From: Joel VanderWerf <vjoel@...>
Date: 2003-01-14T13:16:03+09:00
Subject: Re: RCR: String#indent(n)

Gavin Sinclair wrote:
> Rubyists,
> 
> I think a fine companion for String#ljust, String#rjust and
> String#center would be String#indent.

It's pretty easy to just use gsub instead:

   text.gsub(/^/, " "*4)

whereas ljust, rjust, and center would require a little more work to 
emulate with gsub. Or do you have more functionality in mind?

Just for the heck of it, here are some bits I use from time to time. 
They might fit in some kind of string formatting library.

class String

   # tabs left or right by n chars, using spaces
   def tab n
     if n >= 0
       gsub(/^/, ' ' * n)
     else
       gsub(/^ {0,#{-n}}/, "")
     end
   end

   # preserves relative tabbing
   # the first non-empty line ends up with n spaces before nonspace
   def tabto n
     if self =~ /^( *)\S/
       tab(n - $1.length)
     else
       self
     end
   end

   # aligns each line
   def taballto n
     gsub(/^ */, ' ' * n)
   end

end