Scala: Parallel assignment of Tuples

Question

Is it possible to assign tuple members in parallel in Scala. if not is there another technique to accomplish something similar?

val players = List(
    new Player("Django Reinhardt", 42), 
    new Player("Sol Hoopii", 57),
    new Player("Marc Ribot", 64)
)

val winners, losers = players.partition(p => p.score > 50)

// winners = List(Player name:Sol Hoopii score: 57, Player name:Marc Ribot score: 64)
// losers = List(Player name:Django Reinhardt score: 42)

if you didnt know you can use the short hand notation: players.partition(_.score > 50) — Schildmeijer, Feb 05 '10 at 16:52

score 20 · Accepted Answer · answered Feb 05 '10 at 13:43

20

val winners, losers = players.partition(p => p.score > 50)

Assignes the (List, List) tuple to two variables. If you want to unpack the tuple you have to use

val (winners, losers) = players.partition(p => p.score > 50)

Which does exactly what you want. :-)

answered Feb 05 '10 at 13:43

Malax

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+1 for pointing out what the syntax without parenthesis means. Or, rather, if I _could_ award one additional vote, I would. :-) – Daniel C. Sobral Feb 05 '10 at 15:58
I suggest, though, that you also point out the tuple assignment works because it is actually a pattern matching. – Daniel C. Sobral Feb 05 '10 at 16:00
I would be certainly be interested in the pattern matching example – BefittingTheorem Feb 05 '10 at 16:57

Scala: Parallel assignment of Tuples

1 Answers1