Getting the current value of a "Ugen" and send to js?

[hems]

a = SinOsc.kr( 440 )

Message.send "a:value", a.get() # <~ how do i get the "current value" of "a" ?

Will i need to "play" it, to get it going?

( -> 
  $a = SinOsc.ar( 55 ) 
).play()

console.log($a)

Message.send "a:value", $a.get() # <~ how do i get the "current value" of "$a" ?

[hems]

is there a way of pulling this one?

Is there some class with a functionality close to Bus "getSynchronous" method?
http://doc.sccode.org/Classes/Bus.html

There's also "poll" but i think this one works with audio rate and might be too expensive just for pulling values: http://doc.sccode.org/Classes/Poll.html