keys_to_ints.rb

bighash = {}.tap do |h|
  (1..40_000).each do |i|
    h[i.to_s] = i
  end
end


smallhash = { "1" => 2, "5" => 6,  "3" => 4 }


def keys_to_ints1 h
  {}.tap do |x|
    h.each do |k,v|
      x[k.to_i] = v
    end
  end
end

def keys_to_ints2 h
  k = h.keys.map(&:to_i)
  Hash[k.zip(h.values)]
end



raise "f" if not  keys_to_ints1(smallhash) == keys_to_ints2(smallhash)


require 'benchmark'

Benchmark.bmbm do |x|
  x.report("keys_to_ints1") { keys_to_ints1(bighash) }
  x.report("keys_to_ints2") { keys_to_ints2(bighash) }
end


=begin
Rehearsal -------------------------------------------------
keys_to_ints1   0.030000   0.010000   0.040000 (  0.027994)
keys_to_ints2   0.010000   0.000000   0.010000 (  0.019940)
---------------------------------------- total: 0.050000sec

                    user     system      total        real
keys_to_ints1   0.030000   0.000000   0.030000 (  0.033963)
keys_to_ints2   0.020000   0.000000   0.020000 (  0.020238)
=end