Address a few issues in Combinatory.newt

TODO.md

@@ -6,6 +6,7 @@
 - [x] I've made `{x}` be `{x : _}` instead of `{_ : x}`. Change this.
 - [ ] Remove context lambdas when printing solutions (show names from context)
   - maybe build list of names and strip λ, then call pprint with names
+- [ ] Revisit substitution in case building
 - [ ] Check for shadowing when declaring dcon
 - [ ] Require infix decl before declaring names (helps find bugs)
 - [ ] sugar for typeclasses

newt-vscode/src/extension.ts

@@ -16,7 +16,7 @@ export function activate(context: vscode.ExtensionContext) {
     const config = vscode.workspace.getConfiguration("newt");
     const cmd = config.get<string>("path", "build/exec/newt");
     const command = `${cmd} ${fileName}`;
-    exec(command, { cwd }, (err, stdout, _stderr) => {
+    exec(command, { cwd, maxBuffer: 1024*1024*10 }, (err, stdout, _stderr) => {
       // I think I ignored 1 here because I wanted failure to launch
       if (err && err.code !== 1) {
         vscode.window.showErrorMessage(`newt error: ${err}`);

newt/Combinatory.newt

@@ -49,14 +49,13 @@ data Env : Ctx -> U where
 -- lookup Here (x ::: y) = x
 -- lookup (There i) (x ::: env) = lookup i env
 
-
 lookup2 : {σ : Type} {Γ : Ctx} → Env Γ → Ref σ Γ → Val σ
 lookup2 (x ::: y) Here = x
 lookup2 (x ::: env) (There i) = lookup2 env i
 
 -- TODO MixFix - this was ⟦_⟧
 eval : {Γ : Ctx} {σ : Type} → Term Γ σ → (Env Γ → Val σ)
--- TODO unification error in direct application
+-- there was a unification error in direct application
 eval (App t u) env = (eval t env) (eval u env)
 eval (Lam t) env = \ x => eval t (x ::: env)
 eval (Var i) env = lookup2 env i
@@ -76,8 +75,11 @@ sapp : {Γ : Ctx} {σ τ ρ : Type} {f : _} {x : _} →
   Comb Γ (σ ~> ρ) (\ env y => (f env y) (x env y))
 sapp (CApp K t) I = t
 sapp (CApp K t) (CApp K u) = CApp K (CApp t u)
-sapp (CApp K t) u = ? -- CApp (CApp B t) u
+-- was out of pattern because of unexpanded lets.
+sapp (CApp K t) u = CApp (CApp B t) u
+-- TODO unsolved meta, out of pattern fragment
 sapp t (CApp K u) = ? -- CApp (CApp C t) u
+-- TODO unsolved meta, out of pattern fragment
 sapp t u = ? -- CApp (CApp S t) u
 
 abs : {Γ : Ctx} {σ τ : Type} {f : _} → Comb (σ :: Γ) τ f → Comb Γ (σ ~> τ) (\ env x => f (x ::: env))
@@ -87,11 +89,11 @@ abs I = CApp K I
 abs B = CApp K B
 abs C = CApp K C
 abs (CApp t u) = sapp (abs t) (abs u)
--- -- TODO lookup2 is getting stuck
-abs (CVar Here) = ? -- I
-abs (CVar (There i)) = ? -- CApp K (Var i)
+-- -- TODO lookup2 was getting stuck, needed to bounce the types in a rewritten env.
+abs (CVar Here) = I
+abs (CVar (There i)) = CApp K (CVar i)
 
 translate : {Γ : Ctx} {σ : Type} → (tm : Term Γ σ) → Comb Γ σ (eval tm)
-translate (App t u) = ? -- CApp (translate t) (translate u)
+translate (App t u) = CApp (translate t) (translate u)
 translate (Lam t) = abs (translate t)
 translate (Var i) = CVar i

src/Lib/Elab.idr

@@ -19,8 +19,8 @@ import Lib.Syntax
 -- dom gamma ren
 data Pden = PR Nat Nat (List Nat)
 
-showEnv : Context -> M String
-showEnv ctx =
+showCtx : Context -> M String
+showCtx ctx =
   unlines . reverse <$> go (names ctx) 0 (reverse $ zip ctx.env (toList ctx.types)) []
   where
     isVar : Nat -> Val -> Bool
@@ -195,8 +195,10 @@ solve env m sp t = do
   let l = length env
   debug "meta \{show meta}"
   ren <- invert l sp
+  -- force unlet
+  hack <- quote l t
+  t <- eval env CBN hack
   catchError {e=Error} (do
-
     tm <- rename m ren l t
 
     let tm = lams (length sp) tm
@@ -220,8 +222,6 @@ solve env m sp t = do
         debug "CONSTRAINT3 m\{show ix} \{show sp} =?= \{show t}"
         debug "because \{showError "" err}"
         addConstraint env m sp t)
-        --throwError err)
-
 
 unifySpine : Env -> UnifyMode -> Bool -> SnocList Val -> SnocList Val  -> M UnifyResult
 unifySpine env mode False _ _ = error emptyFC "unify failed at head" -- unreachable now
@@ -277,13 +277,13 @@ unify env mode t u = do
     -- We only want to do this for LHS pattern vars, otherwise, try expanding
     (_, VVar fc k [<], u) => case mode of
       Pattern => pure $ MkResult[(k, u)]
-      Normal => case !(tryEval u) of
+      Normal => case !(tryEval env u) of
         Just v => unify env mode t' v
         Nothing => error fc "Failed to unify \{show t'} and \{show u'}"
 
     (_,t, VVar fc k [<]) => case mode of
       Pattern => pure $ MkResult[(k, t)]
-      Normal => case !(tryEval t) of
+      Normal => case !(tryEval env t) of
         Just v => unify env mode v u'
         Nothing => error fc "Failed to unify \{show t'} and \{show u'}"
 
@@ -301,21 +301,18 @@ unify env mode t u = do
 
     -- REVIEW - consider separate value for DCon/TCon
     (_, VRef fc k def sp,  VRef fc' k' def' sp') =>
-      -- This is a problem for cmp (S x) (S y) =?= cmp x y, when the
-      -- same is an equation in cmp.
-
-      -- if k == k' then do
-      --   debug "unify \{show l} spine at \{k} \{show sp} \{show sp'}"
-      --   unifySpine l (k == k') sp sp'
-      -- else
+      -- unifySpine is a problem for cmp (S x) (S y) =?= cmp x y
         do
-        Nothing <- tryEval t'
-          | Just v => unify env mode v u'
-        Nothing <- tryEval u'
-          | Just v => unify env mode t' v
-        if k == k'
-          then unifySpine env mode (k == k') sp sp'
-          else error fc "vref mismatch \{show t'} \{show u'}"
+        -- catchError {e = Error} (unifySpine env mode (k == k') sp sp') $ \ err => do
+            Nothing <- tryEval env t'
+              | Just v => do
+              debug "tryEval \{show t'} to \{show v}"
+              unify env mode v u'
+            Nothing <- tryEval env u'
+              | Just v => unify env mode t' v
+            if k == k'
+              then unifySpine env mode (k == k') sp sp'
+              else error fc "vref mismatch \{show t'} \{show u'}"
 
     (_, VU _, VU _) => pure neutral
     -- Lennart.newt cursed type references itself
@@ -690,19 +687,21 @@ checkDone : Context -> List (String, Pattern) -> Raw -> Val -> M Tm
 checkDone ctx [] body ty = do
   debug "DONE-> check body \{show body} at \{show ty}"
   -- TODO better dump context function
-  -- debugM $ showEnv ctx
-  -- -- Hack to try to get Combinatory working.
-  -- env' <- for ctx.env $ \ val => do
-  --   ty <- quote (length ctx.env) val
-  --   eval ctx.env CBN ty
-  -- types' <- for ctx.types $ \case
-  --   (nm,ty) =>  do
-  --     nty <- quote (length ctx.env) ty
-  --     ty' <- eval ctx.env CBN nty
-  --     pure (nm, ty')
-  -- let ctx = { env := env', types := types' } ctx
-  -- debug "AFTER"
-  -- debugM $ showEnv ctx
+  debugM $ showCtx ctx
+  -- Hack to try to get Combinatory working
+  -- we're trying to subst in solutions here.
+  env' <- for ctx.env $ \ val => do
+    ty <- quote (length ctx.env) val
+    -- This is not getting vars under lambdas
+    eval ctx.env CBV ty
+  types' <- for ctx.types $ \case
+    (nm,ty) =>  do
+      nty <- quote (length env') ty
+      ty' <- eval env' CBV nty
+      pure (nm, ty')
+  let ctx = { env := env', types := types' } ctx
+  debug "AFTER"
+  debugM $ showCtx ctx
   -- I'm running an eval here to run case statements that are
   -- unblocked by lets in the env. (Tree.newt:cmp)
   -- The case eval code only works in the Tm -> Val case at the moment.
@@ -825,7 +824,7 @@ buildTree ctx prob@(MkProb ((MkClause fc constraints [] expr) :: cs) ty) = do
   case pat of
     PatCon _ _ _ _ => do
       -- expand vars that may be solved, eval top level functions
-      scty' <- unlet ctx.env scty >>= forceType
+      scty' <- unlet ctx.env scty >>= forceType ctx.env
       debug "EXP \{show scty} -> \{show scty'}"
       -- this is per the paper, but it would be nice to coalesce
       -- default cases
@@ -857,7 +856,7 @@ undo ((DoExpr fc tm) :: xs) = pure $ RApp fc (RApp fc (RVar fc "_>>=_") tm Expli
 undo ((DoLet fc nm tm) :: xs) = RLet fc nm (RImplicit fc) tm <$> undo xs
 undo ((DoArrow fc nm tm) :: xs) = pure $ RApp fc (RApp fc (RVar fc "_>>=_") tm Explicit) (RLam fc nm Explicit !(undo xs)) Explicit
 
-check ctx tm ty = case (tm, !(forceType ty)) of
+check ctx tm ty = case (tm, !(forceType ctx.env ty)) of
   (RDo fc stmts, ty) => check ctx !(undo stmts) ty
   (RCase fc rsc alts, ty) => do
     (sc, scty) <- infer ctx rsc

src/Lib/Eval.idr

@@ -38,25 +38,13 @@ vapp (VLam _ _ t) u = t $$ u
 vapp (VVar fc k sp) u = pure $ VVar fc k (sp :< u)
 vapp (VRef fc nm def sp) u = pure $ VRef fc nm def (sp :< u)
 vapp (VMeta fc k sp) u = pure $ VMeta fc k (sp :< u)
-vapp t u = error' "impossible in vapp \{show t} to \{show u}"
+vapp t u = error' "impossible in vapp \{show t} to \{show u}\n"
 
 export
 vappSpine : Val -> SnocList Val -> M Val
 vappSpine t [<] = pure t
 vappSpine t (xs :< x) = vapp !(vappSpine t xs) x
 
-export
-tryEval : Val -> M (Maybe Val)
-tryEval (VRef fc k _ sp) =
-  case lookup k !(get) of
-      Just (MkEntry name ty (Fn tm)) => do
-          vtm <- eval [] CBN tm
-          case !(vappSpine vtm sp) of
-            VCase{} => pure Nothing
-            v => pure $ Just v
-      _ => pure Nothing
-tryEval _ = pure Nothing
-
 
 
 lookupVar : Env -> Nat -> Maybe Val
@@ -81,17 +69,34 @@ unlet env t@(VVar fc k sp) = case lookupVar env k of
         pure t
 unlet env x = pure x
 
+export
+tryEval : Env -> Val -> M (Maybe Val)
+tryEval env (VRef fc k _ sp) =
+  case lookup k !(get) of
+      Just (MkEntry name ty (Fn tm)) =>
+        catchError {e=Error} (
+            do
+            debug "app \{name} to \{show sp}"
+            vtm <- eval [] CBN tm
+            debug "tm is \{pprint [] tm}"
+            case !(vappSpine vtm sp) of
+              VCase{} => pure Nothing
+              v => pure $ Just v)
+            (\ _ => pure Nothing)
+      _ => pure Nothing
+tryEval _ _ = pure Nothing
+
 
 -- Force far enough to compare types
 export
-forceType : Val -> M Val
-forceType (VMeta fc ix sp) = case !(lookupMeta ix) of
+forceType : Env -> Val -> M Val
+forceType env (VMeta fc ix sp) = case !(lookupMeta ix) of
   (Unsolved x k xs _ _ _) => pure (VMeta fc ix sp)
-  (Solved _ k t) => vappSpine t sp >>= forceType
-forceType x = do
-  Just x' <- tryEval x
+  (Solved _ k t) => vappSpine t sp >>= forceType env
+forceType env x = do
+  Just x' <- tryEval env x
     | _ => pure x
-  forceType x'
+  forceType env x'
 
 evalCase : Env -> Mode -> Val -> List CaseAlt -> M (Maybe Val)
 evalCase env mode sc@(VRef _ nm _ sp) (cc@(CaseCons name nms t) :: xs) =
@@ -108,7 +113,7 @@ evalCase env mode sc@(VRef _ nm _ sp) (cc@(CaseCons name nms t) :: xs) =
     go env (arg :: args) (nm :: nms) = go (arg :: env) args nms
     go env args [] = Just <$> vappSpine !(eval env mode t) ([<] <>< args)
     go env [] rest = pure Nothing
--- This is an attempt to handle unlet for
+-- REVIEW - this is handled in the caller already
 evalCase env mode sc@(VVar fc k sp) alts = case lookupVar env k of
     Just tt@(VVar fc' k' sp') => do
         debug "lookup \{show k} is \{show tt}"
@@ -159,7 +164,7 @@ eval env mode tm@(Case fc sc alts) = do
   -- TODO we need to be able to tell eval to expand aggressively here.
   sc' <- eval env mode sc
   sc' <- unlet env sc' -- try to expand lets from pattern matching
-  sc' <- forceType sc'
+  sc' <- forceType env sc'
   pure $ fromMaybe (VCase fc !(eval env mode sc) alts)
                              !(evalCase env mode sc' alts)