refactor TopContext to use a ModContext for the current context

2026-02-21 21:27:54 -08:00
parent 0a5ad3cc9b
commit 34744a8edc
11 changed files with 112 additions and 122 deletions
--- a/src/Commands.newt
+++ b/src/Commands.newt
@@ -28,12 +28,8 @@ decomposeName fn =

 switchModule : FileSource → String → M ModContext
 switchModule repo modns = do
-    addPrimitives
-    modifyTop [ metaCtx := MC emptyMap Nil 0 CheckAll ]
    mod <- processModule emptyFC repo Nil modns
-    -- FIXME keep these in ModContext, drop from TopContext
-    modifyTop [ defs := mod.modDefs; metaCtx := mod.modMetaCtx; ops := mod.ctxOps; imported := mod.modDeps; infos := mod.modInfos; ns := modns; errors := mod.modErrors ]
-    top <- getTop
+    modifyTop [ currentMod := mod; ops := mod.modOps ]
    pure mod

 -- The cheap version of type at point, find the token, lookup in global context
@@ -112,7 +108,7 @@ makeEdits : FC → List QName → Bool → M (List FileEdit)
 makeEdits fc@(MkFC uri (MkBounds sr sc er ec)) names inPlace = do
  cons <- map applyDCon <$> traverse lookupDCon names
  top <- getTop
-  let (Just mod) = lookupMap' top.ns top.modules | _ => pure Nil
+  let (Just mod) = lookupMap' top.currentMod.modName top.modules | _ => pure Nil
  let lines = split mod.modSource "\n"
  let (Just line) = getAt' sr lines | _ => pure Nil
  let cs = unpack line
@@ -171,7 +167,7 @@ getActions : FileSource → String → Int → Int → M (List CodeAction)
 getActions repo modns row col = do
  mod <- switchModule repo modns
  top <- getTop
-  let xx = filter (posInFC row col ∘ getFC) top.infos
+  let xx = filter (posInFC row col ∘ getFC) top.currentMod.modInfos
  putStrLn "Filter got \{show $ length' xx}"
  go Nil $ xx
  where
--- a/src/LSP.newt
+++ b/src/LSP.newt
@@ -1,7 +1,6 @@
 module LSP

 import Prelude
-- TODO pull this into its own file
 import Lib.Common
 import Lib.Eval
 import Lib.Types
@@ -165,7 +164,7 @@ errorToDiag (Postpone fc qn msg) = errorToDiag $ E fc "Postpone \{show qn} \{msg
 getInfos : M (List Json)
 getInfos = do
    top <- getTop
-    go Nil $ listValues $ top.metaCtx.metas
+    go Nil $ listValues $ top.currentMod.modMetaCtx.metas
    where
        go : List Json → List MetaEntry → M (List Json)
        go acc Nil = pure acc
@@ -194,13 +193,12 @@ checkFile fn = unsafePerformIO $ do
        then resetState base
        else pure MkUnit
    (Right (top, json)) <- (do
-        modifyTop [ errors := Nil ]
        putStrLn "processModule"
        _ <- switchModule lspFileSource modName

        -- pull out errors and infos
        top <- getTop
-        let errors = map (errorToDiag) top.errors
+        let errors = map (errorToDiag) top.currentMod.modErrors
        infos <- getInfos
        pure $ infos ++ errors
        ).runM st.topContext
--- a/src/Lib/Compile.newt
+++ b/src/Lib/Compile.newt
@@ -516,8 +516,8 @@ process names = do
 compile : M (List Doc)
 compile = do
  top <- getTop
-  let exports = getExports Nil $ listValues top.defs
-  let mainName = (QN top.ns "main")
+  let exports = getExports Nil $ listValues top.currentMod.modDefs
+  let mainName = (QN top.currentMod.modName "main")
  let main = lookup mainName top
  let todo = case main of
    Nothing => exports
--- a/src/Lib/CompileExp.newt
+++ b/src/Lib/CompileExp.newt
@@ -267,7 +267,7 @@ compileDCon ix (QN _ nm) info arity =

 -- probably want to drop the Ref2 when we can
 defToCExp : {{Ref2 Defs St}} → (QName × Def) -> M (QName × CExp)
-defToCExp (qn, Axiom)      = pure (qn, CErased)
+defToCExp (qn, Axiom)      = error emptyFC "\{show qn} is Axiom" -- pure (qn, CErased)
 defToCExp (qn, (PrimOp _)) = (_,_ qn) <$> compilePop qn
 defToCExp (qn, DCon ix info arity _)   = pure (qn, compileDCon ix qn info arity)
 -- We're not using these are runtime at the moment, no typecase
--- a/src/Lib/Elab.newt
+++ b/src/Lib/Elab.newt
@@ -119,7 +119,10 @@ isCandidate _ _ = False

 setMetaMode : MetaMode → M Unit
 -- ideally we would support dotted paths like metaCtx.mcmode := CheckFirst
-setMetaMode mcmode = modifyTop [ metaCtx $= [mcmode := mcmode] ]
+setMetaMode mcmode = modifyTop [ currentMod $= [modMetaCtx $= [mcmode := mcmode] ] ]
+
+setMetaContext : MetaContext → M Unit
+setMetaContext mc = modifyTop [ currentMod $= [ modMetaCtx := mc ]]

 findMatches : Context -> Val -> List (QName × Tm) -> M (List QName)
 findMatches ctx ty Nil = pure Nil
@@ -129,7 +132,7 @@ findMatches ctx ty ((name, type) :: xs) = do

  top <- getTop
  -- save context
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  catchError (do
      -- TODO sort out the FC here
      let fc = getFC ty
@@ -140,11 +143,11 @@ findMatches ctx ty ((name, type) :: xs) = do
      setMetaMode CheckFirst
      tm <- check ctx (RVar fc nm) ty
      debug $ \ _ => "Found \{rpprint Nil tm} for \{show ty}"
-      modifyTop [ metaCtx := mc ]
+      setMetaContext mc
      (_::_ name) <$> findMatches ctx ty xs)
    (\ err => do
      debug $ \ _ => "No match \{show ty} \{rpprint Nil type} \{showError "" err}"
-      modifyTop [ metaCtx := mc ]
+      setMetaContext mc
      findMatches ctx ty xs)

 contextMatches : Context -> Val -> M (List (Tm × Val))
@@ -156,17 +159,17 @@ contextMatches ctx ty = go (zip ctx.env ctx.types)
      type <- quote ctx.lvl vty
      let (True) = isCandidate ty type | False => go xs
      top <- getTop
-      let mc = top.metaCtx
+      let mc = top.currentMod.modMetaCtx
      catchError(do
          debug $ \ _ => "TRY context \{nm} : \{rpprint (names ctx) type} for \{show ty}"
          unifyCatch (getFC ty) ctx ty vty
-          let mc' = top.metaCtx
-          modifyTop [ metaCtx := mc]
+          let mc' = top.currentMod.modMetaCtx
+          setMetaContext mc
          tm <- quote ctx.lvl tm
          (_::_ (tm, vty)) <$> go xs)
        (\ err => do
          debug $ \ _ => "No match \{show ty} \{rpprint (names ctx) type} \{showError "" err}"
-          modifyTop [ metaCtx := mc]
+          setMetaContext mc
          go xs)

 getArity : Tm -> List Quant
@@ -229,7 +232,7 @@ trySolveAuto _ = pure False
 solveAutos : M Unit
 solveAutos = do
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  let autos = filter isAuto $ mapMaybe (flip lookupMap' mc.metas) mc.autos
  res <- run autos
  -- If anything is solved, we try again from the top
@@ -248,13 +251,13 @@ solveAutos = do
 updateMeta : QName -> (MetaEntry -> M MetaEntry) -> M Unit
 updateMeta ix f = do
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  let (Just me) = lookupMap' ix mc.metas | Nothing => pure MkUnit
  me <- f me
  let autos = case me of
    Solved _ _ _ => filter (_/=_ ix) mc.autos
    _ => mc.autos
-  modifyTop [ metaCtx := MC (updateMap ix me mc.metas) autos mc.next mc.mcmode ]
+  setMetaContext $ [metas $= updateMap ix me; autos := autos] mc

 -- Try to solve autos that reference the meta ix
 checkAutos : QName -> List QName -> M Unit
@@ -278,7 +281,7 @@ checkAutos ix (_ :: rest) = checkAutos ix rest
 addConstraint : Env -> QName -> SnocList Val -> Val -> M Unit
 addConstraint env ix sp tm = do
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  let (CheckAll) = mc.mcmode | _ => pure MkUnit
  updateMeta ix $ \case
    (Unsolved pos k a b c cons) => do
@@ -373,7 +376,7 @@ ctx.boundNames = map snd $ filter (\x => fst x == Bound) $ zip ctx.bds (map fst
 maybeCheck : M Unit -> M Unit
 maybeCheck action = do
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  case mc.mcmode of
    CheckAll => action
    CheckFirst => do
@@ -426,7 +429,7 @@ solve env m sp t = do
          unify env UNormal val rhs
      -- check any autos
      top <- getTop
-      let mc = top.metaCtx
+      let mc = top.currentMod.modMetaCtx
      let (CheckAll) = mc.mcmode | _ => pure MkUnit
      debug $ \ _ => "check autos depending on \{show ix} \{debugStr mc.mcmode}"
      checkAutos ix mc.autos
@@ -617,16 +620,17 @@ unifyCatch fc ctx ty' ty = do
 freshMeta : Context -> FC -> Val -> MetaKind -> M Tm
 freshMeta ctx fc ty kind = do
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  debug $ \ _ => "fresh meta \{show mc.next} : \{show ty} (\{show kind})"
  -- need the ns here
  -- we were fudging this for v1
-  let qn = QN top.ns "$m\{show mc.next}"
+  let qn = QN top.currentMod.modName "$m\{show mc.next}"
  let newmeta = Unsolved fc qn ctx ty kind Nil
  let autos = case kind of
      AutoSolve => qn :: mc.autos
      _ => mc.autos
-  modifyTop [metaCtx := MC (updateMap qn newmeta mc.metas) autos (1 + mc.next) mc.mcmode ]
+  setMetaContext $ [ metas $= updateMap qn newmeta; autos := autos; next $= 1 +] mc
+
  -- I tried checking Auto immediately if CheckAll, but there isn't enough information yet.
  pure $ applyBDs 0 (Meta fc qn) ctx.bds
  where
--- a/src/Lib/ProcessDecl.newt
+++ b/src/Lib/ProcessDecl.newt
@@ -51,7 +51,6 @@ logMetas (Unsolved fc k ctx ty User cons :: rest) = do
 logMetas (Unsolved fc k ctx ty kind cons :: rest) = do
      ty' <- forceMeta ty
      tm <- quote ctx.lvl ty'
-      -- FIXME in Combinatory.newt, the val doesn't match environment?
      let msg = "Unsolved meta \{show k} \{show kind} type \{render 90 $ pprint (names ctx) tm} \{show $ length' cons} constraints"
      msgs <- for cons $ \case
        (MkMc fc env sp val) => do
@@ -69,7 +68,7 @@ logMetas (Unsolved fc k ctx ty kind cons :: rest) = do
          pure ("  \{show $ length' matches} Solutions: \{show matches}" :: Nil)

        _ => pure Nil
-      -- info fc $ unlines ((msg :: Nil) ++ msgs ++ sols)
+
      addError $ E fc $ unlines ((msg :: Nil) ++ msgs ++ sols)
      logMetas rest

@@ -95,7 +94,7 @@ impTele tele = map foo tele
 checkAlreadyDef : FC → Name → M Unit
 checkAlreadyDef fc nm = do
  top <- getTop
-  case lookup (QN top.ns nm) top of
+  case lookup (QN top.currentMod.modName nm) top of
    Nothing => pure MkUnit
    Just entry => error fc "\{show nm} is already defined at \{show entry.fc}"

@@ -158,7 +157,7 @@ processDef ns fc nm clauses = do
  log 1 $ \ _ => "-----"
  log 1 $ \ _ => "Def \{show nm}"
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  let (Just entry) = lookup (QN ns nm) top
    | Nothing => throwError $ E fc "No declaration for \{nm}"
  let (MkEntry fc name ty Axiom _) = entry
@@ -436,7 +435,7 @@ processData ns fc (nameFC, nm) ty cons = do
  log 1 $ \ _ => "-----"
  log 1 $ \ _ => "Data \{nm}"
  top <- getTop
-  let mc = top.metaCtx
+  let mc = top.currentMod.modMetaCtx
  tyty <- check (mkCtx fc) ty (VU fc)
  case lookup (QN ns nm) top of
    Just (MkEntry _ name type Axiom _) => do
--- a/src/Lib/ProcessModule.newt
+++ b/src/Lib/ProcessModule.newt
@@ -16,21 +16,14 @@ import Lib.Elab
 -- declare internal primitives
 addPrimitives : M ModContext
 addPrimitives = do
+  modifyTop [ currentMod := emptyModCtx "Prim" ""; hints := emptyMap; ops := emptyMap ]
  processDecl primNS (PType emptyFC "Int" Nothing)
  processDecl primNS (PType emptyFC "String" Nothing)
  processDecl primNS (PType emptyFC "Char" Nothing)
  setDef (QN primNS "PiType") emptyFC (Erased emptyFC) (PrimFn "(h0, h1) => ({ tag: \"PiType\", h0, h1 });" (S (S Z)) Nil) Nil
  top <- getTop
-  let mod = MkModCtx "" top.defs (MC emptyMap Nil 0 CheckAll) top.ops Nil top.errors Nil
-  let modules = updateMap primNS mod top.modules
-  -- TODO - do we clear this? Try just modules := modules, but wait until this refactor is done.
-  modifyTop [ modules := modules
-      ; imported := primNS :: Nil
-      ; hints := emptyMap
-      ; ns := ""
-      ; defs := emptyMap
-      ]
-  pure mod
+  modifyTop [ modules $= updateMap primNS top.currentMod ]
+  pure top.currentMod

 record FileSource where
  getFile : FC → String → M (String × String)
@@ -60,9 +53,11 @@ importHints (entry :: entries) = do
  when (elem Hint entry.eflags) $ \ _ => addHint entry.name
  importHints entries

-- HACK this is returning src to help render errors..
-- Maybe return module, put src and errors in module, add error for import with error, callers can sort out what they want to do?
-- The issue here is command line newt wants to report all errors (we can print that though?)  LSP wants something more subtle
+mergeOps : Operators → Operators → Operators
+mergeOps mod top = foldMap (flip const) top $ toList mod
+
+-- processModule might reset the currentModule in the topContext
+-- do not rely on topContext state afterwards - it may or may not contain the module
 processModule : FC → FileSource → List String → String → M ModContext
 processModule importFC repo stk modns = do
  top <- getTop
@@ -70,8 +65,8 @@ processModule importFC repo stk modns = do
  let (Nothing) = lookupMap' modns top.modules
    | Just mod => pure mod

-  let (False) = modns == primNS
-    | _ => addPrimitives
+  let (False) = modns == primNS | _ => addPrimitives
+
  let parts = split modns "."
  let fn = joinBy "/" parts ++ ".newt"
  -- TODO now we can pass in the module name...
@@ -92,47 +87,60 @@ processModule importFC repo stk modns = do
  imported <- for imports $ \case
    MkImport fc (nameFC, name') => do
      when (elem name' stk) $ \ _ => error nameFC "import loop \{modns} → \{name'}"
-      processModule nameFC repo (modns :: stk) name'
+      mod <- processModule nameFC repo (modns :: stk) name'
      pure $ name'
+
  processModule nameFC repo (modns :: stk) primNS
  let imported = snoc imported primNS

  putStrLn "module \{modName}"
+  top <- getTop
+  let freshMC = MC emptyMap Nil 0 CheckAll
+  let mod = MkModCtx modns src emptyMap freshMC emptyMap imported Nil Nil
+  modifyTop [ currentMod := mod
+            ; hints := emptyMap
+            ; ops := ops
+            ]

-  log 1 $ \ _ => "MODNS " ++ show modns
+  -- top hints / ops include all directly imported modules
+  for_ imports $ \case
+    (MkImport fc (nameFC, ns)) => do
+      let (Just mod) = lookupMap' ns top.modules | _ => error emptyFC "namespace \{show ns} missing"
+      importHints (listValues mod.modDefs)
+      modifyTop [ ops $= mergeOps mod.modOps ]
+
+      -- add error if an import contains an error
+      -- maybe move this to after reporting
+      case mod.modErrors of
+        Nil => pure MkUnit
+        _ => addError $ E nameFC "Error in import \{ns}"
+
+  log 1 $ \ _ => "parse Decls"
  top <- getTop
  (decls, ops) <- parseDecls fn top.ops toks Lin

-  top <- getTop
-  let freshMC = MC emptyMap Nil 0 CheckAll
-  -- NOW Print and drop errors here
-  -- clear per module fields before processing this module
-  modifyTop [ imported := imported
-            ; hints := emptyMap
-            ; ns := modns
-            ; defs := emptyMap
-            ; infos := Nil
-            ; metaCtx := freshMC
-            ; ops := ops
-            ]
-  for imported $ \ ns => do
-    let (Just mod) = lookupMap' ns top.modules | _ => error emptyFC "namespace \{show ns} missing"
-    importHints (listValues mod.modDefs)
+  -- TODO only include this module's ops
+  -- aside from reworking parsing, we could filter
+  -- other options are removing updates from parsing (so we must use incremental parsing)
+  -- or removing pratt from parsing (so it happens in elaboration)
+  modifyTop [ currentMod $= [ modOps := ops ] ]

  log 1 $ \ _ => "process Decls"
  traverse (tryProcessDecl src modns) (collectDecl decls)
+  top <- getTop

  -- This has addErrors as a side-effect
-  logMetas $ reverse $ listValues top.metaCtx.metas
+  logMetas $ reverse $ listValues top.currentMod.modMetaCtx.metas
+
+  -- print errors (for batch processing case)
+  for_ top.currentMod.modErrors $ \ err => putStrLn $ showError src err

  -- update modules with result, leave the rest of context in case this is top file
  top <- getTop
-  let mod = MkModCtx src top.defs top.metaCtx top.ops imported top.errors top.infos
-  let modules = updateMap modns mod top.modules
+  let modules = updateMap modns top.currentMod top.modules
  modifyTop [modules := modules]

-  -- FIXME module context should hold errors, to report in replay
-  pure mod
+  pure top.currentMod
  where
    tryProcessDecl : String → String → Decl → M Unit
    tryProcessDecl src ns decl = do
--- a/src/Lib/TopContext.newt
+++ b/src/Lib/TopContext.newt
@@ -7,32 +7,31 @@ import Prelude
 import Lib.Common
 import Lib.Types

-- I want unique ids, to be able to lookup, update, and a Ref so
-- I don't need good Context discipline. (I seem to have made mistakes already.)
-
+-- TODO move the def in here (along with M) or merge this into types
+-- The Monad can be its own file if we pull all of the monad update functions there.

 lookup : QName -> TopContext -> Maybe TopEntry
 lookup qn@(QN ns nm) top =
-  if ns == top.ns
-    then lookupMap' qn top.defs
+  if ns == top.currentMod.modName
+    then lookupMap' qn top.currentMod.modDefs
    else case lookupMap' ns top.modules of
      Just mod => lookupMap' qn mod.modDefs
      Nothing => Nothing

 lookupImported : String → TopContext -> List TopEntry
 lookupImported raw top =
-  mapMaybe (flip lookup top) $ (QN top.ns raw) :: map (flip QN raw) top.imported
+  mapMaybe (flip lookup top) $ (QN top.currentMod.modName raw) :: map (flip QN raw) top.currentMod.modDeps

 -- For repl / out of scope errors
 lookupAll : String → TopContext -> List TopEntry
 lookupAll raw top =
-  mapMaybe (flip lookup top) $ (QN top.ns raw) :: map (flip QN raw) (map fst $ toList top.modules)
+  mapMaybe (flip lookup top) $ (QN top.currentMod.modName raw) :: map (flip QN raw) (map fst $ toList top.modules)

 lookupRaw : String -> TopContext -> Maybe TopEntry
 lookupRaw raw top =
-  case lookupMap' (QN top.ns raw) top.defs of
+  case lookupMap' (QN top.currentMod.modName raw) top.currentMod.modDefs of
    Just entry => Just entry
-    Nothing => go top.imported
+    Nothing => go top.currentMod.modDeps
  where
    go : List String → Maybe TopEntry
    go Nil = Nothing
@@ -42,35 +41,33 @@ lookupRaw raw top =
        Just entry => Just entry
        Nothing => go nss

-
 instance Show TopContext where
-  show top = "\nContext:\n [\{ joinBy "\n" $ map (show ∘ snd) $ toList top.defs}]"
+  show top = "\nContext:\n [\{ joinBy "\n" $ map (show ∘ snd) $ toList top.currentMod.modDefs}]"

 emptyTop : TopContext
-emptyTop = MkTop emptyMap Nil emptyMap Nil "" emptyMap (MC emptyMap Nil 0 CheckAll) 0 Nil emptyMap
-
+emptyTop = MkTop emptyMap emptyMap (emptyModCtx "" "") 0 emptyMap

 setFlag : QName → FC → EFlag → M Unit
 setFlag name fc flag = do
  top <- getTop
-  let (Just (MkEntry fc nm ty def flags)) = lookupMap' name top.defs
+  let (Just (MkEntry fc nm ty def flags)) = lookupMap' name top.currentMod.modDefs
    | Nothing => error fc "\{show name} not declared"
-  modifyTop [ defs $= (updateMap name (MkEntry fc name ty def (flag :: flags))) ]
+  modifyTop [ currentMod $= [ modDefs $= (updateMap name (MkEntry fc name ty def (flag :: flags)))] ]

 setDef : QName -> FC -> Tm -> Def → List EFlag -> M Unit
 setDef name fc ty def flags = do
  top <- getTop
-  let (Nothing) = lookupMap' name top.defs
+  let (Nothing) = lookupMap' name top.currentMod.modDefs
    | Just (MkEntry fc' nm' ty' def' _) => error fc "\{show name} is already defined at \{show fc'}"
-  modifyTop $ \top =>
-    [ defs := (updateMap name (MkEntry fc name ty def flags) top.defs)] top
+
+  modifyTop [currentMod $= [ modDefs $= (updateMap name (MkEntry fc name ty def flags))] ]

 updateDef : QName -> FC -> Tm -> Def -> M Unit
 updateDef name fc ty def = do
  top <- getTop
-  let (Just (MkEntry fc' nm' ty' def' flags)) = lookupMap' name top.defs
+  let (Just (MkEntry fc' nm' ty' def' flags)) = lookupMap' name top.currentMod.modDefs
    | Nothing => error fc "\{show name} not declared"
-  putTop $ [ defs := updateMap name (MkEntry fc' name ty def flags) top.defs ] top
+  modifyTop [ currentMod $= [ modDefs := updateMap name (MkEntry fc' name ty def flags) top.currentMod.modDefs ] ]

 typeName : Tm → Maybe QName
 typeName (Pi fc nm Explicit rig t u) = Nothing
@@ -88,15 +85,11 @@ addHint qn = do
        | Nothing => error entry.fc "can't find tcon name for \{show qn}"
      let xs = fromMaybe Nil $ lookupMap' tyname top.hints
      let hints = updateMap tyname ((qn, entry.type) :: xs) top.hints
-      putTop $ [ hints := hints ] top
+      modifyTop [ hints := hints ]
    Nothing => pure MkUnit

 addError : Error -> M Unit
-addError err = do
-  top <- getTop
-  modifyTop [ errors $= (err ::) ]
+addError err = modifyTop [ currentMod $= [ modErrors $= (err ::) ] ]

 addInfo : EditorInfo → M Unit
-addInfo info = do
-  top <- getTop
-  modifyTop [ infos $= (info ::)]
+addInfo info = modifyTop [ currentMod $= [modInfos $= (info ::) ] ]
--- a/src/Lib/Types.newt
+++ b/src/Lib/Types.newt
@@ -398,12 +398,13 @@ data EditorInfo

 record ModContext where
  constructor MkModCtx
+  modName : String
  modSource : String
  modDefs : SortedMap QName TopEntry
  -- Do we need this if everything solved is zonked?
  modMetaCtx : MetaContext
  -- longer term maybe drop this, put the operator decls in ctxDefs and collect them on import
-  ctxOps : Operators
+  modOps : Operators
  modDeps : List String
  modErrors : List Error
  modInfos : List EditorInfo
@@ -416,8 +417,8 @@ record ModContext where
 -- expand these during normalization?

 -- A placeholder while walking through dependencies of a module
-emptyModCtx : String → ModContext
-emptyModCtx source = MkModCtx source emptyMap (MC emptyMap Nil 0 NoCheck) emptyMap Nil Nil Nil
+emptyModCtx : String → String → ModContext
+emptyModCtx modName source = MkModCtx modName source emptyMap (MC emptyMap Nil 0 NoCheck) emptyMap Nil Nil Nil

 HintTable : U
 HintTable = SortedMap QName (List (QName × Tm))
@@ -428,23 +429,17 @@ instance HasFC EditorInfo where
  getFC (CaseSplit fc _ _ _) = fc
  getFC (MissingCases fc _ _) = fc

-
+-- modules are "modules"
+-- currentMod represents the current module
+-- when we switch modules, load imports into ops and hints
+-- as we process the decls, update ops and currentMod.ops
 record TopContext where
  constructor MkTop
  modules : SortedMap String ModContext
-  imported : List String
-  -- TCon name → function name × type
  hints : HintTable
-  infos : List EditorInfo
-
  -- current module
-  ns : String
-  defs : SortedMap QName TopEntry
-  metaCtx : MetaContext
-
-  -- Global values
-  verbose : Int -- command line flag
-  errors : List Error
+  currentMod : ModContext
+  verbose : Int -- command line flag increments this
  ops : Operators

 -- we'll use this for typechecking, but need to keep a TopContext around too.
@@ -592,7 +587,7 @@ error' msg = throwError $ E emptyFC msg
 lookupMeta : QName -> M MetaEntry
 lookupMeta ix@(QN ns nm) = do
  top <- getTop
-  case lookupMap' ix top.metaCtx.metas of
+  case lookupMap' ix top.currentMod.modMetaCtx.metas of
    Just meta => pure meta
    Nothing => case lookupMap' ns top.modules of
      Nothing =>
--- a/src/Main.newt
+++ b/src/Main.newt
@@ -65,11 +65,8 @@ baseDir Lin _ = Left "module path doesn't match directory"
 showErrors : String -> String -> M Unit
 showErrors fn src = do
  top <- getTop
-  -- TODO {M} needed to sort out scrutinee
-  let (Nil) = top.errors
-    | errors => do
-        traverse (putStrLn ∘ showError src) errors
-        throwError $ E (MkFC fn $ MkBounds 0 0 0 0) "Compile failed"
+  let (Nil) = top.currentMod.modErrors
+    | _ => throwError $ E (MkFC fn $ MkBounds 0 0 0 0) "Compile failed"
  pure MkUnit