D const design rationale

[Walter Bright]

Daniel Keep wrote:
> 
> Walter Bright wrote:
>> ... A lot of people use Python, and are forced
>> to mix in C++ to speed up the slow parts. It would be much simpler for
>> them if they could use the same language for both.
> 
> I'll have to disagree on this.  I used Python for my third year
> comp.sci. group project, and it made things a hell of a lot easier.
> Most of the code was dealing with the GUI, with only a few math-heavy
> parts written by myself.
> 
> Using Python for the mathy parts made them so much easier to debug it
> wasn't funny, and I've never seen anything that could touch Python for
> writing sane GUI code.
> 
> In the end, I had to convert some of the slower code from Python to C,
> but that was basically a trivial exercise.  Pyrex allows you to write
> "Python-like" code that compiles directly to C that makes writing the
> native module wrapping C code a non-issue.
> 
> If I'd used just C++, the GUI coding would have driven me completely
> insane.  If I'd been restricted to an interpreted language, our app
> would have been slow as molasses.  By using Python, we got the best of
> both worlds :)

Everyone knows that C++ sucks for writing GUIs, I hope to do much better 
with D.

> 
> In a wacky kind of way, one of the reasons I chose Python was *because*
> it could be easily optimised.  True, it had to be done in a different
> language, but there was almost no effort required to do so, so I never
> had to fear hitting a performance ceiling.

But you did hit a performance ceiling. You had to convert the 
bottlenecks to C. Wouldn't it be nice not to have to do that? <g>