Function literal with call-by-name parameter

Question

How does one define an anonymous function with call-by-name parameters in scala?

I tried the following:

val fun = (x: Boolean, y: =>Int) => if(x) y else 0

This works well with call-by-value y, but not with call-by-name. Why?

Answer 1

它可以完成，但方式略有不同：与参数分开声明类型：

val fun: (Boolean, => Int) => Int = (x, y) => if (x) y else 0