start of type stuff

This commit is contained in:
rhiannon morris 2021-12-23 19:05:50 +01:00
parent f363dc3122
commit 88338050fc
2 changed files with 448 additions and 0 deletions

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module Quox.Typechecker
import public Quox.Syntax
import public Quox.Typing
import Quox.Error
import Data.Nat
import Data.SortedMap
import Control.Monad.Reader
import Control.Monad.State
import Syntax.WithProof
%default total
public export
data Error : Type where
ExpectedType : (subj, ty : Term d n) -> Error
UniverseInconsistency : (lo, hi : Universe) -> Error
GlobalNotInScope : Name -> Error
public export
record CheckResult
{0 d, n : Nat}
(0 ctx : WfContext d n)
(0 subj, ty : Term d n)
where
constructor MkCheckResult
tmout, tyout : QOutput n
hasType : HasTypeT {ctx = ctx.ctx, subj, ty, tmout, tyout}
public export
record InferResult
{0 d, n : Nat}
(0 ctx : WfContext d n)
(0 subj : Elim d n)
where
constructor MkInferResult
tmout, tyout : QOutput n
ty : Term d n
hasType : HasTypeE {ctx = ctx.ctx, subj, ty, tmout, tyout}
public export
zeroCtx : Globals -> TyContext 0 0
zeroCtx globals = MkTyContext {globals, dctx = DNil, tctx = [<], qctx = [<]}
public export
zeroWfCtx : Globals -> WfContext 0 0
zeroWfCtx globals = MkWfContext (zeroCtx globals) NIL
public export
Check0 : (globals : Globals) -> (subj, ty : Term 0 0) -> Type
Check0 globals subj ty =
HasTypeT {ctx = zeroCtx globals, subj, ty, tmout = [<], tyout = [<]}
public export
record Infer0 (globals : Globals) (subj : Elim 0 0) where
constructor MkInfer0
ty : Term 0 0
hasType : HasTypeE {ctx = zeroCtx globals, subj, ty, tmout = [<], tyout = [<]}
export
0 isTypeZeroTyout : HasTypeT {ty = TYPE _, tyout, _} -> IsZero tyout
isTypeZeroTyout (TYPE {zty, _}) = zty
isTypeZeroTyout (Pi {zty, _}) = zty
isTypeZeroTyout (PushT {}) = ?isTypeZeroTyout_PushT
parameters {auto _ : MonadThrow Error m} mutual
private
checkUniverse : (lo, hi : Universe) -> m (lo `LT` hi)
checkUniverse lo hi with (lo `isLT` hi)
_ | Yes lt = pure lt
_ | No _ = throw $ UniverseInconsistency {lo, hi}
private
expectType : (subj, ty : Term d n) ->
m (l : Universe ** ty = TYPE l)
expectType _ (TYPE l) = pure (l ** Refl)
expectType subj ty = throw $ ExpectedType {subj, ty}
private
checkType : (ctx : WfContext d n) ->
(l : Universe) -> (ty : Term d n) ->
m (CheckResult ctx (TYPE l) ty)
checkType (MkWfContext {ctx, wf}) l ty = do
(l' ** eq) <- expectType (TYPE l) ty; let Refl = eq
lt <- checkUniverse l l'
let Element _ zprf = zero ctx.qctx
pure $ MkCheckResult {hasType = TYPE {wf, lt, ztm = zprf, zty = zprf}, _}
private
checkPi : (ctx : WfContext d n) ->
(qtm, qty : Qty) ->
(x : Name) ->
(arg : Term d n) ->
(res : Term d (S n)) ->
(ty : Term d n) ->
m (CheckResult ctx (Pi qtm qty x arg res) ty)
checkPi (MkWfContext {ctx, wf}) qtm qty x arg res ty = do
let whole = Pi qtm qty x arg res
(l' ** eq) <- expectType whole ty; let Refl = eq
?checkPi_rhs
private
inferFree : (ctx : WfContext {}) -> (x : Name) -> m (InferResult ctx (F x))
inferFree (MkWfContext {ctx, wf}) x =
case @@ lookup x ctx.globals of
(Just g ** eq) =>
let Element _ zprf = zero ctx.tctx
hasType = F {wf, g, eq, ztm = zprf, zty = zprf}
in
pure $ MkInferResult {hasType, _}
_ => throw $ GlobalNotInScope x
private
inferBound : (ctx : WfContext _ n) -> (i : Var n) -> m (InferResult ctx (B i))
inferBound (MkWfContext {ctx, wf}) i =
pure $ MkInferResult {hasType = B {wf, look = lookup ctx i, eq = Refl}, _}
private
inferAnn : (ctx : WfContext d n) -> (tm, ty : Term d n) ->
m (InferResult ctx (tm :# ty))
inferAnn ctx tm ty = do
ignore $ check ctx ty (TYPE UAny)
MkCheckResult {hasType, _} <- check ctx tm ty
pure $ MkInferResult {hasType = Ann hasType, _}
export
check : (ctx : WfContext d n) -> (subj, ty : Term d n) ->
m (CheckResult ctx subj ty)
check ctx subj ty = case subj of
TYPE l => checkType ctx l ty
Pi qtm qty x arg res => checkPi ctx qtm qty x arg res ty
Lam x body => ?check_rhs_3
E e => ?check_rhs_4
CloT s th => ?check_rhs_5
DCloT s th => ?check_rhs_6
export
infer : (ctx : WfContext d n) -> (subj : Elim d n) ->
m (InferResult ctx subj)
infer ctx subj = case subj of
F x => inferFree ctx x
B i => inferBound ctx i
fun :@ arg => ?infer_rhs_3
tm :# ty => inferAnn ctx tm ty
CloE e th => ?infer_rhs_5
DCloE e th => ?infer_rhs_6
parameters {auto _ : MonadThrow Error m} (globals : Globals)
public export
check0 : (subj, ty : Term 0 0) -> m (Check0 globals subj ty)
check0 subj ty = pure $
case !(check (zeroWfCtx globals) subj ty) of
MkCheckResult [<] [<] prf => prf
public export
infer0 : (subj : Elim 0 0) -> (ty : Term 0 0) -> m (Infer0 globals subj)
infer0 subj ty = pure $
case !(infer (zeroWfCtx globals) subj) of
MkInferResult [<] [<] ty prf => MkInfer0 ty prf

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module Quox.Typing
import public Quox.Syntax
import public Quox.Context
import Data.Nat
import Data.SortedMap
import Control.Monad.Reader
import Control.Monad.State
%default total
public export
data DContext : Nat -> Type where
DNil : DContext 0
DBind : DContext d -> DContext (S d)
DEq : Dim d -> Dim d -> DContext d -> DContext d
public export
TContext : Nat -> Nat -> Type
TContext d = Context (Term d)
public export
QContext : Nat -> Type
QContext = Triangle' Qty
public export
QOutput : Nat -> Type
QOutput = Context' Qty
public export
record Global where
constructor MkGlobal
type, term : forall d, n. Term d n
public export
Globals : Type
Globals = SortedMap Name Global
public export
record TyContext (d, n : Nat) where
constructor MkTyContext
globals : Globals
dctx : DContext d
tctx : TContext d n
qctx : QContext n
%name TyContext ctx
namespace TContext
export
pushD : TContext d n -> TContext (S d) n
pushD tel = map (/// shift 1) tel
namespace TyContext
export
extendTy : Term d n -> QOutput n -> TyContext d n -> TyContext d (S n)
extendTy s rhos = {tctx $= (:< s), qctx $= (:< rhos)}
export
extendDim : TyContext d n -> TyContext (S d) n
extendDim = {dctx $= DBind, tctx $= pushD}
export
eqDim : Dim d -> Dim d -> TyContext d n -> TyContext d n
eqDim p q = {dctx $= DEq p q}
namespace QOutput
export
(+) : QOutput n -> QOutput n -> QOutput n
(+) = zipWith (+)
export
(*) : Qty -> QOutput n -> QOutput n
(*) pi = map (pi *)
namespace Zero
public export
data IsZero : QOutput n -> Type where
LinZ : IsZero [<]
SnocZ : IsZero qctx -> IsZero (qctx :< Zero)
export
isZeroIrrel : {qctx : _} -> (0 _ : IsZero qctx) -> IsZero qctx
isZeroIrrel {qctx = [<]} LinZ = LinZ
isZeroIrrel {qctx = _ :< _} (SnocZ x) = SnocZ $ isZeroIrrel x
export
zero : Context _ n -> Subset (QOutput n) IsZero
zero [<] = Element [<] LinZ
zero (ctx :< _) = let zeroN = zero ctx in
Element (zeroN.fst :< Zero) (SnocZ zeroN.snd)
namespace Only
public export
data IsOnly : QOutput n -> Var n -> Type where
Here : IsZero qctx -> IsOnly (qctx :< One) VZ
There : IsOnly qctx i -> IsOnly (qctx :< Zero) (VS i)
export
isOnlyIrrel : {qctx, i : _} -> (0 _ : IsOnly qctx i) -> IsOnly qctx i
isOnlyIrrel {i = VZ} (Here z) = Here $ isZeroIrrel z
isOnlyIrrel {i = (VS i)} (There o) = There $ isOnlyIrrel o
export
only : Context _ n -> (i : Var n) ->
Subset (QOutput n) (\qctx => IsOnly qctx i)
only (ctx :< _) VZ =
let zeroN = zero ctx in
Element (zeroN.fst :< One) (Here zeroN.snd)
only (ctx :< _) (VS i) =
let onlyN = only ctx i in
Element (onlyN.fst :< Zero) (There onlyN.snd)
namespace Universe
public export
data LT : Universe -> Universe -> Type where
Fin : k `LT` l -> U k `LT` U l
Any : U _ `LT` UAny
export
Uninhabited (UAny `LT` j) where
uninhabited _ impossible
export
isLT : (i, j : Universe) -> Dec (i `LT` j)
isLT (U i) (U j) with (i `isLT` j)
_ | Yes prf = Yes $ Fin prf
_ | No contra = No $ \(Fin prf) => contra prf
isLT (U _) UAny = Yes Any
isLT UAny _ = No uninhabited
namespace Lookup
public export
data IsLookup :
(tctx : TContext d n) ->
(i : Var n) ->
(ty : Term d from) ->
(by : Shift from n) -> Type
where
Here : IsLookup {tctx=(tctx :< ty), i=VZ, ty, by=(SS SZ)}
There : IsLookup {tctx, i, ty, by} ->
IsLookup {tctx=(tctx :< ty'), i=(VS i), ty, by=(SS by)}
public export
record Lookup'
{0 d, n : Nat}
(0 tctx : TContext d n)
(0 qctx : QContext n)
(0 i : Var n)
where
constructor MkLookup
tmout, tyout : QOutput n
type : Term d from
by : Shift from n
0 only : IsOnly tmout i
0 look : IsLookup tctx i type by
public export
lookup' : (tctx : TContext d n) -> (qctx : QContext n) ->
(i : Var n) -> Lookup' tctx qctx i
lookup' tctx@(_ :< _) (_ :< tyout) VZ =
MkLookup {only = (only tctx VZ).snd, look = Here,
tyout = tyout :< Zero, _}
lookup' (tctx :< _) (qctx :< _) (VS i) =
let inner = lookup' tctx qctx i in
MkLookup {only = There inner.only, look = There inner.look,
tyout = inner.tyout :< Zero, _}
public export %inline
Lookup : TyContext d n -> Var n -> Type
Lookup ctx i = Lookup' ctx.tctx ctx.qctx i
public export %inline
lookup : (ctx : TyContext d n) -> (i : Var n) -> Lookup ctx i
lookup ctx = lookup' ctx.tctx ctx.qctx
mutual
public export
data HasTypeT :
{0 d, n : Nat} ->
(ctx : TyContext d n) ->
(subj : Term d n) ->
(ty : Term d n) ->
(tmout, tyout : QOutput n) ->
Type
where
TYPE :
(0 wf : IsWf ctx) ->
(lt : k `LT` l) ->
(0 ztm : IsZero tmout) -> (0 zty : IsZero tyout) ->
HasTypeT {ctx, subj = TYPE k, ty = TYPE l, tmout, tyout}
Pi :
(tyA : HasTypeT {ctx, subj = a, ty = TYPE l, tmout = tmoutA, tyout}) ->
(tyB : HasTypeT {ctx = extendTy a tmoutA ctx, subj = b, ty = TYPE l,
tmout = tmoutB :< qty, tyout = tyout :< Zero}) ->
(0 zty : IsZero tyout) ->
HasTypeT {ctx, subj = Pi qtm qty x a b, ty = TYPE l,
tmout = tmoutA + tmoutB, tyout}
PushT :
(0 eq : ty' = pushSubstsT' ty) ->
(j : HasTypeT {ctx, subj, ty = ty', tmout, tyout}) ->
HasTypeT {ctx, subj, ty, tmout, tyout}
public export
data HasTypeE :
{0 d, n : Nat} ->
(ctx : TyContext d n) ->
(subj : Elim d n) ->
(ty : Term d n) ->
(tmout, tyout : QOutput n) ->
Type
where
F :
(0 wf : IsWf ctx) ->
(g : Global) ->
(0 eq : lookup x ctx.globals = Just g) ->
(0 ztm : IsZero tmout) -> (0 zty : IsZero tyout) ->
HasTypeE {ctx, subj = F x, ty = g.type, tmout, tyout}
B :
{0 ctx : TyContext d n} ->
(0 wf : IsWf ctx) ->
(look : Lookup ctx i) ->
(0 eq : ty = look.type // look.by) ->
HasTypeE {ctx, subj = B i, ty, tmout = look.tmout, tyout = look.tyout}
Ann :
HasTypeT {ctx, subj = tm, ty, tmout, tyout} ->
HasTypeE {ctx, subj = tm :# ty, ty, tmout, tyout}
PushE :
(0 eq : ty' = pushSubstsT' ty) ->
HasTypeE {ctx, subj, ty = ty', tmout, tyout} ->
HasTypeE {ctx, subj, ty, tmout, tyout}
public export
data IsWf' :
(globals : Globals) ->
(dctx : DContext d) ->
(tctx : TContext d n) ->
(qctx : QContext n) -> Type
where
NIL : IsWf' globals dctx [<] [<]
BIND :
IsWf' {globals, dctx, tctx, qctx} ->
HasTypeT {ctx = MkTyContext {globals, dctx, tctx, qctx},
subj, ty = TYPE l, tmout, tyout} ->
IsWf' {globals, dctx, tctx = tctx :< subj, qctx = qctx :< tmout}
public export %inline
IsWf : TyContext d n -> Type
IsWf (MkTyContext {globals, dctx, tctx, qctx}) =
IsWf' {globals, dctx, tctx, qctx}
public export
record WfContext (d, n : Nat) where
constructor MkWfContext
ctx : TyContext d n
0 wf : IsWf ctx
public export
record TypeTerm {0 d, n : Nat} (ctx : TyContext d n) where
constructor MkTypeTerm
term : Term d n
univ : Universe
tmout, tyout : QOutput n
isType : HasTypeT {ctx, subj = term, ty = TYPE univ, tmout, tyout}