clicklog

メモ

Ruby

def f
        i = 0
        return lambda {
                i += 1
        }
end

x = f
puts x.call()
puts x.call()
puts x.call()

Python 2.x

def f():
        i = [0]
        def g():
                i[0] += 1
                return i[0]
        return g
x = f()
print x()
print x()
print x()

Python 3.x

def f():
        i = 0
        def g():
                nonlocal i
                i += 1
                return i
        return g

x = f()
print(x())
print(x())
print(x())

ちなみに、ジェネレータのおまけ

def f():
        i = 0
        while True:
                i += 1
                yield i

g = f()
print g.next()
print g.next()
print g.next()