Re: Using _ like in Scala?

On Tue, Feb 7, 2012 at 4:47 AM, Robert Klemme <[e-mail]>wrote:

> On Tue, Feb 7, 2012 at 6:56 AM, Kevin <[e-mail]> wrote:
> > It would make more sense to just eliminate the need to type even a
> > place holder while keeping the current form.  I.E. fruits.each{puts}
> > Or come up with semantics that allow the interpreter to accept an
> > input like "puts fruits" and have Ruby unwind the collection.
>
> Like
>
> irb(main):001:0> class Object
> irb(main):002:1> def out(io = $stdout) io.puts(self) end
> irb(main):003:1> end
> => nil
> irb(main):004:0> fruits = %w( apple banana orange )
> => ["apple", "banana", "orange"]
> irb(main):005:0> fruits.each &:out
> apple
> banana
> orange
> => ["apple", "banana", "orange"]
>
> ?  Btw, I don't like _ either.
>
>
I do this sometimes, but I do it like this

%w[apple banana orange].each &method(:puts)
# >> apple
# >> banana
# >> orange

This one isn't too bad. It can get kind of gross when you need to get the
method from elsewhere, though:

%w[apple banana orange].each &Kernel.method(:puts)
# >> apple
# >> banana
# >> orange


I wouldn't mind if there were cleaner ways of accessing the methods
themselves (some kind of syntax).



Although what I'd really like would be a syntax for naming inline blocks,
then my editor could fold the block body inside the name, something like
%w[apple banana orange].each display

And it would expand to something like
%w[apple banana orange].each { |display -> fruit| puts fruit }

Then it looks good if it's in plain text or managed by the editor. The
biggest benefit to me is that it allows you to abstract the implementation
of what you want to do with this thing from its implementation, but without
littering your class with methods only used in one place (also methods
aren't closures, so often won't work for this.

I've played around with this idea using methods
def display
  lambda { |fruit| puts fruit }
end
%w[apple banana orange].each &display

and using local variables
display = lambda { |fruit| puts fruit }
%w[apple banana orange].each &display


But never found anything I was very happy with.