Subj : Re: Stuck with the basics
To   : netscape.public.mozilla.jseng
From : "Stu" <stu.email@emailme.com>
Date : Fri May 23 2003 10:51 am


"Brendan Eich" <brendan@meer.net> wrote in message
news:3ECD0616.8010407@meer.net...
>
> > char functionscript[4000];
> >
>
> You don't need to copy a string literal into a way-oversized array.
>
> > char *argnames;
> >
>
> Should be const char *argnames[1]; or something like that.
>
> >rt = JS_NewRuntime (10000000L);
> >cx = JS_NewContext(rt, 8192);
> >JS_SetErrorReporter(cx, my_ErrorReporter);
> > glob = JS_NewObject(cx, &global_class, 0, 0);
> > builtins = JS_InitStandardClasses(cx, glob);
> >
> >  /*
> >   * Define an object named in the global scope that can be enumerated by
> >   * for/in loops.  The parent object is passed as the second argument,
as
> >   * with all other API calls that take an object/name pair.  The
prototype
> >   * passed in is null, so the default object prototype will be used.
> >  */
> >  localobj = JS_DefineObject(cx, glob, "localObject", &its_class, 0,
> >                          JSPROP_ENUMERATE);
> > if (!JS_DefineProperties(cx, localobj, its_props))
> >  return 1;
> >
> >strcpy (functionscript, "function Hello() {var hi = \"Hello World\";
return
> >hi.toString();}");
> >lineno = 0;
> >
> >functionptr = JS_CompileFunction(cx, glob, "Hello()", 0, &argnames,
> >functionscript, strlen(functionscript), "default.pac", lineno);
> >
>
> You've just compiled a function whose *body* is 'function Hello() {var
> hi = "Hello World"; return hi.toString();}' -- in other words, you've
> just compiled a function Hello that contains another function named
> Hello, as if you typed this into the JS shell:
>
> function Hello() {
>   function Hello() {
>     var hi = "Hello World";
>     return hi.toString();
>   }
> }
>
> > rval =0;
> > executed = JS_CallFunction(cx, glob, functionptr, 0, jsargv, &rval);
> >
>
> You just called the outer Hello() and it returned undefined, because it
> contains no statements, only an inner function declaration.
>
> >
> >str = JS_ValueToString(cx, rval);
> > JS_AddRoot(cx, &str);
> >  printf("Call function script result: %s\n", JS_GetStringBytes(str));
> >
> >this prints Call function script result: undefined to the console.
> >
>
> That's the correct result.
>
> /be

THANK YOU!
You do not know how relieved I am!
There is NO documentation of this anywhere! If you go down the wrong path
the first time you're screwed for ever more.
cheers again,
Stu

.