merits of Lisp vs Python

[Bill Atkins]

greg <greg at cosc.canterbury.ac.nz> writes:

>> A compiler shifts a lot of decisions that an
>> interpreter would have to make at runtime to compile-time.  There is
>> no reason a dynamic language can't enjoy this efficiency.
>
> I'm not saying that it's impossible to compile
> Python, only that's there's a lot more to it than
> just macro expansion. The OP was saying something
> like "If you added macros, you might get a compiler
> for free", which is clearly far from true.

Yeah, my mistake - I simply glided right past the "just by macro
expansion."  Oops.  :)

>> Despite its dynamism, Lisp is quite compilable.
>
> Please correct me if I'm wrong, but as I understand,
> getting efficient code out of a Lisp compiler requires
> putting type declarations into the source.
>
> If you put the same declarations into a piece of
> Python code, then of course it would be fairly
> straightforward to compile it efficiently. But it
> wouldn't really be dynamic Python any more.

Type declarations can squeeze out extra efficiency, but vanilla Lisp
without type declarations will still beat Python, both because the
language is designed to compile well and because compilers for Lisp
are generally very mature.  So it is not the case that type
declarations are the only thing that make Lisp efficient.