I can define a bang operator method, but I cannot name it in Scala. What for?

Question

First, I define a method !

:

scala> def !() = "hi"
$bang: ()java.lang.String

Now I can call it like this:

scala> $bang()
res3: java.lang.String = hi

But this doesn't work:

scala> !()
<console>:8: error: value unary_! is not a member of Unit
              !()

Even this doesn't work:

scala> `!`()
<console>:8: error: value unary_! is not a member of Unit
              `!`()
              ^

What am I doing wrong here? Why can I detect !()

when I cannot call it?

EDIT1

Adding an object reference gives an error:

scala> this.!()
<console>:8: error: value ! is not a member of object $iw
              this.!()
                   ^

+3

tuxdna 13 oct. 14 at 10:56

1 answer

Jörg W Mittag · Answer 1 · 2014-10-13T12:11:31+0000

!foo

interpreted as

foo.unary_!

If you want to call your method, you must provide an explicit receiver, eg.

this.!()

or

this !()

or

this ! ()