 
   toProperty: (initValue) ->
     initValue = None if arguments.length == 0
-    @scan(initValue, latter)
+    @scan(initValue, latterF, true)
 
   toEventStream: -> this
 

      left[key](right)
  else
    assert "not a function or a field key: " + f, false
toOption = (v) ->
  if v instanceof Some || v == None
    v

      if event.isEnd()
        ended = true
      if event.hasValue()
        current = new Some(event.value)
        #console.log "push", event.value()
      PropertyTransaction.inTransaction =>
        push.apply(this, [event])
