Idea: Run Time Compilation

[Craig Black]

"Pragma" <ericanderton at yahoo.removeme.com> wrote in message
news:essjou$cks$1 at digitalmars.com...
> Craig Black wrote:
> > Since Walter is in the habit of adding super advanced features to D, I
> > thought it possible that this one might eventually make it in.  As
always,
> > please let me know if I'm way off base.
> >
> > What if we could invoke the compiler from an application at run time and
> > generate a function that would be instantiated on the heap?  The
function
> > would be defined by a text string and would be invoked via a function
> > pointer or delegate.  This would allow a script-like capability with
> > fully-optimized performance provided by the D compiler.  I think the D
> > compiler would be ideal for this since it is so fast.  Since the method
> > would be allocated on the heap dynamically, it could also be removed
when it
> > is done being used.
> >
> > Thoughts?
>
> Plenty.  I've tried my best to approach this kind of functionality for
some time in library space.  However I have my
> doubts as to having this included in D proper - since D is so minimal at
it's core, it becomes very much a library
> support problem.
>
> (I'll leave the DSP/DDL/Flectioned discussion for another thread).
>
> I can say from experience that doing this from within library space is
perfectly feasable, and yields some great
> results, at the cost of additional memory at runtime and a small (one-time
per module) delay for compilation and runtime
> binding.  I would have sooner considered drafting a runtime compiler if
DMD wasn't so fast.
>
> --
> - EricAnderton at yahoo

The run time library approach is feasible as you say, but not a efficient or
elegant as using the heap.  However, this may be possible without
modifications to the D compiler.  It would require compiling some code, then
getting the result from a file, and loading it onto the heap.  Not a trivial
task as there would be many details to work through.  But I am inclined to
believe that it could be done.  On the other hand, if Walter wanted to help,
we could probably get the compiler to emit the code directly to the heap,
which would be even better.

A run time compiler would have many applications to be sure.  One is gaming,
where a good chunk of the code is usually script.  Some game engines use
.NET or Java instead of a scripting language for better performance.  A run
time compiler would be even better.  Further, D is an ideal candidate for
such a feature because of D's compilation speed and garbage collection.

-Craig