有没有一种惯用的方式来转换一个函数?
val x: A => (B, C) = ...
to
val y: A => (C, B) = ...
有没有一种惯用的方式来转换一个函数?
val x: A => (B, C) = ...
to
val y: A => (C, B) = ...
Tuple2.swap
可以将(B, C)
更改为(C, B)
。A => (B, C)
转换为A => (C, B)
可以使用.andThen(_.swap)
实现。例如:
scala> val a = (i: Int) => (s"$i", i.toDouble)
a: Int => (String, Double) = <function1>
scala> val b = a.andThen(_.swap)
b: Int => (Double, String) = <function1>
scala> b(5)
res1: (Double, String) = (5.0,5)