quox/lib/Quox/Syntax/Term/Subst.idr

472 lines
15 KiB
Idris

module Quox.Syntax.Term.Subst
import Quox.No
import Quox.Syntax.Term.Base
import Data.SnocVect
%default total
namespace CanQSubst
public export
interface CanQSubst (0 tm : TermLike) where
(//) : {q1, q2 : Nat} -> tm q1 d n -> Lazy (QSubst q1 q2) -> tm q2 d n
||| does the minimal reasonable work:
||| - deletes the closure around an atomic constant like `TYPE`
||| - deletes an identity substitution
||| - composes (lazily) with an existing top-level dim-closure
||| - otherwise, wraps in a new closure
export
CanQSubst Term where
s // Shift SZ = s
TYPE l loc // _ = TYPE l loc
QCloT (SubR s ph) // th = QCloT $ SubR s $ ph .? th
s // th = QCloT $ SubR s th
||| does the minimal reasonable work:
||| - deletes the closure around a term variable
||| - deletes an identity substitution
||| - composes (lazily) with an existing top-level dim-closure
||| - immediately looks up bound variables in a
||| top-level sequence of dimension applications
||| - otherwise, wraps in a new closure
export
CanQSubst Elim where
e // Shift SZ = e
F x u loc // _ = F x u loc -- [todo] q args
B i loc // _ = B i loc
QCloE (SubR e ph) // th = QCloE $ SubR e $ ph .? th
e // th = QCloE $ SubR e th
namespace CanDSubst
public export
interface CanDSubst (0 tm : TermLike) where
(//) : tm q d1 n -> Lazy (DSubst d1 d2) -> tm q d2 n
||| does the minimal reasonable work:
||| - deletes the closure around an atomic constant like `TYPE`
||| - deletes an identity substitution
||| - composes (lazily) with an existing top-level dim-closure
||| - otherwise, wraps in a new closure
export
CanDSubst Term where
s // Shift SZ = s
TYPE l loc // _ = TYPE l loc
DCloT (Sub s ph) // th = DCloT $ Sub s $ ph . th
s // th = DCloT $ Sub s th
private
subDArgs : Elim q d1 n -> DSubst d1 d2 -> Elim q d2 n
subDArgs (DApp f d loc) th = DApp (subDArgs f th) (d // th) loc
subDArgs e th = DCloE $ Sub e th
||| does the minimal reasonable work:
||| - deletes the closure around a term variable
||| - deletes an identity substitution
||| - composes (lazily) with an existing top-level dim-closure
||| - immediately looks up bound variables in a
||| top-level sequence of dimension applications
||| - otherwise, wraps in a new closure
export
CanDSubst Elim where
e // Shift SZ = e
F x u loc // _ = F x u loc
B i loc // _ = B i loc
e@(DApp {}) // th = subDArgs e th
DCloE (Sub e ph) // th = DCloE $ Sub e $ ph . th
e // th = DCloE $ Sub e th
namespace QSubst.ScopeTermN
export %inline
(//) : {q1, q2 : Nat} -> ScopeTermN s q1 d n -> Lazy (QSubst q1 q2) ->
ScopeTermN s q2 d n
S ns (Y body) // th = S ns $ Y $ body // th
S ns (N body) // th = S ns $ N $ body // th
namespace DSubst.ScopeTermN
export %inline
(//) : ScopeTermN s q d1 n -> Lazy (DSubst d1 d2) ->
ScopeTermN s q d2 n
S ns (Y body) // th = S ns $ Y $ body // th
S ns (N body) // th = S ns $ N $ body // th
namespace QSubst.DScopeTermN
export %inline
(//) : {q1, q2 : Nat} -> DScopeTermN s q1 d n -> Lazy (QSubst q1 q2) ->
DScopeTermN s q2 d n
S ns (Y body) // th = S ns $ Y $ body // th
S ns (N body) // th = S ns $ N $ body // th
namespace DSubst.DScopeTermN
export %inline
(//) : {s : Nat} ->
DScopeTermN s q d1 n -> Lazy (DSubst d1 d2) ->
DScopeTermN s q d2 n
S ns (Y body) // th = S ns $ Y $ body // pushN s (locs $ toList' ns) th
S ns (N body) // th = S ns $ N $ body // th
export %inline
FromVarR (Elim q d) where fromVarR = B
export %inline
FromVar (Elim q d) where fromVar = B; fromVarSame _ _ = Refl
export %inline
FromVarR (Term q d) where fromVarR = E .: fromVarR
export %inline
FromVar (Term q d) where fromVar = E .: fromVar; fromVarSame _ _ = Refl
export
CanSubstSelf (Elim q d)
private
tsubstElim : Elim q d from -> Lazy (TSubst q d from to) -> Elim q d to
tsubstElim (F x u loc) _ = F x u loc
tsubstElim (B i loc) th = get th i loc
tsubstElim (CloE (Sub e ph)) th = assert_total CloE $ Sub e $ ph . th
tsubstElim e th =
case force th of
Shift SZ => e
th => CloE $ Sub e th
||| does the minimal reasonable work:
||| - deletes the closure around a *free* name
||| - deletes an identity substitution
||| - composes (lazily) with an existing top-level closure
||| - immediately looks up a bound variable
||| - otherwise, wraps in a new closure
CanSubstSelfR (Elim q d) where (//?) = tsubstElim
export
CanSubstSelf (Elim q d) where (//) = tsubstElim; substSame _ _ = Refl
namespace CanTSubst
public export
interface CanTSubst (0 tm : TermLike) where
(//) : tm q d n1 -> Lazy (TSubst q d n1 n2) -> tm q d n2
||| does the minimal reasonable work:
||| - deletes the closure around an atomic constant like `TYPE`
||| - deletes an identity substitution
||| - composes (lazily) with an existing top-level closure
||| - goes inside `E` in case it is a simple variable or something
||| - otherwise, wraps in a new closure
export
CanTSubst Term where
TYPE l loc // _ = TYPE l loc
E e // th = E $ e // th
CloT (Sub s ph) // th = CloT $ Sub s $ ph . th
s // th = case force th of
Shift SZ => s
th => CloT $ Sub s th
namespace ScopeTermN
export %inline
(//) : {s : Nat} ->
ScopeTermN s q d n1 -> Lazy (TSubst q d n1 n2) ->
ScopeTermN s q d n2
S ns (Y body) // th = S ns $ Y $ body // pushN s (locs $ toList' ns) th
S ns (N body) // th = S ns $ N $ body // th
namespace DScopeTermN
export %inline
(//) : {s : Nat} ->
DScopeTermN s q d n1 -> Lazy (TSubst q d n1 n2) ->
DScopeTermN s q d n2
S ns (Y body) // th = S ns $ Y $ body // map (// shift s) th
S ns (N body) // th = S ns $ N $ body // th
export %inline CanShift (Term q d) where s // by = s // Shift by
export %inline CanShift (Elim q d) where e // by = e // Shift by
-- -- from is not accessible in this context
-- export %inline CanShift (\q => Term q d n) where s // by = s // Shift by
-- export %inline CanShift (\q => Elim q d n) where e // by = e // Shift by
export %inline CanShift (\d => Term q d n) where s // by = s // Shift by
export %inline CanShift (\d => Elim q d n) where e // by = e // Shift by
export %inline
{s : Nat} -> CanShift (ScopeTermN s q d) where
b // by = b // Shift by
export %inline
comp : {q1, q2 : Nat} ->
QSubst q1 q2 -> DSubst d1 d2 ->
TSubst q1 d1 n1 mid -> TSubst q2 d2 mid n2 -> TSubst q2 d2 n1 n2
comp th ph ps ps' = map (\t => t // th // ph) ps . ps'
-- export %inline
-- compD : DSubst d1 d2 -> TSubst q d1 n1 mid ->
-- TSubst q d2 mid n2 -> TSubst q d2 n1 n2
-- compD th ps ph = map (// th) ps . ph
-- export %inline
-- compQ : {q1, q2 : Nat} -> QSubst q1 q2 -> TSubst q1 d n1 mid ->
-- TSubst q2 d mid n2 -> TSubst q2 d n1 n2
-- compQ th ps ph = map (// th) ps . ph
public export %inline
dweakT : (by : Nat) -> Term q d n -> Term q (by + d) n
dweakT by t = t // shift by
public export %inline
dweakS : (by : Nat) -> ScopeTermN s q d n -> ScopeTermN s q (by + d) n
dweakS by t = t // shift by
public export %inline
dweakDS : {s : Nat} -> (by : Nat) ->
DScopeTermN s q d n -> DScopeTermN s q (by + d) n
dweakDS by t = t // shift by
public export %inline
dweakE : (by : Nat) -> Elim q d n -> Elim q (by + d) n
dweakE by t = t // shift by
public export %inline
weakT : (by : Nat) -> Term q d n -> Term q d (by + n)
weakT by t = t // shift by
public export %inline
weakS : {s : Nat} -> (by : Nat) ->
ScopeTermN s q d n -> ScopeTermN s q d (by + n)
weakS by t = t // shift by
public export %inline
weakDS : {s : Nat} -> (by : Nat) ->
DScopeTermN s q d n -> DScopeTermN s q d (by + n)
weakDS by t = t // shift by
public export %inline
weakE : (by : Nat) -> Elim q d n -> Elim q d (by + n)
weakE by t = t // shift by
-- no weakQ etc because no first-class binder to push under
parameters {auto _ : CanShift f} {s : Nat}
export %inline
getTerm : ScopedBody s f n -> f (s + n)
getTerm (Y b) = b
getTerm (N b) = b // fromNat s
export %inline
(.term) : Scoped s f n -> f (s + n)
t.term = getTerm t.body
namespace ScopeTermBody
export %inline
getTerm0 : ScopedBody 0 f n -> f n
getTerm0 (Y b) = b
getTerm0 (N b) = b
namespace ScopeTermN
export %inline
(.term0) : Scoped 0 f n -> f n
t.term0 = getTerm0 t.body
export %inline
subN : ScopeTermN s q d n -> SnocVect s (Elim q d n) -> Term q d n
subN (S _ (Y body)) es = body // fromSnocVect es
subN (S _ (N body)) _ = body
export %inline
sub1 : ScopeTerm q d n -> Elim q d n -> Term q d n
sub1 t e = subN t [< e]
export %inline
dsubN : DScopeTermN s q d n -> SnocVect s (Dim d) -> Term q d n
dsubN (S _ (Y body)) ps = body // fromSnocVect ps
dsubN (S _ (N body)) _ = body
export %inline
dsub1 : DScopeTerm q d n -> Dim d -> Term q d n
dsub1 t p = dsubN t [< p]
public export %inline
(.zero) : (body : DScopeTerm q d n) -> {default body.loc loc : Loc} ->
Term q d n
body.zero = dsub1 body $ K Zero loc
public export %inline
(.one) : (body : DScopeTerm q d n) -> {default body.loc loc : Loc} ->
Term q d n
body.one = dsub1 body $ K One loc
public export
0 CloTest : TermLike -> Type
CloTest tm = forall q, d, n. tm q d n -> Bool
public export
interface PushSubsts (0 tm : TermLike) (0 isClo : CloTest tm) | tm where
pushSubstsWith : {q1, q2 : Nat} ->
QSubst q1 q2 -> DSubst d1 d2 -> TSubst q2 d2 n1 n2 ->
tm q1 d1 n1 -> Subset (tm q2 d2 n2) (No . isClo)
public export
0 NotClo : {isClo : CloTest tm} -> PushSubsts tm isClo => Pred (tm q d n)
NotClo = No . isClo
public export
0 NonClo : (tm : TermLike) -> {isClo : CloTest tm} ->
PushSubsts tm isClo => TermLike
NonClo tm q d n = Subset (tm q d n) NotClo
public export %inline
nclo : {isClo : CloTest tm} -> (0 _ : PushSubsts tm isClo) =>
(t : tm q d n) -> (0 nc : NotClo t) => NonClo tm q d n
nclo t = Element t nc
parameters {0 isClo : CloTest tm} {auto _ : PushSubsts tm isClo}
||| if the input term has any top-level closures, push them under one layer of
||| syntax
export %inline
pushSubsts : {q : Nat} -> tm q d n -> NonClo tm q d n
pushSubsts s = pushSubstsWith id id id s
export %inline
pushSubstsWith' : {q1, q2 : Nat} ->
QSubst q1 q2 -> DSubst d1 d2 -> TSubst q2 d2 n1 n2 ->
tm q1 d1 n1 -> tm q2 d2 n2
pushSubstsWith' th ph ps x = fst $ pushSubstsWith th ph ps x
export %inline
pushSubsts' : {q : Nat} -> tm q d n -> tm q d n
pushSubsts' s = fst $ pushSubsts s
mutual
public export
isCloT : CloTest Term
isCloT (CloT {}) = True
isCloT (DCloT {}) = True
isCloT (QCloT {}) = True
isCloT (E e) = isCloE e
isCloT _ = False
public export
isCloE : CloTest Elim
isCloE (CloE {}) = True
isCloE (DCloE {}) = True
isCloE (QCloE {}) = True
isCloE _ = False
export
PushSubsts Elim Subst.isCloE where
pushSubstsWith th ph ps (F x u loc) =
nclo $ F x u loc
pushSubstsWith th ph ps (B i loc) =
let res = get ps i loc in
case nchoose $ isCloE res of
Left yes => assert_total pushSubsts res
Right no => Element res no
pushSubstsWith th ph ps (App f s loc) =
nclo $ App (f // th // ph // ps) (s // th // ph // ps) loc
pushSubstsWith th ph ps (CasePair pi p r b loc) =
nclo $ CasePair (pi //? th)
(p // th // ph // ps)
(r // th // ph // ps)
(b // th // ph // ps) loc
pushSubstsWith th ph ps (Fst pair loc) =
nclo $ Fst (pair // th // ph // ps) loc
pushSubstsWith th ph ps (Snd pair loc) =
nclo $ Snd (pair // th // ph // ps) loc
pushSubstsWith th ph ps (CaseEnum pi t r arms loc) =
nclo $ CaseEnum (pi //? th)
(t // th // ph // ps)
(r // th // ph // ps)
(map (\b => b // th // ph // ps) arms) loc
pushSubstsWith th ph ps (CaseNat pi pi' n r z s loc) =
nclo $ CaseNat (pi //? th) (pi' //? th)
(n // th // ph // ps)
(r // th // ph // ps)
(z // th // ph // ps)
(s // th // ph // ps) loc
pushSubstsWith th ph ps (CaseBox pi x r b loc) =
nclo $ CaseBox (pi //? th)
(x // th // ph // ps)
(r // th // ph // ps)
(b // th // ph // ps) loc
pushSubstsWith th ph ps (DApp f d loc) =
nclo $ DApp (f // th // ph // ps) (d // ph) loc
pushSubstsWith th ph ps (Ann s a loc) =
nclo $ Ann (s // th // ph // ps) (a // th // ph // ps) loc
pushSubstsWith th ph ps (Coe ty p q val loc) =
nclo $ Coe
(ty // th // ph // ps)
(p // ph) (q // ph)
(val // th // ph // ps) loc
pushSubstsWith th ph ps (Comp ty p q val r zero one loc) =
nclo $ Comp (ty // th // ph // ps) (p // ph) (q // ph)
(val // th // ph // ps) (r // ph)
(zero // th // ph // ps) (one // th // ph // ps) loc
pushSubstsWith th ph ps (TypeCase ty ret arms def loc) =
nclo $ TypeCase (ty // th // ph // ps) (ret // th // ph // ps)
(map (\t => t // th // ph // ps) arms) (def // th // ph // ps) loc
pushSubstsWith th ph ps (CloE (Sub e ps')) =
pushSubstsWith th ph (comp th ph ps' ps) e
pushSubstsWith th ph ps (DCloE (Sub e ph')) =
pushSubstsWith th (ph' . ph) ps e
pushSubstsWith th ph ps (QCloE (SubR e th')) =
pushSubstsWith (th' .? th) ph ps e
export
PushSubsts Term Subst.isCloT where
pushSubstsWith th ph ps (TYPE l loc) =
nclo $ TYPE l loc
pushSubstsWith _ _ _ (IOState loc) =
nclo $ IOState loc
pushSubstsWith th ph ps (Pi qty a body loc) =
nclo $ Pi (qty //? th)
(a // th // ph // ps)
(body // th // ph // ps) loc
pushSubstsWith th ph ps (Lam body loc) =
nclo $ Lam (body // th // ph // ps) loc
pushSubstsWith th ph ps (Sig a b loc) =
nclo $ Sig (a // th // ph // ps) (b // th // ph // ps) loc
pushSubstsWith th ph ps (Pair s t loc) =
nclo $ Pair (s // th // ph // ps) (t // th // ph // ps) loc
pushSubstsWith th ph ps (Enum tags loc) =
nclo $ Enum tags loc
pushSubstsWith th ph ps (Tag tag loc) =
nclo $ Tag tag loc
pushSubstsWith th ph ps (Eq ty l r loc) =
nclo $ Eq
(ty // th // ph // ps)
(l // th // ph // ps)
(r // th // ph // ps) loc
pushSubstsWith th ph ps (DLam body loc) =
nclo $ DLam (body // th // ph // ps) loc
pushSubstsWith _ _ _ (NAT loc) =
nclo $ NAT loc
pushSubstsWith _ _ _ (Nat n loc) =
nclo $ Nat n loc
pushSubstsWith th ph ps (Succ n loc) =
nclo $ Succ (n // th // ph // ps) loc
pushSubstsWith _ _ _ (STRING loc) =
nclo $ STRING loc
pushSubstsWith _ _ _ (Str s loc) =
nclo $ Str s loc
pushSubstsWith th ph ps (BOX pi ty loc) =
nclo $ BOX (pi //? th) (ty // th // ph // ps) loc
pushSubstsWith th ph ps (Box val loc) =
nclo $ Box (val // th // ph // ps) loc
pushSubstsWith th ph ps (E e) =
let Element e nc = pushSubstsWith th ph ps e in nclo $ E e
pushSubstsWith th ph ps (Let qty rhs body loc) =
nclo $ Let (qty //? th)
(rhs // th // ph // ps)
(body // th // ph // ps) loc
pushSubstsWith th ph ps (CloT (Sub s ps')) =
pushSubstsWith th ph (comp th ph ps' ps) s
pushSubstsWith th ph ps (DCloT (Sub s ph')) =
pushSubstsWith th (ph' . ph) ps s
pushSubstsWith th ph ps (QCloT (SubR s th')) =
pushSubstsWith (th' .? th) ph ps s