Perl is worse!

[Alex Martelli]

"Paul Boddie" <paulb at infercor.no> wrote in message
news:39814767.FFEFE5D0 at infercor.no...
    [snip]
> > 1 + "foo" = string ("1foo")
>
> Doesn't Perl do this last one as well? I refer you to the example I give
above -

Nope; in Perl, 1 + "foo" is 1.

> to have such behaviour permeating one's code is "nasty" to say the least.

I do consider it impractical, but what's "nasty" about it?


> > 1 + 1j = complex
> >
> >     So please don't tell me you don't want "automagic" type changing
when it
> > is already there and, I'd wager, you use it extensively.
>
> Actually, this kind of thing does irritate some people, but at least one
can
> claim that such behaviour for numbers is more or less accepted in wider
circles,

Specifically: in mathematics, there is a natural injection from naturals to
integers, from integers to rationals, from rationals to reals, from reals to
complex.  Unfortunately, things are *NOT* all roses and wine in the
real world, because we don't really have rationals in Pythons (much less
reals, of course:-), but rather an approximation -- so, precision-loss,
which is a form of information-loss, threatens...:

>>> long(12345678901234567890123L*1.0)
12345678901234567741440L

While it takes the explicit 'long' converter to see it clearly, the
information
loss has really happened in the implicit and silent conversion of
long-integer
(unlimited-precision) to floating-point (limited-precision).  Now *THAT*
is nasty!-)  I guess not enough people use a lot of long-integers, so
they're
rarely bitten by this -- but I do a lot of combinatorics, where
long-integers
are a real blessing, thus, the IMPLICIT information-loss in long->float
conversion forces me to be *EXTREMELY* careful.   Now if we had
unlimited-precision *rational* numbers, with both long-integers and floats
getting implicitly and silently promoted to suitable such *rationals*, the
world would be a very nice place again...:-).

> whereas 1 + "foo" is meaningless to almost everyone except Perl coders.

No way -- it's perfectly valid in C, too, except that there it means the
constant-string "oo".  Really, truly, X my heart, I kid you not, check it
out if you don't believe me (I wouldn't blame you for disbelieving this!).


Alex