merits of Lisp vs Python

[Alex Mizrahi]

(message (Hello 'Paul)
(you :wrote  :on '(10 Dec 2006 00:01:34 -0800))
(

 PR> I'm not persuaded, I haven't examined his example carefully yet but it
 PR> looks like basically a reader hack.  Lexical scope in Lisp means among
 PR> other things lexical closures and (maybe I'm mistaken) it seemed to me
 PR> Alex's example didn't supply that.

lexical scope is pretty low-level concept that affects lot of stuff, so it 
requires lot of changes -- we are not extending a language, but build a new 
one actually.
we'll have to create object 'lexical environment' and to query it for 
variable values instead of just using variable values: var -> (query env 
'var).
then, we'll need to make closures -- that is a pair of environment and code 
itself.
so, it's very close to writting new interpreter -- but it's order of 
magnitude easier to write this interpreter via macros than from scratch, 
most other language constructs can be reused.
that's the point -- macros allow to implement a language with aprox. same 
syntax but different semantics relatively easily.

 PR>   I'm also unconvinced (so far) of his description of call/cc as a Lisp
 PR> macro but that's going to take me some head scratching.

there is a chapter about continuations in Paul Graham's "On Lisp".

"Common Lisp doesn't provide call/cc, but with a little extra effort we can 
do the same things as we can in Scheme. This section shows how to use macros 
to build continuations in Common Lisp programs."

)
(With-best-regards '(Alex Mizrahi) :aka 'killer_storm)
"People who lust for the Feel of keys on their fingertips (c) Inity")