What does the arrow in an import statement do?

2018-06-26 00:58:14

I've found the the following import in some scala :

import Predef.{println => _, _}

What does the => do?

Generally => in an import allows you to alias an existing name into an alternate name:

import scala.{Int => i32}

This would allow you to use i32 in place of Int

Further, importing _ imports all symbols into the current namespaces.

Now, aliasing a name into _ , however does the opposite, ie excludes it from the import:

import Predef.{println => _, _}

means

*Import all from Predef except println

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