PEP-0315--Enhanced While Loop: An idea for an alternative syntax
joe at notcharles.ca
Thu Feb 19 11:45:31 CET 2004
In article <7xfzd7v21v.fsf at ruckus.brouhaha.com>, Paul Rubin wrote:
> No, I think he's preoccupied with distinctions that aren't there.
> He said
>> x = 1 (or x := 1) looks to me like a statement that sets x to 1, not
>> an expression. I wouldn't expect any return value, if my mind hadn't
>> been corrupted by C.
> but of course from my Lisper's point of view, the whole idea that a
> statement and an expression are fundamentally different things is
> itself a sign of a corrupted mind. I'm not willing to accept the
Aha! Now I see. Python is not Lisp. It has tons of imperative
constructs that don't return values. While loops, for instance.
Corrupt or not, though, the Lisp way is "everything implicitly returns a
value". I'm not arguing for or against assignment expressions - I think
it's pretty trivial. I'm just saying you can't claim they aren't
implicit. And the Zen of Python has things to say about that.
As a Lisper, shouldn't you be avoiding assignments because of their
side effects anyway? Surely you should be pushing for "let" bindings.
Speaking of which, even though I'm not particularly interested in new
syntax - break was fine for granpappy, and it's good enough for me -
let wouldn't be a bad keyword for the initialization section of the
loop. Except that wouldn't mean exactly what it does in function
languages, which would be confusing. "with" is another possibility -
the two uses I know are Pascal, where it just makes a record alias, and
Modula-3, where it works differently but I forget how. But it's already
More information about the Python-list