Created
October 10, 2013 21:39
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def yipWhenL[I,O,O2](ord: (I,O) => Ordering)(f: (I,Option[O]) => O2): Wye[I,O,O2] = { | |
val fbL = tee.passL[I] map (f(_,None : Option[O])) | |
def go(io : Option[I], oo : Option[O]): Wye[I,O,O2] = { | |
io match { | |
case None => awaitL[I].flatMap { i => go(Some(i), oo) } | |
case Some(i) => oo match { | |
case None => awaitR[O].flatMap(o => go(io,Some(o))) // TODO receiveROr(fbL)... | |
case Some(o) => ord(i,o) match { | |
case Ordering.LT => emit(f(i,None)) then go(None,oo) | |
case Ordering.EQ => emit(f(i,oo)) then go(None,None) | |
case Ordering.GT => go(io,None) | |
} | |
} | |
} | |
} | |
go(None,None) | |
} |
I think the ord
function is fine. You definitely want to allow the two types to be different, since you might be using this to join like a (A,B,C)
with a B
, using only the B
for comparison.
Thanks, for showing me how to get to the fallback state. Also what is the meaning of the fby name?
OK, I'll work with those names and we can discuss it once again when I send the PR.
fby
is short for 'followedBy'. It's a semi-standard name in stream processing / dataflow programming. :)
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You should be able to do:
awaitR[0].flatMap(o => go(io,Some(o))).orElse(fbL)
. Alsothen
is nowfby
.For the name, I'm not sure. You are basically resampling the right input to match the left, but using an ordering to find the alignment. Maybe
orderedAlignL
oralignOrderedL
? 'Align' usually means some sort of zipping, but allowing for differences in shape. And it is left-biased, and based on some ordering rather than based on position.