nested scopes

[Michael Hudson]

Darren New <dnew at san.rr.com> writes:

> D-Man wrote:
> > Do you know of any situations where it would be advantageous to have
> > dynamic scoping instead of static scoping?  (Note that I'm not asking
> > for situations where dynamic scoping exists, but where it would be
> > better)
> 
> My understanding is that it was more an artifact of the implementation of
> LISP than it was a desirous effect. It might be better if you're trying to
> form closures or do funky macro stuff or something, but I'm not sure.

It's good when you're calling a function (call it A) that calls
another function (call this one B) that has parameterizable behaviour,
because A doesn't have to put all of B's parameters in its argument
list - you get B to read these paramters from special (ie. dynamically
scoped) variables and bind them around your call to A.  Can't think of
a real good example now, I'm afraid.  The Common Lisp printer uses
special variables extensively.

I'm not sure this could be made to work in Python, not least because
it has a rather different notion of binding to Python.

Cheers,
M.

-- 
  Roll on a game of competetive offence-taking. 
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