[v8-users] execution of eval() function returns empty value

[vlad]

Hi,
I'm confused why execution of eval() function returns empty value?

v8::Handle<v8::Function> eval_func =
v8::Handle<v8::Function>::Cast(global->Get(v8::String::New("eval")));

v8::Handle<v8::Value> args[] = { v8::String::New("/^a/i") };

v8::Handle<v8::Value> ret = eval_func->Call(eval_func, 1, args);

ret{val_ = 0x00000000} ?????


However if I do this:

V8RUN("function Foo(x) {return eval(x);}");

v8::Handle<v8::Function> eval_func =
v8::Handle<v8::Function>::Cast(global->Get(v8::String::New("Foo")));

v8::Handle<v8::Value> args[] = { v8::String::New("/^a/i") };

v8::Handle<v8::Value> ret = eval_func->Call(eval_func, 1, args);

ret is a valid RegExp object.

Thanks
Vlad




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[Stephan Beal]

On Mon, May 10, 2010 at 10:22 PM, vlad <vla...@gmail.com> wrote:
>
> v8::Handle<v8::Value> ret = eval_func->Call(eval_func, 1, args);

i _think_ what you're looking for is:

v8::Handle<v8::Function> eval_func =
v8::Handle<v8::Function>::Cast(global->Get(v8::String::New("eval")));

...
v8::Handle<v8::Value> ret = eval_func->Call(global, 1, args);

Remember that the first argument to Call() is the "this" object, and
for eval() you want that to be the global.


PS: if you are only passing only one object as the args list then you
don't need the extra intermediary array. i.e.

Call(..., 1, &theArg)

will do.
--
----- stephan beal
http://wanderinghorse.net/home/stephan/

[vlad]

Thank you!!! It works now.

On May 10, 1:43 pm, Stephan Beal <sgb...@googlemail.com> wrote:

> On Mon, May 10, 2010 at 10:22 PM, vlad <vlad...@gmail.com> wrote:
>
> > v8::Handle<v8::Value> ret = eval_func->Call(eval_func, 1, args);
>
> i _think_ what you're looking for is:
>
> v8::Handle<v8::Function> eval_func =
> v8::Handle<v8::Function>::Cast(global->Get(v8::String::New("eval")));
> ...
> v8::Handle<v8::Value> ret = eval_func->Call(global, 1, args);
>
> Remember that the first argument to Call() is the "this" object, and
> for eval() you want that to be the global.
>
> PS: if you are only passing only one object as the args list then you
> don't need the extra intermediary array. i.e.
>
> Call(..., 1, &theArg)
>
> will do.
> --

> ----- stephan bealhttp://wanderinghorse.net/home/stephan/
>
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