Currying in ruby 1.8

curry.rb

class Proc
  def curry(*args)
    if args.size < self.arity
      args_string = ('a'..'z').take(self.arity-args.size).join(',')
      given_args  = []
      args.size.times {|i| given_args << "args[#{i}]"}
      given_args  = given_args.join(", ")
      eval "lambda {|#{args_string}| self.call(#{given_args}, #{args_string})}"
    elsif args.size > self.arity
      raise ArgumentError, "Wrong # of arguments to curried function(#{args.size} for #{self.arity.size})"
    else
      self.call(*args)
    end
  end
  alias_method :apply, :curry
end

gistfile1.rb

plus = lambda {|x,y| x + y }
plus1 = plus.apply(1)
minus1 = plus.apply(-1)

plus1.apply(2) #=> 3
minus1.apply(2) #=> 1