On Sunday, 17 February 2013 at 09:47:08 UTC, Russel Winder wrote:
Sorry to come to this thread late, and apologies if I am
missing the
real point to this thread.
On Sun, 2013-02-17 at 10:13 +0100, js.mdnq wrote:
On Sunday, 17 February 2013 at 07:53:15 UTC, Walter Bright
wrote:
> On 2/16/2013 7:26 PM, js.mdnq wrote:
>> Would it ever be possible to compile D source directly to
>> java to take advantage
>> of what java offers. (e.g., the ability to run d code
>> inside a browser)
Running Java in the browser is now unlikely to ever happen
again. If
anything the target should be JavaScript or Dart, and even Dart
would be
a huge risk.
>> I'm not talking about necessarily fully fledged
>> functionality(obviously stuff
>> like asm isn't going to work) but basically the ability to
>> use D's syntax and
>> some of it's compiler features(mixins, templates, etc).
A lot of work is going into creating Python executability in
browsers.
Skulpt, Brython, etc., but traction is minimal. Browsers mean
HTML5 and
ECMAScript (aka JavaScript)
>
> Java doesn't have pointers, so right off the bat there'd be
> big problems.
Java does have pointers... you just can't get to them easily.
At the very least, you could allocate and manage your own
chunk of memory and do all the pointer arithmetic yourself on
that chunk. This would require the chunk to be pinned in some
way and the GC to be turned off but it is an option.
There is the possibility of using NIO2 buffers in ways that
were never
envisaged. This is effectively what happened in RTSJ, which was
a
real-time systems framework using Java and JVM. RTSJ sadly was
too far
ahead of its time and so died. The last vestige will die when
the Mars
Rover does.
Also, have you looked much at sun.misc.Unsafe?
You really don't want to go there ;-)
Obviously for garbage collection and concurrency and
parallelism control
you have to go there so as to subvert the JVM object model. The
question
is that unless you are working on the G1 garbage collector or
java.util.concurrent primitives, is there any point?
Or maybe one could use the JNI to write an external memory
manager for each platform and all pointer arithmetic is passed
through that. Of course, if one goes this far then any "javaD"
would need to be able to work well with importing java
libraries to be of any use.
Sounds like a mountain rather than a molehill. We are looking at
something vaguely analogous to get CUDA and OpenCL working from
GPars/Groovy/Java. Good for users, very ugly for implementors.
Unless there is a mapping of the semantics of a language to the
intermediate code of the platform, then it is better not to
bash head on
wall but to go put energies into something more productive. If
the D
semantics cannot be mapped down to the JVM bytecodes, then D is
not a
language you want to run on the JVM. Given
Java/Scala/Kotlin/Ceylon/Groovy as the static languages and
Groovy/JRuby/Jython/Closure as the dynamic languages (yes
Groovy is
correctly in both categories!) is there really a market for a
minor
player native code language trying to ease itself onto the JVM
platform?
The world is split into native code, PVM, JVM,
JavaScript/ECMAScript. D
only really has a play in one of these, and needs to get real
traction
there first before looking for new lands to conquer. Else it
risks being
seen as a solution looking for a problem to solve.
Everything started out as minor and if D's language features are
truly good and D is as well designed as some think then people
will migrate to it. Essentially "If you build it they will come"
type of scenario.
Those that would use a D for java type of language can't so there
is no way to measure how successful it would be.
Virtual machine programming has many benefits but we definitely
do not need another one. Hence, it would be nice to leverage
java, which already has build up it's user base to further the D
language paradigm. I like D but so far it doesn't seem to be
going anywhere. Why? Because one already has all these other
languages and tools to do the job.
Imagine this:
Suppose with a snap of your fingers you could have the following
products:
High stable and performant D compiler for all the major
platforms(including many embedded) with a large collection of
support tools.
A D virtual machine that runs on many platforms. A D for java
compiler that compiles almost any D program into java bytecode
and use java libraries.
etc...
Now, if you had all this stuff magically out there do you think
that the userbase for D would explode? I do... In fact, it would
happen for most decent languages. (of course, we could argue
about the exact details but D would become a major player within
a few years)
Hence, having this stuff is important for D's success. Of course,
it may not be possible in some cases or sacrifices have to be
made. In any case I'm not convinced that a D for java can't be
implemented and I do feel it would further D's popularity.
Of course, D is still in it's infancy but it would be cool it
someone was interested in trying to make a D for java and see
where it goes. I think something useful would come out of it.
(Please don't say I should do it either...)
