procs.rb

require 'benchmark'

def resolve(obj)
  obj.respond_to?(:call) ? resolve(obj.call) : obj
end

def resolve2(obj)
  if obj.respond_to?(:call)
    resolve2(obj.call)
  else
    obj
  end
end

def resolve3(obj)
  while obj.respond_to?(:call)
    obj = obj.call
  end
  obj
end

open  = 1500.times.map { "proc {" }.join(" ")
close = 1500.times.map { "}" }.join(" ")
f     = eval(open + "Time.now" + close)

Benchmark::bm do |x|
  x.report { resolve(f) }
  x.report { resolve2(f) }
  x.report { resolve3(f) }
end