This is a shorthand for writing anonymous functions. The &() activates the feature for the expression inside, which can then use &1, &2 etc to apply parameters.

This is a shorthand for writing anonymous functions. The &() activates the feature for the expression inside, which can then use &1, &2 etc to apply parameters. For example `&(&1 + 1)` is equivalent to `fn x -> x + 1 end` .