Question

I can name objects like this, but can’t call m:

object + {
  def m (s: String) = println(s)
}

Can’t call +.m("hi"):

<console>:1: error: illegal start of simple expression
       +.m("hi")

Also can’t call + m "hi" (preferred for DSL-usage).

But with object ++ it works fine! Do they conflict with (not existent) unary_+ methods? Is it possible to avoid this?

Answer 1

Indeed it is not possible with unary operators. If you want to call it anyways, you could resort to using the name generated by the compiler for the JVM (which starts with a dollar):

scala> object + {
     | def m( s: String ) = println(s)
     | }
defined module $plus

scala> +.m("hello")
<console>:1: error: illegal start of simple expression
       +.m("hello")
        ^

scala> $plus.m("hello")
hello