eval() (Was: One more update on d-programming-language.org)

[Philippe Sigaud]

On Wed, Sep 15, 2010 at 22:19, Nick Sabalausky <a at a.a> wrote:

> One thing that could be used for that is the eval() function I've recently
> added to my SemiTwist D Tools library:
>
>
> http://www.dsource.org/projects/semitwist/browser/trunk/src/semitwist/util/process.d
>
> Example:
> -----------------------------
> import semitwist.util.all;
> void main()
> {
>    auto x = eval!int(q{ return 21 * 2; }); // String can be
> runtime-generated
>    assert(x == 42);
>
>    eval!void( q{ writeln("Hello World"); }, q{ import std.stdio; } );
> }
>

Oh, interesting!
I had a look at your code. I like this part:

code = boilerplate.format(imports, TRet.stringof, code);

Inside boilerplate, I wonder if it's possible to test for auto ret = _main()
inside a static if(is(typeof(  )))? That way, if _main() 'returns' a void,
the static if won't check and you know you have a void return value.







> -----------------------------
>
> It does require dmd and rdmd to be on the path.
>
> I hadn't posted anything about it before because it's still
> rough-around-the-edges and needs polish. For instance, most of the useful
> phobos modules aren't imported by default, and it doesn't yet support
> returning string/wstring/dstring - you have to return
> char[]/wchar[]/dchar[]
> instead and then convert back to string/wstring/dstring (but that shouldn't
> be too hard to fix). Also, on Windows it requires a patched version of
> rdmd,
> which is included with the library (
> http://www.dsource.org/projects/semitwist/browser/trunk/rdmdAlt.d ) but
> eval
> doesn't yet compile it if it isn't already compiled, and it assumes it's on
> the path (I've already solved both of these in the included stbuild
> program,
> I just need to move the solution over into the general library). My
> ultimate
> goal with this is to hack up DMD just enough to make it work at
> compile-time
> (so that *any* arbitrary code can be run at compile-time, albiet more
> awkwardly and with much more overhead than ordinary CTFE).
>
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puremagic.com/pipermail/digitalmars-d/attachments/20100916/1ab999ac/attachment.html>