On Thursday, 21 May 2015 at 18:26:28 UTC, Dennis Ritchie wrote:
On Thursday, 21 May 2015 at 17:43:25 UTC, Jonathan M Davis
wrote:
No C-based language allows what python does, and based on
operators work in
C-based languages, what python is doing simply doesn't fit or
make sense.
What happens in C/C++/D/Java/C#/etc. land is that 4 <= 5
results in a bool,
at which point you'd end up with a comparison between that
bool and 6, which
is _not_ something that you want. But with other operators
_is_ very much
what you'd want. Operator chaining works in the same way
across all
operators in C-based languages, and trying to make 4 <= 5 <= 6
be equivalent
to 4 <= 5 && 5 <= 6 would make it so that they weren't
consistent. And it
wouldn't make the language any more powerful, because you can
quite easily
just do 4 <= 5 && 5 <= 6 instead of 4 <= 5 <= 6. It only costs
you a few
characters and results in the language being far more
consistent. I'm
honestly quite surprised that python would allow such a thing,
but they seem
to do a lot of stuff that most programmers from C-based
languages
(especially C++) would think is crazy.
- Jonathan M Davis
Yes, of course, some of Python's design for C ++ - programmers
will look crazy, but they are worth it :)
elif instead of else if:
http://rextester.com/WOSH30608
The parallel exchange values:
http://rextester.com/TPUD51604
Something I sometimes do for strictly personal projects:
import std.typecons : ω = tuple;
import std.typetuple : Ω = TypeTuple;
void main()
{
auto a = 1, b = 2;
Ω!(a, b) = ω(b, a);
assert(a==2 && b==1);
}
