On Tue, Jul 31, 2001 at 10:51:35AM +1200, Greg Ewing wrote:
> Skip Montanaro <skip@pobox.com>:
> > The main stumbling block was that pesky "from module import *"
> > statement. It could push an unknown quantity of stuff onto the
> > stack
> Are you *sure* about that? I'm pretty certain it can't
> be true, since the compiler has to know at all times
> how much is on the stack, so it can decide how much
> stack space is needed.
I think Skip meant it does an arbitrary number of
load-onto-stack
store-into-namespace
operations. Skip, you'll be glad to know that's no longer true :) Since 2.0
(or when was it that we introduced 'import as' ?) import-* is not a special
case of 'IMPORT_FROM', but rather a separate opcode that doesn't touch the
stack. 'IMPORT_FROM' is now only used to push a given name from TOS onto the
stack:
>>> def eggs():
... from stat import a, b
>>> dis.dis(eggs)
...
9 IMPORT_NAME 0 (stat)
12 IMPORT_FROM 1 (a)
15 STORE_FAST 1 (a)
18 IMPORT_FROM 2 (b)
21 STORE_FAST 0 (b)
24 POP_TOP
...
>>> def spam():
... from stat import *
>>> dis.dis(spam)
...
6 LOAD_CONST 1 (('*',))
9 IMPORT_NAME 0 (stat)
12 IMPORT_STAR
...
Bloody hell, what's that LOAD_CONST doing there ? I think I found a bug ;P
Sigh... Sleep first, fix later.
--
Thomas Wouters <thomas@xs4all.net>
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