Michal Wallace <[EMAIL PROTECTED]> writes:
> Okay, I definitely need some help understanding this.
Okay, I definitely did a suboptimal job trying to
clarify...
> Here's some python code that defines a closure:
>
> def make_adder(base):
> def adder(x):
> return base+x
> return adder
> h = make_adder(10)
> print h(5)
>
> When I run this in python 2.2, it prints "15".
>
> When I run it through pirate, I get this:
>
> -scratch_pad: too deep
>
> Now, in my mind:
>
> depth 0 has: make_adder, h
> depth 1 has: base, adder
> depth 2 has: x
This sounds right.
> The top level .sub should start with 'new_pad 0'
> The make_adder .pcc_sub should start with 'new_pad 1'
> The adder .pcc_sub should start with 'new_pad 2'
Right.
> I think the error happens because I'm calling a depth 2
> function from depth 0, but if I change adder's new_pad
> depth to 1, it can't find "base".
>
> I don't know how to get this to work the way I want.
> Can anyone help me out here?
> ...
> # make_adder from line 2
> .pcc_sub _sub0 non_prototyped
> .param object base
> new_pad 1
> store_lex -1, 'base', base
> setline 3
> newsub $P1, .Sub, _sub1
The problem is that when adder() gets returned, it
needs to remember the enclosing pad. So this needs to
be
newsub $P1, .Closure, _sub1
which (IIRC) will save the lexical environment in which
it was created (see closure.pmc), then restore that
when it is invoked.
/s
