2009/4/15 Srijayanth Sridhar <srijayanth / gmail.com>:
> Hello,
>
> I am using OptionParser and one of the nifty things it has is multi line
> descriptions for each option. I have a particularly long list of valid
> arguments for a valid option, for instance cities=[London,Paris,NY......].
> If printed in a single line it runs over and looks ugly. My hack so far is:
>
> def pretty_print_list list,num=5
> a=[]
> (0...list.size).step(num) { |i| a << (list[i...i+num]).join(',') }
> a
> end
>
> This returns a list of strings which I pass as *list to the OptionParser .on
> method as follows:
>
> arg.on("--city [CITY]",cities,*list) { |o| options.city=o }
>
> The hack works fine, but on a broader subject, is there a nice easy way of
> grouping arrays? In python Range accepts a step value which is quite
> awesome...

#each_slice does the job:

irb(main):008:0> a = (1..10).to_a
=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
irb(main):009:0> a.each_slice(3).to_a
=> [[1, 2, 3], [4, 5, 6], [7, 8, 9], [10]]

Cheers

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/