From: "S.Volkov" <svolkov@...>
Date: 2007-02-09T18:20:08+09:00
Subject: Re: Your favorite bit of ruby code?

"Carl Lerche" <carl.lerche@gmail.com> wrote in message 
news:ab90312e0702081249ib5fcd61y924299d020f48526@mail.gmail.com...
>
> I'd like to see some of them!

my 2c:

###
Fibonacci = Hash.new{ |ht, k| ht[k] = k<2 ? 1 : ht[k-1] + ht[k-2] }
# Sample
p Fibonacci[100]
#-> 573147844013817084101

###
class String
    # define new String method for 'array' springs replacement
    def gsubs_a originals, replacements
        # create replacements table
        orig2repl = Hash[ *originals.zip( replacements ).flatten ]
        # regexp matching any original
        regexp = /#{originals.map{ |s| Regexp.escape s }.join( '|' )}/
        # substitute each original with replacement from table
        self.gsub( regexp ){ |orig| orig2repl[ orig ] }
    end
end
# Sample
puts "AB[^1-2$].XY".gsubs_a( ["AB", "1-2", "XY", "."], ["CC", "99", "ZZ", 
"+"] )
#-> CC[^99$]+ZZ

enjoy!
Sergey