From: Robert Klemme <shortcutter@...>
Date: 2007-10-26T17:17:08+09:00
Subject: Re: Skip the first invocation e.g. skip_first { foo }

2007/10/26, Brian Adkins <lojicdotcom@gmail.com>:
> On Oct 25, 6:50 pm, Gary Wright <gwtm...@mac.com> wrote:
> > On Oct 25, 2007, at 6:40 PM, Brian Adkins wrote:
> >
> > > Consider the following code:
> >
> > > first = true
> > > 3.times do
> > >   if first
> > >     first = false
> > >   else
> > >     puts 'foo'
> > >   end
> > >   ...
> > > end
> >
> > 3.times do |i|
> >    print '2nd or more: ' unless i.zero?
> >    puts "iteration: #{i}"
> > end
>
> I guess I wasn't clear enough. This should work in any type of
> iteration, so a loop index may not be available. For example:
>
> foo.each do |bar|
>   skip_first { ... }
>   ...
> end

Of course there is also a solution with #inject. It can be abused when
using this form:

foo.inject do |junk,x|
  puts x
end

:-)

Other than that you could do

module Enumerable
  def skip(n,&b)
    raise ArgumentError, "invalid skip count" if n<0
    each_with_index {|a,i| b[a] if i>=n}
  end
end

This could be extended to skip the last n elements if n is negative
but this is more complex.

Kind regards

robert