static keyword

[Michael Walter]

Peter Hansen wrote:
> Nick Jacobson wrote:
> 
>> I believe the following "static" command would be useful in Python.
> 
> [snip]
> 
>> Just like in C, the variables i and firstcall are only assigned the
>> first time foo() is called.  To get this effect currently, one could
>> use default arguments or wrapping the whole thing in a class.  Both of
>> these solutions seem like hacks, the above method IMO is more
>> Pythonic. :)
> 
> 
> I'm not sure how to interpret the smiley, but I'll take it
> you weren't actually joking...
> 
> Why do you call using OO ("wrapping it in a class", as you say)
> a "hack"?  Generally speaking, using objects to contain state
> information such as this is exactly what most people would call
> the cleanest, best approach.
 > [...]
There's also a bunch of people who would consider this (modulo my 
obvious mistakes ;) the cleanest, best approach:

(let ((first-call #t)
       (i '(10 11)))
   (define (foo)
     (when (first-call)
           (begin (display "first pass") (set! first-call #f))
     (set! (array-ref i 0) (+ (array-ref i 0) 1))
     (display (array-ref i 0))))

I.e. capture the state in a normal lexical variable.

Cheers,
Michael