DMDScript now on D2

[Dmitry Olshansky]

On 16.12.2010 19:43, Adam Ruppe wrote:
> Dmitry Olshansky wrote:
>> The goal was not only to just make it compile with D2
>> and work (that would be of limited value)
> I tried this too about a year ago...:
> http://arsdnet.net/dcode/dmdscript_d2.zip
Yes, that's the only previous effort I've found, and  it was after my 
port almost started working.

> ...but overall, from a brief glance, your port is *much* better
> than mine. I used a lot more casts and idups, and thus introduced
> new bugs and hurt the performance. I got it working, but not working
> well.
>
> Nice work!
Thanks, yet I plan a lot of refactoring, one I dream of is eventually 
replacing struct Value with Algebraic from Phobos. And yes, that 
exception propagation mechanism, I almost switched to throwing instead 
of returning exceptions from functions.
> But there still might be a few ideas or bits of code
> we can share from the easy expansion stuff.
>
> I called mine "pretty.d" and "test.d" in that zip. One of the
> things I tried to do was make a ScriptObject class in D, which
> you could expand and call with opIndex and opDispatch.
>
> I was only partially successful, but maybe we can better with
> a newer compiler.
>
> Here's a copy/paste of part of my test.d showing the idea I was chasing:
>
> =======
>          auto g = se.globalObject; // se is a ScriptEngine
>
>          /* You can work with the script environment as an associative
> array... */
>          g["hello"] = "Hello, world!";
>          g["lol"] = new ScriptObject; // ScriptObject is just a generic object.
> You can specialize it in the constructor.
>          //g["lol"]["fun"] =&fun; // Can even assign native top-level functions
> this way!  FIXME: broken due to ICE
>
>          /* Or, you can do it with opDispatch, though this is limited to just
> assigning existing ScriptObjects... */
>          auto so2 = new ScriptObject;
>          se.globalObject.lol.hate = so2;
>
>          /* You can also add functions to specific ScriptObjects with the
> addFunction template */
>          se.addFunction!(raise, "fun")(so2);
>
> =======
Yes, that's awesome. I guess I should get a closer look at that pretty.d!
> And all that stuff would of course be available to the script via
> the global object.
>
> In pretty.d, you can see some attempt to unify D and dmdscript
> exceptions too, but I don't recall how well that went, but I'm
> pretty sure it worked at least one way.
>
>
> One little thing we both did is one line expansion. One thing I'd
> add to your code is making the name of the script function default
> to being the same name as the D function. It's a minor addition,
> but I think it looks nice.

Yes, it's planned, and indeed improves user experience. I just was stuck 
with the issue of extending of variadic functions/templated functions 
consider, for example, std.stdio.writeln.  That must have distracted me 
from this issue.

>
> Generally though, your port is excellent, thanks for doing it!
-- 

Dmitry Olshansky