parrot: scry api about aviary

[rabsef-bicrym]

::  +peek: handles on-peek
::
++  peek
  |=  pol=(pole knot)
  ^-  (unit (unit cage))
  ?+    pol  !!
    [%blok ~]  ``parrot-state-blok+!>(`_blok`blok)      ::  get blocked hosts
    [%pend ~]  ``parrot-state-pend+!>(`_pend`pend)      ::  get pending invites
    [%sent ~]  ``parrot-state-sent+!>(`_sent`sent)      ::  get sent invitations
    [%flok ~]  ``parrot-state-flok+!>(`_flok`flok)      ::  get current flocks
  ::
      [%aval ~]                                         ::  get available hosts
    =;  used=(set flag)
      ``parrot-state-aval+!>(`(set flag)`(~(dif in chats:scry) used))
    %-  ~(rep by flok)
    |=  [[@ h=flag t=(set flag)] o=(set flag)]
    ?:  =(our.bol p.h)  (~(put in o) h)
    ?~(h=(~(get by t) our.bol) o (~(put in o) our.bol u.h))
  ==