Dual conditions in D and Python

[Dennis Ritchie via Digitalmars-d-learn]

> 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);
> }

On Thursday, 21 May 2015 at 19:05:16 UTC, Steven Schveighoffer 
wrote:
> On 5/21/15 12:57 PM, Dennis Ritchie wrote:
>> Hi,
>> In Python I can write this:
>>
>> if (4 <= 5 <= 6):
>>     print ("OK")
>> -----
>> http://rextester.com/NNAM70713
>>
>> In D, I can only write this:
>>
>> import std.stdio;
>>
>> void main() {
>>
>>     if (4 <= 5 && 5 <= 6)
>>         puts("OK");
>> }
>> -----
>> http://rextester.com/FICP83173
>>
>> I wanted to ask what is the reason? Maybe the program on 
>> Python's slower
>> because of this? Or legacy C/C++ affected D?
>
>
> There is this possibility:
>
> switch(5){
>    case 4: .. case 6:
> }
>
> You could also make some nifty abuse-of-syntax types:
>
> struct Between(T)
> {
>    T low;
>    T high;
>    bool opBinaryRight!(op : "in")(T val) { return val >= low && 
> val <= high;}
> }
>
> auto between(T)(T low, T high) { return Between!T(low, high); }
>
> if(5 in between(4, 6))
>
> :)
>
> -Steve

All this, of course, looks good, but what about the principle of 
the ideal programming language :)

"In the end I want to focus on one philosophical principle, which 
lies at the basis of my ideas about the ideal programming 
language. Typically, during the discussion in the forums, when 
you start to talk in a language that is not X features Y, be sure 
there is someone who will say: Why, that's if you take the 
features A, B and C, and screw them crutches D, E, F, then we 
will get almost Y. Yes, it is. But I do not like this approach. 
One can imagine that such programmers want some complicated way 
through the maze. You can go through the maze, but the way the 
curve and non-obvious. I also want to be instead of the labyrinth 
has a large area, on which from any point to any other one would 
go in a straight line. Just a straight line."
-----
The quotation is taken from the article:
http://habrahabr.ru/post/257875/