const

[Walter Bright]

Georg Wrede wrote:
> Walter Bright wrote:
>> We're just on the cusp of a huge push towards multiprogramming. We 
>> have to be ready for it, or we'll be left in the dustbin of history.
> 
> I massively agree here. While I've said that I personally don't use
> const, I still think pursuing const, const-correctness, and const
> transitivity are definitely a top priority for D.
> 
> My take on it is, _because_ const transitivity is _hard_ to patch onto
> C++, Java, etc., _and_ it seems to be within reach for D, that alone is
> reason enough to give it our best shot. (If it turns out later that not
> even we can do it, then so be it. But 5 years from now, we'd crucify
> ourselves for not having tried, if it turns out it's been done in any of
> those languages, even half-bakedly.)

That cusp means that people are (even now) leaving C++ and Java and 
looking for multiprogramming languages. This is going to soon turn into 
a flood. This is a major window of opportunity for D. Haskell and Erlang 
are the current beneficiaries of that, and C++0x has a rather mad 
scramble going on just to acknowledge the existence of multiprogramming 
in the Standard.


> Since Java is only on a VM (the last physical CPU to run Java natively 
> was, I guess, my Java Ring that I got from a convention, years ago...), 
> it is interesting that they didn't run multithread stuff already in the
> nineties on a regular basis to get experience on multithreading.
> 
> How hard can it be to write a two- or even eight-virtual-processor VM?
> Basically all you need is a 386 (albeit "overclocked"). The VM would of
> course fake the multi thing, but still.
> 
> Would've given them a head start.

People were doing multiprogramming with Java from the beginning. That's 
why it has synchronized functions, volatile, etc. The thing is, we have 
10 more years of experience with what works and what doesn't work with 
multiprogramming, so we can do a much better job.