Sequenceを作る関数をPythonとRubyで書いてみた

gistfile1.txt

##
## Python
##
def seq(initial, formula):
    x = initial
    while True:
        yield x
        x = formula(x)

sequence = seq(1, lambda x: x+1)
print(next(sequence))  #=> 1
print(next(sequence))  #=> 2
print(next(sequence))  #=> 3

##
## Ruby
##
def seq(initial, &formula)
  x = initial
  Enumerator.new do |yielder|
    loop {
      yielder << x
      x = yield x
    }
  end
end

sequence = seq(1) {|x| x+1 }
puts sequence.next   #=> 1
puts sequence.next   #=> 2
puts sequence.next   #=> 3