{-# LANGUAGE PatternGuards #-} module Idris.Elab.Clause where import Idris.AbsSyntax import Idris.ASTUtils import Idris.DSL import Idris.Error import Idris.Delaborate import Idris.Imports import Idris.Elab.Term import Idris.Coverage import Idris.DataOpts import Idris.Providers import Idris.Primitives import Idris.Inliner import Idris.PartialEval import Idris.Transforms import Idris.DeepSeq import Idris.Output (iputStrLn, pshow, iWarn, iRenderResult, sendHighlighting) import IRTS.Lang import Idris.Elab.AsPat import Idris.Elab.Type import Idris.Elab.Transform import Idris.Elab.Utils import Idris.Core.TT import Idris.Core.Elaborate hiding (Tactic(..)) import Idris.Core.Evaluate import Idris.Core.Execute import Idris.Core.Typecheck import Idris.Core.CaseTree import Idris.Docstrings hiding (Unchecked) import Util.Pretty hiding ((<$>)) import Prelude hiding (id, (.)) import Control.Category import Control.Applicative hiding (Const) import Control.DeepSeq import Control.Monad import Control.Monad.State.Strict as State import qualified Control.Monad.State.Lazy as LState import Data.List import Data.Maybe import Debug.Trace import qualified Data.Map as Map import qualified Data.Set as S import qualified Data.Text as T import Data.Char(isLetter, toLower) import Data.List.Split (splitOn) import Util.Pretty(pretty, text) import Numeric -- | Elaborate a collection of left-hand and right-hand pairs - that is, a -- top-level definition. elabClauses :: ElabInfo -> FC -> FnOpts -> Name -> [PClause] -> Idris () elabClauses info' fc opts n_in cs = do let n = liftname info n_in info = info' { elabFC = Just fc } ctxt <- getContext ist <- getIState optimise <- getOptimise let petrans = PETransform `elem` optimise inacc <- map fst <$> fgetState (opt_inaccessible . ist_optimisation n) -- Check n actually exists, with no definition yet let tys = lookupTy n ctxt let reflect = Reflection `elem` opts checkUndefined n ctxt unless (length tys > 1) $ do fty <- case tys of [] -> -- TODO: turn into a CAF if there's no arguments -- question: CAFs in where blocks? tclift $ tfail $ At fc (NoTypeDecl n) [ty] -> return ty let atys = map snd (getArgTys fty) cs_elab <- mapM (elabClause info opts) (zip [0..] cs) ctxt <- getContext -- pats_raw is the version we'll work with at compile time: -- no simplification or PE let (pats_in, cs_full) = unzip cs_elab let pats_raw = map (simple_lhs ctxt) pats_in logElab 3 $ "Elaborated patterns:\n" ++ show pats_raw solveDeferred fc n -- just ensure that the structure exists fmodifyState (ist_optimisation n) id addIBC (IBCOpt n) ist <- getIState ctxt <- getContext -- Don't apply rules if this is a partial evaluation definition, -- or we'll make something that just runs itself! let tpats = case specNames opts of Nothing -> transformPats ist pats_in _ -> pats_in -- If the definition is specialisable, this reduces the -- RHS pe_tm <- doPartialEval ist tpats let pats_pe = if petrans then map (simple_lhs ctxt) pe_tm else pats_raw let tcase = opt_typecase (idris_options ist) -- Look for 'static' names and generate new specialised -- definitions for them, as well as generating rewrite rules -- for partially evaluated definitions newrules <- if petrans then mapM (\ e -> case e of Left _ -> return [] Right (l, r) -> elabPE info fc n r) pats_pe else return [] -- Redo transforms with the newly generated transformations, so -- that the specialised application we've just made gets -- used in place of the general one ist <- getIState let pats_transformed = if petrans then transformPats ist pats_pe else pats_pe -- Summary of what's about to happen: Definitions go: -- -- pats_in -> pats -> pdef -> pdef' -- addCaseDef builds case trees from and -- pdef is the compile-time pattern definition. -- This will get further inlined to help with totality checking. let pdef = map (\(ns, lhs, rhs) -> (map fst ns, lhs, rhs)) $ map debind pats_raw -- pdef_pe is the one which will get further optimised -- for run-time, and, partially evaluated let pdef_pe = map debind pats_transformed logElab 5 $ "Initial typechecked patterns:\n" ++ show pats_raw logElab 5 $ "Initial typechecked pattern def:\n" ++ show pdef -- NOTE: Need to store original definition so that proofs which -- rely on its structure aren't affected by any changes to the -- inliner. Just use the inlined version to generate pdef' and to -- help with later inlinings. ist <- getIState let pdef_inl = inlineDef ist pdef numArgs <- tclift $ sameLength pdef case specNames opts of Just _ -> do logElab 3 $ "Partially evaluated:\n" ++ show pats_pe _ -> return () logElab 3 $ "Transformed:\n" ++ show pats_transformed erInfo <- getErasureInfo <$> getIState tree@(CaseDef scargs sc _) <- tclift $ simpleCase tcase (UnmatchedCase "Error") reflect CompileTime fc inacc atys pdef erInfo cov <- coverage pmissing <- if cov && not (hasDefault pats_raw) then do -- Generate clauses from the given possible cases missing <- genClauses fc n (map getLHS pdef) cs_full -- missing <- genMissing n scargs sc missing' <- filterM (checkPossible info fc True n) missing -- Filter out the ones which match one of the -- given cases (including impossible ones) let clhs = map getLHS pdef logElab 2 $ "Must be unreachable:\n" ++ showSep "\n" (map showTmImpls missing') ++ "\nAgainst: " ++ showSep "\n" (map (\t -> showTmImpls (delab ist t)) (map getLHS pdef)) -- filter out anything in missing' which is -- matched by any of clhs. This might happen since -- unification may force a variable to take a -- particular form, rather than force a case -- to be impossible. return (filter (noMatch ist clhs) missing') else return [] let pcover = null pmissing -- pdef' is the version that gets compiled for run-time, -- so we start from the partially evaluated version pdef_in' <- applyOpts $ map (\(ns, lhs, rhs) -> (map fst ns, lhs, rhs)) pdef_pe ctxt <- getContext let pdef' = map (simple_rt ctxt) pdef_in' logElab 5 $ "After data structure transformations:\n" ++ show pdef' ist <- getIState let tot | pcover = Unchecked -- finish later | AssertTotal `elem` opts = Total [] | PEGenerated `elem` opts = Generated | otherwise = Partial NotCovering -- already know it's not total case tree of CaseDef _ _ [] -> return () CaseDef _ _ xs -> mapM_ (\x -> iputStrLn $ show fc ++ ":warning - Unreachable case: " ++ show (delab ist x)) xs let knowncovering = (pcover && cov) || AssertTotal `elem` opts let defaultcase = if knowncovering then STerm Erased else UnmatchedCase $ "*** " ++ show fc ++ ":unmatched case in " ++ show n ++ " ***" tree' <- tclift $ simpleCase tcase defaultcase reflect RunTime fc inacc atys pdef' erInfo logElab 3 $ "Unoptimised " ++ show n ++ ": " ++ show tree logElab 3 $ "Optimised: " ++ show tree' ctxt <- getContext ist <- getIState let opt = idris_optimisation ist putIState (ist { idris_patdefs = addDef n (force pdef_pe, force pmissing) (idris_patdefs ist) }) let caseInfo = CaseInfo (inlinable opts) (inlinable opts) (dictionary opts) case lookupTyExact n ctxt of Just ty -> do ctxt' <- do ctxt <- getContext tclift $ addCasedef n erInfo caseInfo tcase defaultcase reflect (AssertTotal `elem` opts) atys inacc pats_pe pdef pdef -- compile time pdef_inl -- inlined pdef' ty ctxt setContext ctxt' addIBC (IBCDef n) addDefinedName n setTotality n tot when (not reflect && PEGenerated `notElem` opts) $ do totcheck (fc, n) defer_totcheck (fc, n) when (tot /= Unchecked) $ addIBC (IBCTotal n tot) i <- getIState ctxt <- getContext case lookupDef n ctxt of (CaseOp _ _ _ _ _ cd : _) -> let (scargs, sc) = cases_compiletime cd in do let calls = map fst $ findCalls sc scargs -- let scg = buildSCG i sc scargs -- add SCG later, when checking totality logElab 2 $ "Called names: " ++ show calls -- if the definition is public, make sure -- it only uses public names nvis <- getFromHideList n case nvis of Just Public -> mapM_ (checkVisibility fc n Public Public) calls _ -> return () addCalls n calls addIBC (IBCCG n) _ -> return () return () -- addIBC (IBCTotal n tot) _ -> return () -- Check it's covering, if 'covering' option is used. Chase -- all called functions, and fail if any of them are also -- 'Partial NotCovering' when (CoveringFn `elem` opts) $ checkAllCovering fc [] n n where noMatch i cs tm = all (\x -> case trim_matchClause i (delab' i x True True) tm of Right _ -> False Left miss -> True) cs where trim_matchClause i (PApp fcl fl ls) (PApp fcr fr rs) = let args = min (length ls) (length rs) in matchClause i (PApp fcl fl (take args ls)) (PApp fcr fr (take args rs)) checkUndefined n ctxt = case lookupDef n ctxt of [] -> return () [TyDecl _ _] -> return () _ -> tclift $ tfail (At fc (AlreadyDefined n)) debind (Right (x, y)) = let (vs, x') = depat [] x (_, y') = depat [] y in (vs, x', y') debind (Left x) = let (vs, x') = depat [] x in (vs, x', Impossible) depat acc (Bind n (PVar t) sc) = depat ((n, t) : acc) (instantiate (P Bound n t) sc) depat acc x = (acc, x) getPVs (Bind x (PVar _) tm) = let (vs, tm') = getPVs tm in (x:vs, tm') getPVs tm = ([], tm) isPatVar vs (P Bound n _) = n `elem` vs isPatVar _ _ = False hasDefault cs | (Right (lhs, rhs) : _) <- reverse cs , (pvs, tm) <- getPVs (explicitNames lhs) , (f, args) <- unApply tm = all (isPatVar pvs) args hasDefault _ = False getLHS (_, l, _) = l -- Simplify the left hand side of a definition, to remove any lets -- that may have arisen during elaboration simple_lhs ctxt (Right (x, y)) = Right (Idris.Core.Evaluate.simplify ctxt [] x, y) simple_lhs ctxt t = t simple_rt ctxt (p, x, y) = (p, x, force (uniqueBinders p (rt_simplify ctxt [] y))) specNames [] = Nothing specNames (Specialise ns : _) = Just ns specNames (_ : xs) = specNames xs sameLength ((_, x, _) : xs) = do l <- sameLength xs let (f, as) = unApply x if (null xs || l == length as) then return (length as) else tfail (At fc (Msg "Clauses have differing numbers of arguments ")) sameLength [] = return 0 -- Partially evaluate, if the definition is marked as specialisable doPartialEval ist pats = case specNames opts of Nothing -> return pats Just ns -> case partial_eval (tt_ctxt ist) ns pats of Just t -> return t Nothing -> ierror (At fc (Msg "No specialisation achieved")) -- | Find 'static' applications in a term and partially evaluate them. -- Return any new transformation rules elabPE :: ElabInfo -> FC -> Name -> Term -> Idris [(Term, Term)] elabPE info fc caller r = do ist <- getIState let sa = filter (\ap -> fst ap /= caller) $ getSpecApps ist [] r rules <- mapM mkSpecialised sa return $ concat rules where -- Make a specialised version of the application, and -- add a PTerm level transformation rule, which is basically the -- new definition in reverse (before specialising it). -- RHS => LHS where implicit arguments are left blank in the -- transformation. -- Transformation rules are applied after every PClause elaboration mkSpecialised :: (Name, [(PEArgType, Term)]) -> Idris [(Term, Term)] mkSpecialised specapp_in = do ist <- getIState ctxt <- getContext let (specTy, specapp) = getSpecTy ist specapp_in let (n, newnm, specdecl) = getSpecClause ist specapp let lhs = pe_app specdecl let rhs = pe_def specdecl let undef = case lookupDefExact newnm ctxt of Nothing -> True _ -> False logElab 5 $ show (newnm, undef, map (concreteArg ist) (snd specapp)) idrisCatch (if (undef && all (concreteArg ist) (snd specapp)) then do cgns <- getAllNames n -- on the RHS of the new definition, we should reduce -- everything that's not itself static (because we'll -- want to be a PE version of those next) let cgns' = filter (\x -> x /= n && notStatic ist x) cgns -- set small reduction limit on partial/productive things let maxred = case lookupTotal n ctxt of [Total _] -> 65536 [Productive] -> 16 _ -> 1 let opts = [Specialise ((if pe_simple specdecl then map (\x -> (x, Nothing)) cgns' else []) ++ (n, Just maxred) : mapMaybe (specName (pe_simple specdecl)) (snd specapp))] logElab 3 $ "Specialising application: " ++ show specapp ++ " in " ++ show caller ++ " with " ++ show opts logElab 3 $ "New name: " ++ show newnm logElab 3 $ "PE definition type : " ++ (show specTy) ++ "\n" ++ show opts logElab 3 $ "PE definition " ++ show newnm ++ ":\n" ++ showSep "\n" (map (\ (lhs, rhs) -> (showTmImpls lhs ++ " = " ++ showTmImpls rhs)) (pe_clauses specdecl)) logElab 2 $ show n ++ " transformation rule: " ++ showTmImpls rhs ++ " ==> " ++ showTmImpls lhs elabType info defaultSyntax emptyDocstring [] fc opts newnm NoFC specTy let def = map (\(lhs, rhs) -> let lhs' = mapPT hiddenToPH $ stripUnmatchable ist lhs in PClause fc newnm lhs' [] rhs []) (pe_clauses specdecl) trans <- elabTransform info fc False rhs lhs elabClauses info fc (PEGenerated:opts) newnm def return [trans] else return []) -- if it doesn't work, just don't specialise. Could happen for lots -- of valid reasons (e.g. local variables in scope which can't be -- lifted out). (\e -> do logElab 3 $ "Couldn't specialise: " ++ (pshow ist e) return []) hiddenToPH (PHidden _) = Placeholder hiddenToPH x = x specName simpl (ImplicitS, tm) | (P Ref n _, _) <- unApply tm = Just (n, Just (if simpl then 1 else 0)) specName simpl (ExplicitS, tm) | (P Ref n _, _) <- unApply tm = Just (n, Just (if simpl then 1 else 0)) specName simpl _ = Nothing notStatic ist n = case lookupCtxtExact n (idris_statics ist) of Just s -> not (or s) _ -> True concreteArg ist (ImplicitS, tm) = concreteTm ist tm concreteArg ist (ExplicitS, tm) = concreteTm ist tm concreteArg ist _ = True concreteTm ist tm | (P _ n _, _) <- unApply tm = case lookupTy n (tt_ctxt ist) of [] -> False _ -> True concreteTm ist (Constant _) = True concreteTm ist (Bind n (Lam _) sc) = True concreteTm ist (Bind n (Pi _ _ _) sc) = True concreteTm ist (Bind n (Let _ _) sc) = concreteTm ist sc concreteTm ist _ = False -- get the type of a specialised application getSpecTy ist (n, args) = case lookupTy n (tt_ctxt ist) of [ty] -> let (specty_in, args') = specType args (explicitNames ty) specty = normalise (tt_ctxt ist) [] (finalise specty_in) t = mkPE_TyDecl ist args' (explicitNames specty) in (t, (n, args')) -- (normalise (tt_ctxt ist) [] (specType args ty)) _ -> error "Can't happen (getSpecTy)" -- get the clause of a specialised application getSpecClause ist (n, args) = let newnm = sUN ("PE_" ++ show (nsroot n) ++ "_" ++ qhash 5381 (showSep "_" (map showArg args))) in -- UN (show n ++ show (map snd args)) in (n, newnm, mkPE_TermDecl ist newnm n args) where showArg (ExplicitS, n) = qshow n showArg (ImplicitS, n) = qshow n showArg _ = "" qshow (Bind _ _ _) = "fn" qshow (App _ f a) = qshow f ++ qshow a qshow (P _ n _) = show n qshow (Constant c) = show c qshow _ = "" -- Simple but effective string hashing... -- Keep it to 32 bits for readability/debuggability qhash :: Int -> String -> String qhash hash [] = showHex (abs hash `mod` 0xffffffff) "" qhash hash (x:xs) = qhash (hash * 33 + fromEnum x) xs -- | Checks if the clause is a possible left hand side. checkPossible :: ElabInfo -> FC -> Bool -> Name -> PTerm -> Idris Bool checkPossible info fc tcgen fname lhs_in = do ctxt <- getContext i <- getIState let lhs = addImplPat i lhs_in -- if the LHS type checks, it is possible case elaborate ctxt (idris_datatypes i) (idris_name i) (sMN 0 "patLHS") infP initEState (erun fc (buildTC i info ELHS [] fname (allNamesIn lhs_in) (infTerm lhs))) of OK (ElabResult lhs' _ _ ctxt' newDecls highlights newGName, _) -> do setContext ctxt' processTacticDecls info newDecls sendHighlighting highlights updateIState $ \i -> i { idris_name = newGName } let lhs_tm = orderPats (getInferTerm lhs') case recheck ctxt' [] (forget lhs_tm) lhs_tm of OK _ -> return True err -> return False -- if it's a recoverable error, the case may become possible Error err -> if tcgen then return (recoverableCoverage ctxt err) else return (validCoverageCase ctxt err || recoverableCoverage ctxt err) findUnique :: Context -> Env -> Term -> [Name] findUnique ctxt env (Bind n b sc) = let rawTy = forgetEnv (map fst env) (binderTy b) uniq = case check ctxt env rawTy of OK (_, UType UniqueType) -> True OK (_, UType NullType) -> True OK (_, UType AllTypes) -> True _ -> False in if uniq then n : findUnique ctxt ((n, b) : env) sc else findUnique ctxt ((n, b) : env) sc findUnique _ _ _ = [] -- Return the elaborated LHS/RHS, and the original LHS with implicits added elabClause :: ElabInfo -> FnOpts -> (Int, PClause) -> Idris (Either Term (Term, Term), PTerm) elabClause info opts (_, PClause fc fname lhs_in [] PImpossible []) = do let tcgen = Dictionary `elem` opts i <- get let lhs = addImpl [] i lhs_in b <- checkPossible info fc tcgen fname lhs_in case b of True -> tclift $ tfail (At fc (Msg $ show lhs_in ++ " is a valid case")) False -> do ptm <- mkPatTm lhs_in return (Left ptm, lhs) elabClause info opts (cnum, PClause fc fname lhs_in_as withs rhs_in_as whereblock) = do let tcgen = Dictionary `elem` opts push_estack fname False ctxt <- getContext let (lhs_in, rhs_in) = desugarAs lhs_in_as rhs_in_as -- Build the LHS as an "Infer", and pull out its type and -- pattern bindings i <- getIState inf <- isTyInferred fname -- Check if we have "with" patterns outside of "with" block when (isOutsideWith lhs_in && (not $ null withs)) $ ierror $ (At fc (Elaborating "left hand side of " fname Nothing (Msg "unexpected patterns outside of \"with\" block"))) -- get the parameters first, to pass through to any where block let fn_ty = case lookupTy fname ctxt of [t] -> t _ -> error "Can't happen (elabClause function type)" let fn_is = case lookupCtxt fname (idris_implicits i) of [t] -> t _ -> [] let norm_ty = normalise ctxt [] fn_ty let params = getParamsInType i [] fn_is norm_ty let tcparams = getTCParamsInType i [] fn_is norm_ty let lhs = mkLHSapp $ stripLinear i $ stripUnmatchable i $ propagateParams i params norm_ty (allNamesIn lhs_in) (addImplPat i lhs_in) -- let lhs = mkLHSapp $ -- propagateParams i params fn_ty (addImplPat i lhs_in) logElab 10 (show (params, fn_ty) ++ " " ++ showTmImpls (addImplPat i lhs_in)) logElab 5 ("LHS: " ++ show opts ++ "\n" ++ show fc ++ " " ++ showTmImpls lhs) logElab 4 ("Fixed parameters: " ++ show params ++ " from " ++ showTmImpls lhs_in ++ "\n" ++ show (fn_ty, fn_is)) ((ElabResult lhs' dlhs [] ctxt' newDecls highlights newGName, probs, inj), _) <- tclift $ elaborate ctxt (idris_datatypes i) (idris_name i) (sMN 0 "patLHS") infP initEState (do res <- errAt "left hand side of " fname Nothing (erun fc (buildTC i info ELHS opts fname (allNamesIn lhs_in) (infTerm lhs))) probs <- get_probs inj <- get_inj return (res, probs, inj)) setContext ctxt' processTacticDecls info newDecls sendHighlighting highlights updateIState $ \i -> i { idris_name = newGName } when inf $ addTyInfConstraints fc (map (\(x,y,_,_,_,_,_) -> (x,y)) probs) let lhs_tm = orderPats (getInferTerm lhs') let lhs_ty = getInferType lhs' let static_names = getStaticNames i lhs_tm logElab 3 ("Elaborated: " ++ show lhs_tm) logElab 3 ("Elaborated type: " ++ show lhs_ty) logElab 5 ("Injective: " ++ show fname ++ " " ++ show inj) -- If we're inferring metavariables in the type, don't recheck, -- because we're only doing this to try to work out those metavariables ctxt <- getContext (clhs_c, clhsty) <- if not inf then recheckC_borrowing False (PEGenerated `notElem` opts) [] fc id [] lhs_tm else return (lhs_tm, lhs_ty) let clhs = Idris.Core.Evaluate.simplify ctxt [] clhs_c let borrowed = borrowedNames [] clhs -- These are the names we're not allowed to use on the RHS, because -- they're UniqueTypes and borrowed from another function. -- FIXME: There is surely a nicer way than this... -- Issue #1615 on the Issue Tracker. -- https://github.com/idris-lang/Idris-dev/issues/1615 when (not (null borrowed)) $ logElab 5 ("Borrowed names on LHS: " ++ show borrowed) logElab 3 ("Normalised LHS: " ++ showTmImpls (delabMV i clhs)) rep <- useREPL when rep $ do addInternalApp (fc_fname fc) (fst . fc_start $ fc) (delabMV i clhs) -- TODO: Should use span instead of line and filename? addIBC (IBCLineApp (fc_fname fc) (fst . fc_start $ fc) (delabMV i clhs)) logElab 5 ("Checked " ++ show clhs ++ "\n" ++ show clhsty) -- Elaborate where block ist <- getIState ctxt <- getContext windex <- getName let decls = nub (concatMap declared whereblock) let defs = nub (decls ++ concatMap defined whereblock) let newargs_all = pvars ist lhs_tm -- Unique arguments must be passed to the where block explicitly -- (since we can't control "usage" easlily otherwise). Remove them -- from newargs here let uniqargs = findUnique ctxt [] lhs_tm let newargs = filter (\(n,_) -> n `notElem` uniqargs) newargs_all let winfo = (pinfo info newargs defs windex) { elabFC = Just fc } let wb = map (mkStatic static_names) $ map (expandInstanceScope ist decorate newargs defs) $ map (expandParamsD False ist decorate newargs defs) whereblock -- Split the where block into declarations with a type, and those -- without -- Elaborate those with a type *before* RHS, those without *after* let (wbefore, wafter) = sepBlocks wb logElab 5 $ "Where block:\n " ++ show wbefore ++ "\n" ++ show wafter mapM_ (rec_elabDecl info EAll winfo) wbefore -- Now build the RHS, using the type of the LHS as the goal. i <- getIState -- new implicits from where block logElab 5 (showTmImpls (expandParams decorate newargs defs (defs \\ decls) rhs_in)) let rhs = rhs_trans info $ addImplBoundInf i (map fst newargs_all) (defs \\ decls) (expandParams decorate newargs defs (defs \\ decls) rhs_in) logElab 2 $ "RHS: " ++ show (map fst newargs_all) ++ " " ++ showTmImpls rhs ctxt <- getContext -- new context with where block added logElab 5 "STARTING CHECK" ((rhs', defer, holes, is, probs, ctxt', newDecls, highlights, newGName), _) <- tclift $ elaborate ctxt (idris_datatypes i) (idris_name i) (sMN 0 "patRHS") clhsty initEState (do pbinds ist lhs_tm -- proof search can use explicitly written names mapM_ addPSname (allNamesIn lhs_in) mapM_ setinj (nub (tcparams ++ inj)) setNextName (ElabResult _ _ is ctxt' newDecls highlights newGName) <- errAt "right hand side of " fname (Just clhsty) (erun fc (build i winfo ERHS opts fname rhs)) errAt "right hand side of " fname (Just clhsty) (erun fc $ psolve lhs_tm) tt <- get_term aux <- getAux let (tm, ds) = runState (collectDeferred (Just fname) (map fst $ case_decls aux) ctxt tt) [] probs <- get_probs hs <- get_holes return (tm, ds, hs, is, probs, ctxt', newDecls, highlights, newGName)) setContext ctxt' processTacticDecls info newDecls sendHighlighting highlights updateIState $ \i -> i { idris_name = newGName } when inf $ addTyInfConstraints fc (map (\(x,y,_,_,_,_,_) -> (x,y)) probs) logElab 5 "DONE CHECK" logElab 4 $ "---> " ++ show rhs' when (not (null defer)) $ logElab 1 $ "DEFERRED " ++ show (map (\ (n, (_,_,t,_)) -> (n, t)) defer) -- If there's holes, set the metavariables as undefinable def' <- checkDef fc (\n -> Elaborating "deferred type of " n Nothing) (null holes) defer let def'' = map (\(n, (i, top, t, ns)) -> (n, (i, top, t, ns, False, null holes))) def' addDeferred def'' mapM_ (\(n, _) -> addIBC (IBCDef n)) def'' when (not (null def')) $ do mapM_ defer_totcheck (map (\x -> (fc, fst x)) def'') -- Now the remaining deferred (i.e. no type declarations) clauses -- from the where block mapM_ (rec_elabDecl info EAll winfo) wafter mapM_ (elabCaseBlock winfo opts) is ctxt <- getContext logElab 5 $ "Rechecking" logElab 6 $ " ==> " ++ show (forget rhs') (crhs, crhsty) -- if there's holes && deferred things, it's okay -- but we'll need to freeze the definition and not -- allow the deferred things to be definable -- (this is just to allow users to inspect intermediate -- things) <- if (null holes || null def') && not inf then recheckC_borrowing True (PEGenerated `notElem` opts) borrowed fc id [] rhs' else return (rhs', clhsty) logElab 6 $ " ==> " ++ showEnvDbg [] crhsty ++ " against " ++ showEnvDbg [] clhsty -- If there's holes, make sure this definition is frozen when (not (null holes)) $ do logElab 5 $ "Making " ++ show fname ++ " frozen due to " ++ show holes setAccessibility fname Frozen ctxt <- getContext let constv = next_tvar ctxt case LState.runStateT (convertsC ctxt [] crhsty clhsty) (constv, []) of OK (_, cs) -> when (PEGenerated `notElem` opts) $ do addConstraints fc cs logElab 6 $ "CONSTRAINTS ADDED: " ++ show cs ++ "\n" ++ show (clhsty, crhsty) return () Error e -> ierror (At fc (CantUnify False (clhsty, Nothing) (crhsty, Nothing) e [] 0)) i <- getIState checkInferred fc (delab' i crhs True True) rhs -- if the function is declared '%error_reverse', or its type, -- then we'll try running it in reverse to improve error messages let (ret_fam, _) = unApply (getRetTy crhsty) rev <- case ret_fam of P _ rfamn _ -> case lookupCtxt rfamn (idris_datatypes i) of [TI _ _ dopts _ _] -> return (DataErrRev `elem` dopts) _ -> return False _ -> return False when (rev || ErrorReverse `elem` opts) $ do addIBC (IBCErrRev (crhs, clhs)) addErrRev (crhs, clhs) pop_estack return $ (Right (clhs, crhs), lhs) where pinfo :: ElabInfo -> [(Name, PTerm)] -> [Name] -> Int -> ElabInfo pinfo info ns ds i = let newps = params info ++ ns dsParams = map (\n -> (n, map fst newps)) ds newb = addAlist dsParams (inblock info) l = liftname info in info { params = newps, inblock = newb, liftname = id -- (\n -> case lookupCtxt n newb of -- Nothing -> n -- _ -> MN i (show n)) . l } -- Find the variable names which appear under a 'Ownership.Read' so that -- we know they can't be used on the RHS borrowedNames :: [Name] -> Term -> [Name] borrowedNames env (App _ (App _ (P _ (NS (UN lend) [owner]) _) _) arg) | owner == txt "Ownership" && (lend == txt "lend" || lend == txt "Read") = getVs arg where getVs (V i) = [env!!i] getVs (App _ f a) = nub $ getVs f ++ getVs a getVs _ = [] borrowedNames env (App _ f a) = nub $ borrowedNames env f ++ borrowedNames env a borrowedNames env (Bind n b sc) = nub $ borrowedB b ++ borrowedNames (n:env) sc where borrowedB (Let t v) = nub $ borrowedNames env t ++ borrowedNames env v borrowedB b = borrowedNames env (binderTy b) borrowedNames _ _ = [] mkLHSapp t@(PRef _ _ _) = PApp fc t [] mkLHSapp t = t decorate (NS x ns) = NS (SN (WhereN cnum fname x)) ns -- ++ [show cnum]) -- = NS (UN ('#':show x)) (ns ++ [show cnum, show fname]) decorate x = SN (WhereN cnum fname x) -- = NS (SN (WhereN cnum fname x)) [show cnum] -- = NS (UN ('#':show x)) [show cnum, show fname] sepBlocks bs = sepBlocks' [] bs where sepBlocks' ns (d@(PTy _ _ _ _ _ n _ t) : bs) = let (bf, af) = sepBlocks' (n : ns) bs in (d : bf, af) sepBlocks' ns (d@(PClauses _ _ n _) : bs) | not (n `elem` ns) = let (bf, af) = sepBlocks' ns bs in (bf, d : af) sepBlocks' ns (b : bs) = let (bf, af) = sepBlocks' ns bs in (b : bf, af) sepBlocks' ns [] = ([], []) -- term is not within "with" block isOutsideWith :: PTerm -> Bool isOutsideWith (PApp _ (PRef _ _ (SN (WithN _ _))) _) = False isOutsideWith _ = True elabClause info opts (_, PWith fc fname lhs_in withs wval_in pn_in withblock) = do let tcgen = Dictionary `elem` opts ctxt <- getContext -- Build the LHS as an "Infer", and pull out its type and -- pattern bindings i <- getIState -- get the parameters first, to pass through to any where block let fn_ty = case lookupTy fname ctxt of [t] -> t _ -> error "Can't happen (elabClause function type)" let fn_is = case lookupCtxt fname (idris_implicits i) of [t] -> t _ -> [] let params = getParamsInType i [] fn_is (normalise ctxt [] fn_ty) let lhs = stripLinear i $ stripUnmatchable i $ propagateParams i params fn_ty (allNamesIn lhs_in) (addImplPat i lhs_in) logElab 2 ("LHS: " ++ show lhs) (ElabResult lhs' dlhs [] ctxt' newDecls highlights newGName, _) <- tclift $ elaborate ctxt (idris_datatypes i) (idris_name i) (sMN 0 "patLHS") infP initEState (errAt "left hand side of with in " fname Nothing (erun fc (buildTC i info ELHS opts fname (allNamesIn lhs_in) (infTerm lhs))) ) setContext ctxt' processTacticDecls info newDecls sendHighlighting highlights updateIState $ \i -> i { idris_name = newGName } ctxt <- getContext let lhs_tm = orderPats (getInferTerm lhs') let lhs_ty = getInferType lhs' let ret_ty = getRetTy (explicitNames (normalise ctxt [] lhs_ty)) let static_names = getStaticNames i lhs_tm logElab 5 (show lhs_tm ++ "\n" ++ show static_names) (clhs, clhsty) <- recheckC fc id [] lhs_tm logElab 5 ("Checked " ++ show clhs) let bargs = getPBtys (explicitNames (normalise ctxt [] lhs_tm)) let wval = rhs_trans info $ addImplBound i (map fst bargs) wval_in logElab 5 ("Checking " ++ showTmImpls wval) -- Elaborate wval in this context ((wval', defer, is, ctxt', newDecls, highlights, newGName), _) <- tclift $ elaborate ctxt (idris_datatypes i) (idris_name i) (sMN 0 "withRHS") (bindTyArgs PVTy bargs infP) initEState (do pbinds i lhs_tm -- proof search can use explicitly written names mapM_ addPSname (allNamesIn lhs_in) setNextName -- TODO: may want where here - see winfo abpve (ElabResult _ d is ctxt' newDecls highlights newGName) <- errAt "with value in " fname Nothing (erun fc (build i info ERHS opts fname (infTerm wval))) erun fc $ psolve lhs_tm tt <- get_term return (tt, d, is, ctxt', newDecls, highlights, newGName)) setContext ctxt' processTacticDecls info newDecls sendHighlighting highlights updateIState $ \i -> i { idris_name = newGName } def' <- checkDef fc iderr True defer let def'' = map (\(n, (i, top, t, ns)) -> (n, (i, top, t, ns, False, True))) def' addDeferred def'' mapM_ (elabCaseBlock info opts) is logElab 5 ("Checked wval " ++ show wval') ctxt <- getContext (cwval, cwvalty) <- recheckC fc id [] (getInferTerm wval') let cwvaltyN = explicitNames (normalise ctxt [] cwvalty) let cwvalN = explicitNames (normalise ctxt [] cwval) logElab 3 ("With type " ++ show cwvalty ++ "\nRet type " ++ show ret_ty) -- We're going to assume the with type is not a function shortly, -- so report an error if it is (you can't match on a function anyway -- so this doesn't lose anything) case getArgTys cwvaltyN of [] -> return () (_:_) -> ierror $ At fc (WithFnType cwvalty) let pvars = map fst (getPBtys cwvalty) -- we need the unelaborated term to get the names it depends on -- rather than a de Bruijn index. let pdeps = usedNamesIn pvars i (delab i cwvalty) let (bargs_pre, bargs_post) = split pdeps bargs [] let mpn = case pn_in of Nothing -> Nothing Just (n, nfc) -> Just (uniqueName n (map fst bargs)) -- Highlight explicit proofs sendHighlighting $ [(fc, AnnBoundName n False) | (n, fc) <- maybeToList pn_in] logElab 10 ("With type " ++ show (getRetTy cwvaltyN) ++ " depends on " ++ show pdeps ++ " from " ++ show pvars) logElab 10 ("Pre " ++ show bargs_pre ++ "\nPost " ++ show bargs_post) windex <- getName -- build a type declaration for the new function: -- (ps : Xs) -> (withval : cwvalty) -> (ps' : Xs') -> ret_ty let wargval = getRetTy cwvalN let wargtype = getRetTy cwvaltyN let wargname = sMN windex "warg" logElab 5 ("Abstract over " ++ show wargval ++ " in " ++ show wargtype) let wtype = bindTyArgs (flip (Pi Nothing) (TType (UVar 0))) (bargs_pre ++ (wargname, wargtype) : map (abstract wargname wargval wargtype) bargs_post ++ case mpn of Just pn -> [(pn, mkApp (P Ref eqTy Erased) [wargtype, wargtype, P Bound wargname Erased, wargval])] Nothing -> []) (substTerm wargval (P Bound wargname wargtype) ret_ty) logElab 3 ("New function type " ++ show wtype) let wname = SN (WithN windex fname) let imps = getImps wtype -- add to implicits context putIState (i { idris_implicits = addDef wname imps (idris_implicits i) }) let statics = getStatics static_names wtype logElab 5 ("Static positions " ++ show statics) i <- getIState putIState (i { idris_statics = addDef wname statics (idris_statics i) }) addIBC (IBCDef wname) addIBC (IBCImp wname) addIBC (IBCStatic wname) def' <- checkDef fc iderr True [(wname, (-1, Nothing, wtype, []))] let def'' = map (\(n, (i, top, t, ns)) -> (n, (i, top, t, ns, False, True))) def' addDeferred def'' -- in the subdecls, lhs becomes: -- fname pats | wpat [rest] -- ==> fname' ps wpat [rest], match pats against toplevel for ps wb <- mapM (mkAuxC mpn wname lhs (map fst bargs_pre) (map fst bargs_post)) withblock logElab 3 ("with block " ++ show wb) -- propagate totality assertion to the new definitions setFlags wname [Inlinable] when (AssertTotal `elem` opts) $ setFlags wname [Inlinable, AssertTotal] i <- getIState let rhstrans' = updateWithTerm i mpn wname lhs (map fst bargs_pre) (map fst (bargs_post)) . rhs_trans info mapM_ (rec_elabDecl info EAll (info { rhs_trans = rhstrans' })) wb -- rhs becomes: fname' ps_pre wval ps_post Refl let rhs = PApp fc (PRef fc [] wname) (map (pexp . (PRef fc []) . fst) bargs_pre ++ pexp wval : (map (pexp . (PRef fc []) . fst) bargs_post) ++ case mpn of Nothing -> [] Just _ -> [pexp (PApp NoFC (PRef NoFC [] eqCon) [ pimp (sUN "A") Placeholder False , pimp (sUN "x") Placeholder False ])]) logElab 5 ("New RHS " ++ showTmImpls rhs) ctxt <- getContext -- New context with block added i <- getIState ((rhs', defer, is, ctxt', newDecls, highlights, newGName), _) <- tclift $ elaborate ctxt (idris_datatypes i) (idris_name i) (sMN 0 "wpatRHS") clhsty initEState (do pbinds i lhs_tm setNextName (ElabResult _ d is ctxt' newDecls highlights newGName) <- erun fc (build i info ERHS opts fname rhs) psolve lhs_tm tt <- get_term return (tt, d, is, ctxt', newDecls, highlights, newGName)) setContext ctxt' processTacticDecls info newDecls sendHighlighting highlights updateIState $ \i -> i { idris_name = newGName } def' <- checkDef fc iderr True defer let def'' = map (\(n, (i, top, t, ns)) -> (n, (i, top, t, ns, False, True))) def' addDeferred def'' mapM_ (elabCaseBlock info opts) is logElab 5 ("Checked RHS " ++ show rhs') (crhs, crhsty) <- recheckC fc id [] rhs' return $ (Right (clhs, crhs), lhs) where getImps (Bind n (Pi _ _ _) t) = pexp Placeholder : getImps t getImps _ = [] mkAuxC pn wname lhs ns ns' (PClauses fc o n cs) = do cs' <- mapM (mkAux pn wname lhs ns ns') cs return $ PClauses fc o wname cs' mkAuxC pn wname lhs ns ns' d = return $ d mkAux pn wname toplhs ns ns' (PClause fc n tm_in (w:ws) rhs wheres) = do i <- getIState let tm = addImplPat i tm_in logElab 2 ("Matching " ++ showTmImpls tm ++ " against " ++ showTmImpls toplhs) case matchClause i toplhs tm of Left (a,b) -> ifail $ show fc ++ ":with clause does not match top level" Right mvars -> do logElab 3 ("Match vars : " ++ show mvars) lhs <- updateLHS n pn wname mvars ns ns' (fullApp tm) w return $ PClause fc wname lhs ws rhs wheres mkAux pn wname toplhs ns ns' (PWith fc n tm_in (w:ws) wval pn' withs) = do i <- getIState let tm = addImplPat i tm_in logElab 2 ("Matching " ++ showTmImpls tm ++ " against " ++ showTmImpls toplhs) withs' <- mapM (mkAuxC pn wname toplhs ns ns') withs case matchClause i toplhs tm of Left (a,b) -> trace ("matchClause: " ++ show a ++ " =/= " ++ show b) (ifail $ show fc ++ "with clause does not match top level") Right mvars -> do lhs <- updateLHS n pn wname mvars ns ns' (fullApp tm) w return $ PWith fc wname lhs ws wval pn' withs' mkAux pn wname toplhs ns ns' c = ifail $ show fc ++ ":badly formed with clause" addArg (PApp fc f args) w = PApp fc f (args ++ [pexp w]) addArg (PRef fc hls f) w = PApp fc (PRef fc hls f) [pexp w] -- ns, arguments which don't depend on the with argument -- ns', arguments which do updateLHS n pn wname mvars ns_in ns_in' (PApp fc (PRef fc' hls' n') args) w = let ns = map (keepMvar (map fst mvars) fc') ns_in ns' = map (keepMvar (map fst mvars) fc') ns_in' in return $ substMatches mvars $ PApp fc (PRef fc' [] wname) (map pexp ns ++ pexp w : (map pexp ns') ++ case pn of Nothing -> [] Just pnm -> [pexp (PRef fc [] pnm)]) updateLHS n pn wname mvars ns_in ns_in' tm w = updateLHS n pn wname mvars ns_in ns_in' (PApp fc tm []) w -- Only keep a var as a pattern variable in the with block if it's -- matched in the top level pattern keepMvar mvs fc v | v `elem` mvs = PRef fc [] v | otherwise = Placeholder updateWithTerm :: IState -> Maybe Name -> Name -> PTerm -> [Name] -> [Name] -> PTerm -> PTerm updateWithTerm ist pn wname toplhs ns_in ns_in' tm = mapPT updateApp tm where arity (PApp _ _ as) = length as arity _ = 0 lhs_arity = arity toplhs currentFn fname (PAlternative _ _ as) | Just tm <- getApp as = tm where getApp (tm@(PApp _ (PRef _ _ f) _) : as) | f == fname = Just tm getApp (_ : as) = getApp as getApp [] = Nothing currentFn _ tm = tm updateApp wtm@(PWithApp fcw tm_in warg) = let tm = currentFn fname tm_in in case matchClause ist toplhs tm of Left _ -> PElabError (Msg (show fc ++ ":with application does not match top level ")) Right mvars -> let ns = map (keepMvar (map fst mvars) fcw) ns_in ns' = map (keepMvar (map fst mvars) fcw) ns_in' wty = lookupTyExact wname (tt_ctxt ist) res = substMatches mvars $ PApp fcw (PRef fcw [] wname) (map pexp ns ++ pexp warg : (map pexp ns') ++ case pn of Nothing -> [] Just pnm -> [pexp (PRef fc [] pnm)]) in case wty of Nothing -> res -- can't happen! Just ty -> addResolves ty res updateApp tm = tm addResolves ty (PApp fc f args) = PApp fc f (addResolvesArgs fc ty args) addResolves ty tm = tm -- if an argument's type is a type class, and is otherwise to -- be inferred, then resolve it with instance search -- This is something of a hack, because matching on the top level -- application won't find this information for us addResolvesArgs :: FC -> Term -> [PArg] -> [PArg] addResolvesArgs fc (Bind n (Pi _ ty _) sc) (a : args) | (P _ cn _, _) <- unApply ty, getTm a == Placeholder = case lookupCtxtExact cn (idris_classes ist) of Just _ -> a { getTm = PResolveTC fc } : addResolvesArgs fc sc args Nothing -> a : addResolvesArgs fc sc args addResolvesArgs fc (Bind n (Pi _ ty _) sc) (a : args) = a : addResolvesArgs fc sc args addResolvesArgs fc _ args = args fullApp (PApp _ (PApp fc f args) xs) = fullApp (PApp fc f (args ++ xs)) fullApp x = x split [] rest pre = (reverse pre, rest) split deps ((n, ty) : rest) pre | n `elem` deps = split (deps \\ [n]) rest ((n, ty) : pre) | otherwise = split deps rest ((n, ty) : pre) split deps [] pre = (reverse pre, []) abstract wn wv wty (n, argty) = (n, substTerm wv (P Bound wn wty) argty) -- Apply a transformation to all RHSes and nested RHSs mapRHS :: (PTerm -> PTerm) -> PClause -> PClause mapRHS f (PClause fc n lhs args rhs ws) = PClause fc n lhs args (f rhs) (map (mapRHSdecl f) ws) mapRHS f (PWith fc n lhs args warg prf ws) = PWith fc n lhs args (f warg) prf (map (mapRHSdecl f) ws) mapRHS f (PClauseR fc args rhs ws) = PClauseR fc args (f rhs) (map (mapRHSdecl f) ws) mapRHS f (PWithR fc args warg prf ws) = PWithR fc args (f warg) prf (map (mapRHSdecl f) ws) mapRHSdecl :: (PTerm -> PTerm) -> PDecl -> PDecl mapRHSdecl f (PClauses fc opt n cs) = PClauses fc opt n (map (mapRHS f) cs) mapRHSdecl f t = t