If I do:
val l = Seq(("un", ""), ("deux", "hehe"), ("trois", "lol"))
l map { t => t._1 + t._2 }
It's ok.
If I do:
val l = Seq(("un", ""), ("deux", "hehe"), ("trois", "lol"))
l map { case (b, n) => b + n }
It's ok too.
But if I do:
val l = Seq(("un", ""), ("deux", "hehe"), ("trois", "lol"))
l map { (b, n) => b + n }
It will not work.
Why should I use "case" keyword to use named tuples?
The error message with 2.11 is more explanatory:
scala> l map { (b, n) => b + n }
<console>:9: error: missing parameter type
Note: The expected type requires a one-argument function accepting a 2-Tuple.
Consider a pattern matching anonymous function, `{ case (b, n) => ... }`
l map { (b, n) => b + n }
^
<console>:9: error: missing parameter type
l map { (b, n) => b + n }
^
For an apply, you get "auto-tupling":
scala> def f(p: (Int, Int)) = p._1 + p._2
f: (p: (Int, Int))Int
scala> f(1,2)
res0: Int = 3
where you supplied two args instead of one.
But you don't get auto-untupling.
People have always wanted it to work that way.