how to write function that returns function

[Paul Graham]

Thanks to several people who have sent me Python
"translations" for the following:

Scheme:  (define (foo x) 
           (lambda (y) (set! x (+ x y))))

Perl:    sub foo {
           my ($n) = @_;
           sub {$n += shift}
         }

Here is a summary of the answers I got.  This is
the closest thing to a direct translation:

def foo(n):
  s = [n]
  def bar(i):
    s[0] += i
    return s[0]
  return bar

but it is considered ugly, and the canonical way to
do this seems to be by defining a class:

class foo:
  def __init__(self, n):
      self.n = n

  def __call__(self, i):
      self.n += i
      return self.n


--pg