Anonymous

module ToSLookup
    CACHE = {}
    def self.get number, *args
        CACHE[[number, args]] or (CACHE[[number, args]] = number.convert_to_string *args)
    end
end

[Bignum, Fixnum, Float].each do |klass|
    klass.class_eval do
        alias :convert_to_string :to_s
        def to_s *args
            ToSLookup.get self, *args
        end
    end
end

require 'benchmark'

Benchmark.bm do |x|
    x.report('old way:') { 1000.times { -1000.upto(1000) { |i| i.convert_to_string } } }
    x.report('new way:') { 1000.times { -1000.upto(1000) { |i| i.to_s } } }
end