCM ()
addConstraint c = do
pids <- asks envActiveProblems
reportSDoc "tc.constr.add" 20 $ hsep
[ text "adding constraint"
, text (show pids)
, prettyTCM c ]
c <- reduce =<< instantiateFull c
c' <- simpl c
if (c /= c')
then do
reportSDoc "tc.constr.add" 20 $ text " simplified:" <+> prettyTCM c'
solveConstraint_ c'
else addConstraint' c'
unless (isIFSConstraint c) $
wakeConstraints (isWakeableIFSConstraint . clValue . theConstraint)
where
isWakeableIFSConstraint :: Constraint -> TCM Bool
isWakeableIFSConstraint (FindInScope _ b _) = caseMaybe b (return True) (\m -> isInstantiatedMeta m)
isWakeableIFSConstraint _ = return False
isIFSConstraint :: Constraint -> Bool
isIFSConstraint FindInScope{} = True
isIFSConstraint _ = False
simpl :: Constraint -> TCM Constraint
simpl c = do
n <- genericLength <$> getContext
let isLvl LevelCmp{} = True
isLvl _ = False
cs <- getAllConstraints
lvls <- instantiateFull $ List.filter (isLvl . clValue . theConstraint) cs
when (not $ List.null lvls) $ reportSDoc "tc.constr.add" 40 $ text " simplifying using" <+> prettyTCM lvls
return $ simplifyLevelConstraint n c lvls
noConstraints :: TCM a -> TCM a
noConstraints problem = liftTCM $ do
(pid, x) <- newProblem problem
cs <- getConstraintsForProblem pid
unless (List.null cs) $ typeError $ UnsolvedConstraints cs
return x
newProblem :: TCM a -> TCM (ProblemId, a)
newProblem action = do
pid <- fresh
x <- nowSolvingConstraints $ solvingProblem pid action
solveAwakeConstraints
return (pid, x)
newProblem_ :: TCM () -> TCM ProblemId
newProblem_ action = fst <$> newProblem action
ifNoConstraints :: TCM a -> (a -> TCM b) -> (ProblemId -> a -> TCM b) -> TCM b
ifNoConstraints check ifNo ifCs = do
(pid, x) <- newProblem check
ifM (isProblemSolved pid) (ifNo x) (ifCs pid x)
ifNoConstraints_ :: TCM () -> TCM a -> (ProblemId -> TCM a) -> TCM a
ifNoConstraints_ check ifNo ifCs = ifNoConstraints check (const ifNo) (\pid _ -> ifCs pid)
guardConstraint :: Constraint -> TCM () -> TCM ()
guardConstraint c blocker =
ifNoConstraints_ blocker (solveConstraint_ c) (addConstraint . Guarded c)
whenConstraints :: TCM () -> TCM () -> TCM ()
whenConstraints action handler =
ifNoConstraints_ action (return ()) $ \pid -> do
stealConstraints pid
handler
wakeupConstraints :: MetaId -> TCM ()
wakeupConstraints x = do
wakeConstraints (return . const True)
solveAwakeConstraints
wakeupConstraints_ :: TCM ()
wakeupConstraints_ = do
wakeConstraints (return . const True)
solveAwakeConstraints
solveAwakeConstraints :: TCM ()
solveAwakeConstraints = solveAwakeConstraints' False
solveAwakeConstraints' :: Bool -> TCM ()
solveAwakeConstraints' force = do
verboseS "profile.constraints" 10 $ liftTCM $ tickMax "max-open-constraints" . genericLength =<< getAllConstraints
whenM ((force ||) . not <$> isSolvingConstraints) $ nowSolvingConstraints $ do
solve
where
solve = do
reportSDoc "tc.constr.solve" 10 $ hsep [ text "Solving awake constraints."
, text . show . length =<< getAwakeConstraints
, text "remaining." ]
whenJustM takeAwakeConstraint $ \ c -> do
withConstraint solveConstraint c
solve
solveConstraint :: Constraint -> TCM ()
solveConstraint c = do
verboseS "profile.constraints" 10 $ liftTCM $ tick "attempted-constraints"
verboseBracket "tc.constr.solve" 20 "solving constraint" $ do
pids <- asks envActiveProblems
reportSDoc "tc.constr.solve" 20 $ text (show pids) <+> prettyTCM c
solveConstraint_ c
solveConstraint_ :: Constraint -> TCM ()
solveConstraint_ (ValueCmp cmp a u v) = compareTerm cmp a u v
solveConstraint_ (ElimCmp cmp a e u v) = compareElims cmp a e u v
solveConstraint_ (TypeCmp cmp a b) = compareType cmp a b
solveConstraint_ (TelCmp a b cmp tela telb) = compareTel a b cmp tela telb
solveConstraint_ (SortCmp cmp s1 s2) = compareSort cmp s1 s2
solveConstraint_ (LevelCmp cmp a b) = compareLevel cmp a b
solveConstraint_ c0@(Guarded c pid) = do
ifM (isProblemSolved pid) (solveConstraint_ c)
(addConstraint c0)
solveConstraint_ (IsEmpty r t) = isEmptyType r t
solveConstraint_ (CheckSizeLtSat t) = checkSizeLtSat t
solveConstraint_ (UnBlock m) =
ifM (isFrozen m) (addConstraint $ UnBlock m) $ do
inst <- mvInstantiation <$> lookupMeta m
reportSDoc "tc.constr.unblock" 15 $ text ("unblocking a metavar yields the constraint: " ++ show inst)
case inst of
BlockedConst t -> do
reportSDoc "tc.constr.blocked" 15 $
text ("blocked const " ++ prettyShow m ++ " :=") <+> prettyTCM t
assignTerm m [] t
PostponedTypeCheckingProblem cl unblock -> enterClosure cl $ \prob -> do
ifNotM unblock (addConstraint $ UnBlock m) $ do
tel <- getContextTelescope
v <- liftTCM $ checkTypeCheckingProblem prob
assignTerm m (telToArgs tel) v
InstV{} -> return ()
InstS{} -> return ()
Open -> __IMPOSSIBLE__
OpenIFS -> __IMPOSSIBLE__
solveConstraint_ (FindInScope m b cands) = findInScope m cands
checkTypeCheckingProblem :: TypeCheckingProblem -> TCM Term
checkTypeCheckingProblem p = case p of
CheckExpr e t -> checkExpr e t
CheckArgs eh r args t0 t1 k -> checkArguments' eh r args t0 t1 k
CheckLambda args body target -> checkPostponedLambda args body target
UnquoteTactic tac hole t -> unquoteTactic tac hole t $ return hole
debugConstraints :: TCM ()
debugConstraints = verboseS "tc.constr" 50 $ do
awake <- use stAwakeConstraints
sleeping <- use stSleepingConstraints
reportSDoc "" 0 $ vcat
[ text "Current constraints"
, nest 2 $ vcat [ text "awake " <+> vcat (map prettyTCM awake)
, text "asleep" <+> vcat (map prettyTCM sleeping) ] ]