Bug or feature?
James Henderson
james at logicalprogression.net
Fri Jan 16 11:13:06 EST 2004
On Friday 16 January 2004 2:44 pm, Alexey Nezhdanov wrote:
<snip>
> I know the case where such python behaivoir causes hard-to-catch problems.
> I do not know any case (anybody knows? please give example) where such
> "feature" may be useful.
>
> So I proposing to make a change into python and reverse the order of
> calculations.
> Just for sure:
> === Order used now ===
> ## a+=a.Sub(b)
> 1. evaluate value of 'a'
> 2. evaluate value of 'a.Sub(b)'
> 3. evaluate the sum
> 4. store the result into 'a'
> === Proposed order ===
> ## a+=a.Sub(b)
> 1. evaluate value of 'a.Sub(b)'
> 2. evaluate value of 'a'
> 3. evaluate the sum
> 4. store the result into 'a'
-1
In any language that uses such an operator I would expect:
a += b
to be synonymous with:
a = a + b
You are suggesting that it should mean:
a = b + a
It is not like Python to attach its own idiosyncratic semantics to operators
already well known from other languages. I think this would catch a lot of
people out.
Of course, it's probably best to avoid writing code where the order makes a
difference. :)
James
--
James Henderson, Logical Progression Ltd.
http://www.logicalprogression.net/
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