Improved declareField

src/syndicate/dataspaces.nim

@@ -68,7 +68,9 @@ type
     updateProc: Script[EndpointSpec]
     spec: EndpointSpec
 
-  Fields = seq[Preserve]
+  Field* = object of RootObj
+    id*: FieldId
+  Fields* = seq[Preserve]
     # TODO: compile-time tuples
 
   Turn = object
@@ -301,7 +303,7 @@ proc terminate(facet) =
       actor = facet.actor
       parent = facet.parent
     if parent.isSome:
-      parent.get.children.del(facet.id)
+      get(parent).children.del(facet.id)
     else:
       reset actor.rootFacet
     facet.isLive = false
@@ -552,88 +554,23 @@ proc bootModule*(bootProc: ActivationScript): Future[void] =
     true
   return g.future
 
-template declareField*(facet: Facet; F: untyped; T: typedesc; init: T): untyped =
-  ## Declare getter and setter procs for field `F` of type `T` initalized with `init`.
-  # TODO: do more at compile-time, use a tuple rather than a sequence of Preserves.
-  facet.fields.add(toPreserve(init))
-  let
-    `F FieldOff` = facet.fields.high
-    `F FieldId` = facet.actor.dataspace.generateId.FieldId
-  facet.actor.dataspace.dataflow.defineObservableProperty(`F FieldId`)
-
-  proc `F`(fields: Fields): T =
-    facet.actor.dataspace.dataflow.recordObservation(`F FieldId`)
-    fromPreserve[T](result, facet.fields[`F FieldOff`])
-
-  proc `F =`(fields: var Fields; x: T) =
-    facet.actor.dataspace.dataflow.recordDamage(`F FieldId`)
-    facet.fields[`F FieldOff`] = toPreserve[T](x)
-
-  proc `F =`(fields: var Fields; x: Preserve) =
-    assert(x.kind == facet.fields[`F FieldOff`].kind, "invalid Preserves item for field type")
-    facet.actor.dataspace.dataflow.recordDamage(`F FieldId`)
-    facet.fields[`F FieldOff`] = x
-
-
-#[
-# Some early macros
-
-proc send() =
-  discard
-
-proc generateField(stmt: NimNode): NimNode =
-  stmt.expectLen 3
-  let l = stmt[1]
-  let r = stmt[2]
-  case r.kind
-  of nnkStmtList:
-    r.expectLen 1
-    result = newNimNode(nnkVarSection).add(newIdentDefs(l, r[0]))
-  else:
-    raiseAssert("unhandled field " & r.treeRepr)
-
-proc generateStopOnTuple(output: var NimNode; stmt: NimNode): NimNode =
-  stmt.expectLen 3
-  let
-    cond = stmt[1]
-    body = stmt[2]
-    # symCond = genSym(ident="stopOnCond")
-    symStop = genSym(ident="stopOnCb")
-  # output.add(newProc(name = symCond, params = [ident"bool"], body = cond))
-  output.add(newProc(name = symStop, body = body))
-  newPar(newColonExpr(ident"cond", cond), newColonExpr(ident"body", symStop))
-
-macro spawn*(label: string; body: untyped) =
-  ## Spawn actor.
-  result = newNimNode(nnkStmtList)
-  let blockBody = newNimNode(nnkStmtList)
-  let actorSym = genSym(nskVar, label.strVal)
-  result.add(newNimNode(nnkVarSection).add(
-    newIdentDefs(actorSym, ident"Actor")))
-  var stopOnSeq = newNimNode(nnkBracket)
-  body.expectKind nnkStmtList
-  for stmt in body:
-    case stmt.kind
-    of nnkCommentStmt:
-      result.add(stmt)
-    of nnkCommand:
-      let cmd = stmt[0]
-      cmd.expectKind nnkIdent
-      if eqIdent(cmd, "field"):
-        result.add(generateField(stmt))
-      elif eqIdent(cmd, "stopOn"):
-        let stop = generateStopOnTuple(result, stmt)
-        stopOnSeq.add(stop)
-      else:
-        raiseAssert("unhandled spawn command " & cmd.repr)
-    else:
-      raiseAssert("unhandled statment " & stmt.treeRepr)
-  result.add(
-    newAssignment(newDotExpr(actorSym, ident"stops"), prefix(stopOnSeq, "@")))
-  #result.add(newBlockStmt(blockBody))
-  echo result.repr
-  # echo result.treeRepr
-
-macro dumpStuff*(body: untyped): untyped =
-  echo body.treeRepr
-]#
+template declareField*(facet: Facet; F: untyped; T: typedesc; initial: T): untyped =
+  ## Declare getter and setter procs for field `F` of type `T` initalized with `initial`.
+  type DistinctField = object of Field
+    discard
+  let `F` {.inject.} = DistinctField(id: facet.actor.dataspace.generateId.FieldId)
+  facet.actor.dataspace.dataflow.defineObservableProperty(`F`.id)
+  facet.fields.add(toPreserve(initial))
+  let fieldOff = facet.fields.high
+  proc set(f: DistinctField; x: T) =
+    facet.actor.dataspace.dataflow.recordDamage(f.id)
+    facet.fields[fieldOff] = toPreserve[T](x)
+  proc set(f: DistinctField; x: Preserve) =
+    facet.actor.dataspace.dataflow.recordDamage(f.id)
+    facet.fields[fieldOff] = x
+  proc get(f: DistinctField): T =
+    facet.actor.dataspace.dataflow.recordObservation(f.id)
+    fromPreserve[T](result, facet.fields[fieldOff])
+  proc getPreserve(f: DistinctField): Preserve =
+    facet.actor.dataspace.dataflow.recordObservation(f.id)
+    facet.fields[fieldOff]