Idris2-boot/src/TTImp/ProcessDef.idr
Edwin Brady 2a2a20849d Add default implicit arguments
These are part of the core QTT now, so any substitutions or dependencies
will be dealt with as they should.
2020-02-25 14:09:08 +00:00

710 lines
30 KiB
Idris

module TTImp.ProcessDef
import Core.CaseBuilder
import Core.CaseTree
import Core.Context
import Core.Core
import Core.Coverage
import Core.Env
import Core.Hash
import Core.LinearCheck
import Core.Metadata
import Core.Normalise
import Core.Termination
import Core.Value
import Core.UnifyState
import TTImp.BindImplicits
import TTImp.Elab
import TTImp.Elab.Check
import TTImp.Impossible
import TTImp.TTImp
import TTImp.Unelab
import TTImp.Utils
import TTImp.WithClause
import Data.NameMap
mutual
mismatchNF : Defs -> NF vars -> NF vars -> Core Bool
mismatchNF defs (NTCon _ xn xt _ xargs) (NTCon _ yn yt _ yargs)
= if xn /= yn
then pure True
else anyM (mismatch defs) (zip xargs yargs)
mismatchNF defs (NDCon _ _ xt _ xargs) (NDCon _ _ yt _ yargs)
= if xt /= yt
then pure True
else anyM (mismatch defs) (zip xargs yargs)
mismatchNF defs (NPrimVal _ xc) (NPrimVal _ yc) = pure (xc /= yc)
mismatchNF defs (NDelayed _ _ x) (NDelayed _ _ y) = mismatchNF defs x y
mismatchNF defs (NDelay _ _ _ x) (NDelay _ _ _ y)
= mismatchNF defs !(evalClosure defs x) !(evalClosure defs y)
mismatchNF _ _ _ = pure False
mismatch : Defs -> (Closure vars, Closure vars) -> Core Bool
mismatch defs (x, y)
= mismatchNF defs !(evalClosure defs x) !(evalClosure defs y)
-- If the terms have the same type constructor at the head, and one of
-- the argument positions has different constructors at its head, then this
-- is an impossible case, so return True
export
impossibleOK : Defs -> NF vars -> NF vars -> Core Bool
impossibleOK defs (NTCon _ xn xt xa xargs) (NTCon _ yn yt ya yargs)
= if xn == yn
then anyM (mismatch defs) (zip xargs yargs)
else pure False
-- If it's a data constructor, any mismatch will do
impossibleOK defs (NDCon _ _ xt _ xargs) (NDCon _ _ yt _ yargs)
= if xt /= yt
then pure True
else anyM (mismatch defs) (zip xargs yargs)
impossibleOK defs (NPrimVal _ x) (NPrimVal _ y) = pure (x /= y)
impossibleOK defs (NDCon _ _ _ _ _) (NPrimVal _ _) = pure True
impossibleOK defs (NPrimVal _ _) (NDCon _ _ _ _ _) = pure True
impossibleOK defs x y = pure False
export
impossibleErrOK : {auto c : Ref Ctxt Defs} ->
Defs -> Error -> Core Bool
impossibleErrOK defs (CantConvert fc env l r)
= do logTerm 10 "Impossible" !(normalise defs env l)
logTerm 10 " ...and" !(normalise defs env r)
impossibleOK defs !(nf defs env l)
!(nf defs env r)
impossibleErrOK defs (CantSolveEq fc env l r)
= do logTerm 10 "Impossible" !(normalise defs env l)
logTerm 10 " ...and" !(normalise defs env r)
impossibleOK defs !(nf defs env l)
!(nf defs env r)
impossibleErrOK defs (BadDotPattern _ _ ErasedArg _ _) = pure True
impossibleErrOK defs (CyclicMeta _ _) = pure True
impossibleErrOK defs (AllFailed errs)
= anyM (impossibleErrOK defs) (map snd errs)
impossibleErrOK defs (WhenUnifying _ _ _ _ err)
= impossibleErrOK defs err
impossibleErrOK defs _ = pure False
-- Given a type checked LHS and its type, return the environment in which we
-- should check the RHS, the LHS and its type in that environment,
-- and a function which turns a checked RHS into a
-- pattern clause
-- The 'SubVars' proof contains a proof that refers to the *inner* environment,
-- so all the outer things are marked as 'DropCons'
extendEnv : Env Term vars -> SubVars inner vars ->
NestedNames vars ->
Term vars -> Term vars ->
Core (vars' **
(SubVars inner vars',
Env Term vars', NestedNames vars',
Term vars', Term vars'))
extendEnv env p nest (Bind _ n (PVar c pi tmty) sc) (Bind _ n' (PVTy _ _) tysc) with (nameEq n n')
extendEnv env p nest (Bind _ n (PVar c pi tmty) sc) (Bind _ n' (PVTy _ _) tysc) | Nothing
= throw (InternalError "Can't happen: names don't match in pattern type")
extendEnv env p nest (Bind _ n (PVar c pi tmty) sc) (Bind _ n (PVTy _ _) tysc) | (Just Refl)
= extendEnv (PVar c pi tmty :: env) (DropCons p) (weaken nest) sc tysc
extendEnv env p nest (Bind _ n (PLet c tmval tmty) sc) (Bind _ n' (PLet _ _ _) tysc) with (nameEq n n')
extendEnv env p nest (Bind _ n (PLet c tmval tmty) sc) (Bind _ n' (PLet _ _ _) tysc) | Nothing
= throw (InternalError "Can't happen: names don't match in pattern type")
-- PLet on the left becomes Let on the right, to give it computational force
extendEnv env p nest (Bind _ n (PLet c tmval tmty) sc) (Bind _ n (PLet _ _ _) tysc) | (Just Refl)
= extendEnv (Let c tmval tmty :: env) (DropCons p) (weaken nest) sc tysc
extendEnv env p nest tm ty
= pure (_ ** (p, env, nest, tm, ty))
-- Find names which are applied to a function in a Rig1/Rig0 position,
-- so that we know how they should be bound on the right hand side of the
-- pattern.
-- 'bound' counts the number of variables locally bound; these are the
-- only ones we're checking linearity of (we may be shadowing names if this
-- is a local definition, so we need to leave the earlier ones alone)
findLinear : {auto c : Ref Ctxt Defs} ->
Bool -> Nat -> RigCount -> Term vars ->
Core (List (Name, RigCount))
findLinear top bound rig (Bind fc n b sc)
= findLinear top (S bound) rig sc
findLinear top bound rig (As fc _ _ p)
= findLinear top bound rig p
findLinear top bound rig tm
= case getFnArgs tm of
(Ref _ _ n, []) => pure []
(Ref _ nt n, args)
=> do defs <- get Ctxt
Just nty <- lookupTyExact n (gamma defs)
| Nothing => pure []
findLinArg (accessible nt rig) !(nf defs [] nty) args
_ => pure []
where
accessible : NameType -> RigCount -> RigCount
accessible Func r = if top then r else Rig0
accessible _ r = r
findLinArg : RigCount -> NF [] -> List (Term vars) ->
Core (List (Name, RigCount))
findLinArg rig ty (As fc UseLeft _ p :: as)
= findLinArg rig ty (p :: as)
findLinArg rig ty (As fc UseRight p _ :: as)
= findLinArg rig ty (p :: as)
findLinArg rig (NBind _ x (Pi c _ _) sc) (Local {name=a} fc _ idx prf :: as)
= do defs <- get Ctxt
if idx < bound
then do sc' <- sc defs (toClosure defaultOpts [] (Ref fc Bound x))
pure $ (a, rigMult c rig) ::
!(findLinArg rig sc' as)
else do sc' <- sc defs (toClosure defaultOpts [] (Ref fc Bound x))
findLinArg rig sc' as
findLinArg rig (NBind fc x (Pi c _ _) sc) (a :: as)
= do defs <- get Ctxt
pure $ !(findLinear False bound (rigMult c rig) a) ++
!(findLinArg rig !(sc defs (toClosure defaultOpts [] (Ref fc Bound x))) as)
findLinArg rig ty (a :: as)
= pure $ !(findLinear False bound rig a) ++ !(findLinArg rig ty as)
findLinArg _ _ [] = pure []
setLinear : List (Name, RigCount) -> Term vars -> Term vars
setLinear vs (Bind fc x (PVar c p ty) sc)
= case lookup x vs of
Just c' => Bind fc x (PVar c' p ty) (setLinear vs sc)
_ => Bind fc x (PVar c p ty) (setLinear vs sc)
setLinear vs (Bind fc x (PVTy c ty) sc)
= case lookup x vs of
Just c' => Bind fc x (PVTy c' ty) (setLinear vs sc)
_ => Bind fc x (PVTy c ty) (setLinear vs sc)
setLinear vs tm = tm
-- Combining multiplicities on LHS:
-- Rig1 + Rig1/W not valid, since it means we have repeated use of name
-- Rig0 + RigW = RigW
-- Rig0 + Rig1 = Rig1
combineLinear : FC -> List (Name, RigCount) ->
Core (List (Name, RigCount))
combineLinear loc [] = pure []
combineLinear loc ((n, count) :: cs)
= case lookupAll n cs of
[] => pure $ (n, count) :: !(combineLinear loc cs)
counts => do count' <- combineAll count counts
pure $ (n, count') ::
!(combineLinear loc (filter notN cs))
where
notN : (Name, RigCount) -> Bool
notN (n', _) = n /= n'
lookupAll : Name -> List (Name, RigCount) -> List RigCount
lookupAll n [] = []
lookupAll n ((n', c) :: cs)
= if n == n' then c :: lookupAll n cs else lookupAll n cs
combine : RigCount -> RigCount -> Core RigCount
combine Rig1 Rig1 = throw (LinearUsed loc 2 n)
combine Rig1 RigW = throw (LinearUsed loc 2 n)
combine RigW Rig1 = throw (LinearUsed loc 2 n)
combine RigW RigW = pure RigW
combine Rig0 c = pure c
combine c Rig0 = pure c
combineAll : RigCount -> List RigCount -> Core RigCount
combineAll c [] = pure c
combineAll c (c' :: cs)
= do newc <- combine c c'
combineAll newc cs
checkLHS : {vars : _} ->
{auto c : Ref Ctxt Defs} ->
{auto m : Ref MD Metadata} ->
{auto u : Ref UST UState} ->
(mult : RigCount) -> (hashit : Bool) ->
Int -> List ElabOpt -> NestedNames vars -> Env Term vars ->
FC -> RawImp ->
Core (RawImp, -- checked LHS with implicits added
(vars' ** (SubVars vars vars',
Env Term vars', NestedNames vars',
Term vars', Term vars')))
checkLHS {vars} mult hashit n opts nest env fc lhs_in
= do defs <- get Ctxt
lhs_raw <- lhsInCurrentNS nest lhs_in
autoimp <- isUnboundImplicits
setUnboundImplicits True
(_, lhs_bound) <- bindNames False lhs_raw
setUnboundImplicits autoimp
lhs <- implicitsAs defs vars lhs_bound
log 5 $ "Checking LHS of " ++ show !(getFullName (Resolved n)) ++
" " ++ show lhs
logEnv 5 "In env" env
(lhstm, lhstyg) <-
wrapError (InLHS fc !(getFullName (Resolved n))) $
elabTerm n (InLHS mult) opts nest env
(IBindHere fc PATTERN lhs) Nothing
logTerm 5 "Checked LHS term" lhstm
lhsty <- getTerm lhstyg
-- Normalise the LHS to get any functions or let bindings evaluated
-- (this might be allowed, e.g. for 'fromInteger')
defs <- get Ctxt
lhstm <- normaliseLHS defs (letToLam env) lhstm
lhsty <- normaliseHoles defs env lhsty
linvars_in <- findLinear True 0 Rig1 lhstm
logTerm 10 "Checked LHS term after normalise" lhstm
log 5 $ "Linearity of names in " ++ show n ++ ": " ++
show linvars_in
linvars <- combineLinear fc linvars_in
let lhstm_lin = setLinear linvars lhstm
let lhsty_lin = setLinear linvars lhsty
logTerm 3 "LHS term" lhstm_lin
logTerm 5 "LHS type" lhsty_lin
setHoleLHS (bindEnv fc env lhstm_lin)
ext <- extendEnv env SubRefl nest lhstm_lin lhsty_lin
pure (lhs, ext)
plicit : Binder (Term vars) -> PiInfo RawImp
plicit (Pi _ p _) = forgetDef p
plicit (PVar _ p _) = forgetDef p
plicit _ = Explicit
bindNotReq : {vs : _} ->
FC -> Int -> Env Term vs -> (sub : SubVars pre vs) ->
List (PiInfo RawImp, Name) ->
Term vs -> (List (PiInfo RawImp, Name), Term pre)
bindNotReq fc i [] SubRefl ns tm = (ns, embed tm)
bindNotReq fc i (b :: env) SubRefl ns tm
= let tmptm = subst (Ref fc Bound (MN "arg" i)) tm
(ns', btm) = bindNotReq fc (1 + i) env SubRefl ns tmptm in
(ns', refToLocal (MN "arg" i) _ btm)
bindNotReq fc i (b :: env) (KeepCons p) ns tm
= let tmptm = subst (Ref fc Bound (MN "arg" i)) tm
(ns', btm) = bindNotReq fc (1 + i) env p ns tmptm in
(ns', refToLocal (MN "arg" i) _ btm)
bindNotReq {vs = n :: _} fc i (b :: env) (DropCons p) ns tm
= bindNotReq fc i env p ((plicit b, n) :: ns)
(Bind fc _ (Pi (multiplicity b) Explicit (binderType b)) tm)
bindReq : {vs : _} ->
FC -> Env Term vs -> (sub : SubVars pre vs) ->
List (PiInfo RawImp, Name) ->
Term pre -> Maybe (List (PiInfo RawImp, Name), List Name, ClosedTerm)
bindReq {vs} fc env SubRefl ns tm
= pure (ns, notLets [] _ env, abstractEnvType fc env tm)
where
notLets : List Name -> (vars : List Name) -> Env Term vars -> List Name
notLets acc [] _ = acc
notLets acc (v :: vs) (Let _ _ _ :: env) = notLets acc vs env
notLets acc (v :: vs) (_ :: env) = notLets (v :: acc) vs env
bindReq {vs = n :: _} fc (b :: env) (KeepCons p) ns tm
= do b' <- shrinkBinder b p
bindReq fc env p ((plicit b, n) :: ns)
(Bind fc _ (Pi (multiplicity b) Explicit (binderType b')) tm)
bindReq fc (b :: env) (DropCons p) ns tm
= bindReq fc env p ns tm
-- Return whether any of the pattern variables are in a trivially empty
-- type, where trivally empty means one of:
-- * No constructors
-- * Every constructor of the family has a return type which conflicts with
-- the given constructor's type
hasEmptyPat : Defs -> Env Term vars -> Term vars -> Core Bool
hasEmptyPat defs env (Bind fc x (PVar c p ty) sc)
= pure $ !(isEmpty defs !(nf defs env ty))
|| !(hasEmptyPat defs (PVar c p ty :: env) sc)
hasEmptyPat defs env _ = pure False
-- For checking with blocks as nested names
applyEnv : {auto c : Ref Ctxt Defs} ->
Env Term vars -> Name ->
Core (Name, (Maybe Name, Nat, FC -> NameType -> Term vars))
applyEnv env withname
= do n' <- resolveName withname
pure (withname, (Just withname, lengthNoLet env,
\fc, nt => applyTo fc
(Ref fc nt (Resolved n')) env))
-- Check a pattern clause, returning the component of the 'Case' expression it
-- represents, or Nothing if it's an impossible clause
export
checkClause : {vars : _} ->
{auto c : Ref Ctxt Defs} ->
{auto m : Ref MD Metadata} ->
{auto u : Ref UST UState} ->
(mult : RigCount) -> (hashit : Bool) ->
Int -> List ElabOpt -> NestedNames vars -> Env Term vars ->
ImpClause -> Core (Either RawImp Clause)
checkClause mult hashit n opts nest env (ImpossibleClause fc lhs)
= do lhs_raw <- lhsInCurrentNS nest lhs
handleUnify
(do autoimp <- isUnboundImplicits
setUnboundImplicits True
(_, lhs) <- bindNames False lhs_raw
setUnboundImplicits autoimp
log 5 $ "Checking " ++ show lhs
logEnv 5 "In env" env
(lhstm, lhstyg) <-
elabTerm n (InLHS mult) opts nest env
(IBindHere fc PATTERN lhs) Nothing
defs <- get Ctxt
lhs <- normaliseHoles defs env lhstm
if !(hasEmptyPat defs env lhs)
then pure (Left lhs_raw)
else throw (ValidCase fc env (Left lhs)))
(\err =>
case err of
ValidCase _ _ _ => throw err
_ => do defs <- get Ctxt
if !(impossibleErrOK defs err)
then pure (Left lhs_raw)
else throw (ValidCase fc env (Right err)))
checkClause {vars} mult hashit n opts nest env (PatClause fc lhs_in rhs)
= do (_, (vars' ** (sub', env', nest', lhstm', lhsty'))) <-
checkLHS mult hashit n opts nest env fc lhs_in
let rhsMode = case mult of
Rig0 => InType
_ => InExpr
log 5 $ "Checking RHS " ++ show rhs
logEnv 5 "In env" env'
rhstm <- wrapError (InRHS fc !(getFullName (Resolved n))) $
checkTermSub n rhsMode opts nest' env' env sub' rhs (gnf env' lhsty')
clearHoleLHS
logTerm 3 "RHS term" rhstm
when hashit $
do addHash lhstm'
addHash rhstm
-- If the rhs is a hole, record the lhs in the metadata because we
-- might want to split it interactively
case rhstm of
Meta _ _ _ _ =>
addLHS (getFC lhs_in) (length env) env' lhstm'
_ => pure ()
pure (Right (MkClause env' lhstm' rhstm))
-- TODO: (to decide) With is complicated. Move this into its own module?
checkClause {vars} mult hashit n opts nest env (WithClause fc lhs_in wval_raw cs)
= do (lhs, (vars' ** (sub', env', nest', lhspat, reqty))) <-
checkLHS mult hashit n opts nest env fc lhs_in
let wmode
= case mult of
Rig0 => InType -- treat as used in type only
_ => InExpr
(wval, gwvalTy) <- wrapError (InRHS fc !(getFullName (Resolved n))) $
elabTermSub n wmode opts nest' env' env sub' wval_raw Nothing
clearHoleLHS
logTerm 5 "With value" wval
logTerm 3 "Required type" reqty
wvalTy <- getTerm gwvalTy
defs <- get Ctxt
wval <- normaliseHoles defs env' wval
wvalTy <- normaliseHoles defs env' wvalTy
let (wevars ** withSub) = keepOldEnv sub' (snd (findSubEnv env' wval))
logTerm 5 "With value type" wvalTy
log 5 $ "Using vars " ++ show wevars
let Just wval = shrinkTerm wval withSub
| Nothing => throw (InternalError "Impossible happened: With abstraction failure #1")
let Just wvalTy = shrinkTerm wvalTy withSub
| Nothing => throw (InternalError "Impossible happened: With abstraction failure #2")
-- Should the env be normalised too? If the following 'impossible'
-- error is ever thrown, that might be the cause!
let Just wvalEnv = shrinkEnv env' withSub
| Nothing => throw (InternalError "Impossible happened: With abstraction failure #3")
-- Abstracting over 'wval' in the scope of bNotReq in order
-- to get the 'magic with' behaviour
let wargn = MN "warg" 0
let scenv = Pi RigW Explicit wvalTy :: wvalEnv
let bnr = bindNotReq fc 0 env' withSub [] reqty
let notreqns = fst bnr
let notreqty = snd bnr
wtyScope <- replace defs scenv !(nf defs scenv (weaken wval))
(Local fc (Just False) _ First)
!(nf defs scenv
(weaken {n=wargn} notreqty))
let bNotReq = Bind fc wargn (Pi RigW Explicit wvalTy) wtyScope
let Just (reqns, envns, wtype) = bindReq fc env' withSub [] bNotReq
| Nothing => throw (InternalError "Impossible happened: With abstraction failure #4")
-- list of argument names - 'Just' means we need to match the name
-- in the with clauses to find out what the pattern should be.
-- 'Nothing' means it's the with pattern (so wargn)
let wargNames
= map Just reqns ++
Nothing :: map Just notreqns
logTerm 3 "With function type" wtype
log 5 $ "Argument names " ++ show wargNames
wname <- genWithName n
widx <- addDef wname (newDef fc wname mult vars wtype Private None)
let rhs_in = apply (IVar fc wname)
(map (IVar fc) envns ++
map (maybe wval_raw (\pn => IVar fc (snd pn))) wargNames)
log 3 $ "Applying to with argument " ++ show rhs_in
rhs <- wrapError (InRHS fc !(getFullName (Resolved n))) $
checkTermSub n wmode opts nest' env' env sub' rhs_in
(gnf env' reqty)
-- Generate new clauses by rewriting the matched arguments
cs' <- traverse (mkClauseWith 1 wname wargNames lhs) cs
log 3 $ "With clauses: " ++ show cs'
-- Elaborate the new definition here
nestname <- applyEnv env wname
let nest'' = record { names $= (nestname ::) } nest
let wdef = IDef fc wname cs'
processDecl [] nest'' env wdef
pure (Right (MkClause env' lhspat rhs))
where
-- If it's 'KeepCons/SubRefl' in 'outprf', that means it was in the outer
-- environment so we need to keep it in the same place in the 'with'
-- function. Hence, turn it to KeepCons whatever
keepOldEnv : (outprf : SubVars outer vs) -> SubVars vs' vs ->
(vs'' : List Name ** SubVars vs'' vs)
keepOldEnv {vs} SubRefl p = (vs ** SubRefl)
keepOldEnv {vs} p SubRefl = (vs ** SubRefl)
keepOldEnv (DropCons p) (DropCons p')
= let (_ ** rest) = keepOldEnv p p' in
(_ ** DropCons rest)
keepOldEnv (DropCons p) (KeepCons p')
= let (_ ** rest) = keepOldEnv p p' in
(_ ** KeepCons rest)
keepOldEnv (KeepCons p) (DropCons p')
= let (_ ** rest) = keepOldEnv p p' in
(_ ** KeepCons rest)
keepOldEnv (KeepCons p) (KeepCons p')
= let (_ ** rest) = keepOldEnv p p' in
(_ ** KeepCons rest)
-- Rewrite the clauses in the block to use an updated LHS.
-- 'drop' is the number of additional with arguments we expect (i.e.
-- the things to drop from the end before matching LHSs)
mkClauseWith : (drop : Nat) -> Name -> List (Maybe (PiInfo RawImp, Name)) ->
RawImp -> ImpClause ->
Core ImpClause
mkClauseWith drop wname wargnames lhs (PatClause ploc patlhs rhs)
= do newlhs <- getNewLHS ploc drop nest wname wargnames lhs patlhs
newrhs <- withRHS ploc drop wname wargnames rhs lhs
pure (PatClause ploc newlhs newrhs)
mkClauseWith drop wname wargnames lhs (WithClause ploc patlhs rhs ws)
= do newlhs <- getNewLHS ploc drop nest wname wargnames lhs patlhs
newrhs <- withRHS ploc drop wname wargnames rhs lhs
ws' <- traverse (mkClauseWith (S drop) wname wargnames lhs) ws
pure (WithClause ploc newlhs newrhs ws')
mkClauseWith drop wname wargnames lhs (ImpossibleClause ploc patlhs)
= do newlhs <- getNewLHS ploc drop nest wname wargnames lhs patlhs
pure (ImpossibleClause ploc newlhs)
nameListEq : (xs : List Name) -> (ys : List Name) -> Maybe (xs = ys)
nameListEq [] [] = Just Refl
nameListEq (x :: xs) (y :: ys) with (nameEq x y)
nameListEq (x :: xs) (x :: ys) | (Just Refl) with (nameListEq xs ys)
nameListEq (x :: xs) (x :: xs) | (Just Refl) | Just Refl= Just Refl
nameListEq (x :: xs) (x :: ys) | (Just Refl) | Nothing = Nothing
nameListEq (x :: xs) (y :: ys) | Nothing = Nothing
nameListEq _ _ = Nothing
-- Compile run time case trees for the given name
mkRunTime : {auto c : Ref Ctxt Defs} ->
{auto u : Ref UST UState} ->
Name -> Core ()
mkRunTime n
= do defs <- get Ctxt
Just gdef <- lookupCtxtExact n (gamma defs)
| _ => pure ()
let PMDef r cargs tree_ct _ pats = definition gdef
| _ => pure () -- not a function definition
let ty = type gdef
(rargs ** tree_rt) <- getPMDef (location gdef) RunTime n ty
!(traverse (toClause (location gdef)) pats)
let Just Refl = nameListEq cargs rargs
| Nothing => throw (InternalError "WAT")
addDef n (record { definition = PMDef r cargs tree_ct tree_rt pats
} gdef)
pure ()
where
toClause : FC -> (vars ** (Env Term vars, Term vars, Term vars)) ->
Core Clause
toClause fc (_ ** (env, lhs, rhs))
= do rhs_erased <- linearCheck fc Rig1 True env rhs
pure $ MkClause env lhs rhs_erased
compileRunTime : {auto c : Ref Ctxt Defs} ->
{auto u : Ref UST UState} ->
Core ()
compileRunTime
= do defs <- get Ctxt
traverse_ mkRunTime (toCompile defs)
defs <- get Ctxt
put Ctxt (record { toCompile = [] } defs)
-- Calculate references for the given name, and recursively if they haven't
-- been calculated already
calcRefs : {auto c : Ref Ctxt Defs} ->
(aTotal : Name) -> (fn : Name) -> Core ()
calcRefs at fn
= do defs <- get Ctxt
Just gdef <- lookupCtxtExact fn (gamma defs)
| _ => pure ()
let PMDef r cargs tree_ct _ pats = definition gdef
| _ => pure () -- not a function definition
let Nothing = refersToM gdef
| Just _ => pure () -- already done
let metas = getMetas tree_ct
traverse_ addToSave (keys metas)
let refs = addRefs at metas tree_ct
logC 5 (do fulln <- getFullName fn
refns <- traverse getFullName (keys refs)
pure (show fulln ++ " refers to " ++ show refns))
addDef fn (record { refersToM = Just refs } gdef)
traverse_ (calcRefs at) (keys refs)
toPats : Clause -> (vs ** (Env Term vs, Term vs, Term vs))
toPats (MkClause {vars} env lhs rhs)
= (_ ** (env, lhs, rhs))
export
processDef : {auto c : Ref Ctxt Defs} ->
{auto m : Ref MD Metadata} ->
{auto u : Ref UST UState} ->
List ElabOpt -> NestedNames vars -> Env Term vars -> FC ->
Name -> List ImpClause -> Core ()
processDef opts nest env fc n_in cs_in
= do n <- inCurrentNS n_in
defs <- get Ctxt
Just gdef <- lookupCtxtExact n (gamma defs)
| Nothing => throw (NoDeclaration fc n)
let None = definition gdef
| _ => throw (AlreadyDefined fc n)
let ty = type gdef
let hashit = visibility gdef == Public
let mult = if multiplicity gdef == Rig0
then Rig0
else Rig1
nidx <- resolveName n
cs <- traverse (checkClause mult hashit nidx opts nest env) cs_in
let pats = map toPats (rights cs)
(cargs ** tree_ct) <- getPMDef fc CompileTime n ty (rights cs)
logC 2 (do t <- toFullNames tree_ct
pure ("Case tree for " ++ show n ++ ": " ++ show t))
-- Add compile time tree as a placeholder for the runtime tree,
-- but we'll rebuild that in a later pass once all the case
-- blocks etc are resolved
addDef (Resolved nidx)
(record { definition = PMDef defaultPI cargs tree_ct tree_ct pats
} gdef)
let rmetas = getMetas tree_ct
traverse_ addToSave (keys rmetas)
let tymetas = getMetas (type gdef)
traverse_ addToSave (keys tymetas)
addToSave n
log 10 $ "Saving from " ++ show n ++ ": " ++ show (keys rmetas)
-- Flag this name as one which needs compiling
defs <- get Ctxt
put Ctxt (record { toCompile $= (n ::) } defs)
when (not (InCase `elem` opts)) $
do atotal <- toResolvedNames (NS ["Builtin"] (UN "assert_total"))
calcRefs atotal (Resolved nidx)
sc <- calculateSizeChange fc n
setSizeChange fc n sc
md <- get MD -- don't need the metadata collected on the coverage check
cov <- checkCoverage nidx ty mult cs
setCovering fc n cov
put MD md
-- If we're not in a case tree, compile all the outstanding case
-- trees. TODO: Take into account coverage, and add error cases
-- if we're not covering.
when (not (elem InCase opts)) $
compileRunTime
where
simplePat : Term vars -> Bool
simplePat (Local _ _ _ _) = True
simplePat (Erased _ _) = True
simplePat (As _ _ _ p) = simplePat p
simplePat _ = False
-- Is the clause returned from 'checkClause' a catch all clause, i.e.
-- one where all the arguments are variables? If so, no need to do the
-- (potentially expensive) coverage check
catchAll : Clause -> Bool
catchAll (MkClause env lhs _)
= all simplePat (getArgs lhs)
-- Return 'Nothing' if the clause is impossible, otherwise return the
-- original
checkImpossible : Int -> RigCount -> ClosedTerm ->
Core (Maybe ClosedTerm)
checkImpossible n mult tm
= do itm <- unelabNoPatvars [] tm
handleUnify
(do ctxt <- get Ctxt
log 3 $ "Checking for impossibility: " ++ show itm
ok <- checkClause mult False n [] (MkNested []) []
(ImpossibleClause fc itm)
put Ctxt ctxt
either (\e => pure Nothing)
(\chktm => pure (Just tm)) ok)
(\err => case err of
WhenUnifying _ env l r err
=> do defs <- get Ctxt
if !(impossibleOK defs !(nf defs env l)
!(nf defs env r))
then pure Nothing
else pure (Just tm)
_ => pure (Just tm))
getClause : {auto c : Ref Ctxt Defs} ->
Either RawImp Clause -> Core (Maybe Clause)
getClause (Left rawlhs)
= catch (do lhsp <- getImpossibleTerm rawlhs
log 3 $ "Generated impossible LHS: " ++ show lhsp
pure $ Just $ MkClause [] lhsp (Erased (getFC rawlhs) True))
(\e => pure Nothing)
getClause (Right c) = pure (Just c)
checkCoverage : Int -> ClosedTerm -> RigCount ->
List (Either RawImp Clause) ->
Core Covering
checkCoverage n ty mult cs
= do covcs' <- traverse getClause cs -- Make stand in LHS for impossible clauses
let covcs = mapMaybe id covcs'
(_ ** ctree) <- getPMDef fc CompileTime (Resolved n) ty covcs
missCase <- if any catchAll covcs
then do log 3 $ "Catch all case in " ++ show n
pure []
else getMissing fc (Resolved n) ctree
logC 3 (do mc <- traverse toFullNames missCase
pure ("Initially missing in " ++
show !(getFullName (Resolved n)) ++ ":\n" ++
showSep "\n" (map show mc)))
missImp <- traverse (checkImpossible n mult) missCase
let miss = mapMaybe id missImp
if isNil miss
then do [] <- getNonCoveringRefs fc (Resolved n)
| ns => toFullNames (NonCoveringCall ns)
pure IsCovering
else pure (MissingCases miss)