[Python-ideas] if condition: break idiom
arnodel at googlemail.com
Sat Sep 20 21:54:59 CEST 2008
On 20 Sep 2008, at 20:07, Brett Cannon wrote:
> On Sat, Sep 20, 2008 at 11:35 AM, Arnaud Delobelle
> <arnodel at googlemail.com> wrote:
>> [...] I think that this would look better:
>> while True:
>> do something
>> break if condition
>> do something else
> For some reason this suggestion reminds me of Icon.
> Anyway, so I take it this suggestion is to extend the break statement
> to have an 'if' trailer? Or are you trying to make 'break' an
No I wasn't suggesting this.
> If you are after the former, the problem with that is that the
> special-casing of 'if' might confuse people because they will suddenly
> want an 'else' clause. Adding that might then cause a naive user to
> see ``break if x`` and then think 'break' is an expression.
I thought that the meaning of e.g.
break if x < 1
was clear and unambiguous.
I don't know if some people do, but I personally have never felt the
need to write something like:
expression1 if condition else expression2
on its own on a line. So I wouldn't find the above 'break if x < 1'
statement confusing :)
> Which leads to its own issues. How do you implement 'break' as an
> expression? It doesn't make much sense to have ``fxn(a, break, b)``
> inside a loop. And you can't say 'break' can only appear in the true
> clause of an 'if' expression as that is too specialized and will lead
> to potential misuse of the statement (or at least an attempt).
I certainly wouldn't want 'break' to be an expression.
> I don't see enough benefit from the change to warrant dealing with any
> of the above issues.
More information about the Python-ideas