Re: libseed-list module import suggestion

[Jonatan Liljedahl <lijon kymatica com>]

Here's another way, a lot simpler!

//testmodule.js

(function() {
    var y = 42;

    this.x = 123;
    this.f = function() { print(__script_path__+y) };
})();

//somescript.js

t=imports.testmodule;
t.y;     //undefined
t.x;     //123
t.f();   //somepath42

Jonatan Liljedahl wrote:
> Sure, that's one way to do it, but I still think that the seed importer 
> should be a bit more clever and not just import everything. You 
> shouldn't need to make work-arounds like below for such a basic 
> functionality. In most cases, you don't want to export the entire global 
> object but just selected variables.
>
> /Jonatan
>
> Alan Knowles wrote:
> > I had quite a long play with that as well, in the end I came up with
> >
> > File.js
> > --------------
> > var _my_private_var
> > var _my_private_var2
> > var _my_private_var3
> > ...
> >
> > var File = {
> >    read: function() { }
> >    ...
> > }
> > ================
> >
> > Usage
> > File = imports.File.File;
> >
> > --------------------------------
> >
> > While not perfect (double typing the Class name..), It trades off 
> > quite a few issues..
> >
> > * Privates are generally private until you absolutely do not want them 
> > to be (this is very common that you need to find out what the privates 
> > contain. If you enforce hiding at runtime, it becomes very complex to 
> > test and debug).. especially since seed does not anything resembling 
> > have a debugger at present..
> > eg. I can print imports.File.File._my_private_var if something wierd 
> > is happening..
> >
> > * It's reasonably clear what's happening.. - no hidden magic, 
> > requirement for documenting strange behavior...
> >
> > * enables you to do static classes, using 'this' to point to the 
> > static instance..
> >
> > * There is no layer of complexity meeded in the engine (always a good 
> > idea to avoid)
> >
> > Anyway there's a 2c viewpoint....
> >
> > Regards
> > Alan
> >
> >  --- On 14/Jun/2010, Jonatan Liljedahl wrote:
> > > Currently, importing another JS file imports all toplevel variables. 
> > > This is not very nice, since you can't have private stuff without 
> > > resorting to some hack like this:
> > >
> > > var _exports = (function() {
> > >      var x = 123;
> > >      var y = 42;
> > >      var f = function() { print(x) };
> > >
> > >      return {
> > >          y:y,
> > >          f:f
> > >      }
> > > })();
> > >
> > > for(var k in _exports) {
> > >      this[k] = _exports[k];
> > > }
> > >
> > > I suggest that if a variable EXPORTS is found, only the symbols 
> > > listed in it will be exported:
> > >
> > >    EXPORTS=[foo,bar,x,y];
> > >
> > > seed_importer_handle_file() would then do something like this:
> > >
> > >    if global.EXPORTS exist and isArray:
> > >       exports = newEmptyObject()
> > >       for each s in EXPORTS:
> > >          exports[s] = global[s]
> > >    else:
> > >       exports = global
> > >
> > >    return exports
> > >
> > > One could additionally have a naming convention where symbols 
> > > prefixed with underscore is ignored unless EXPORTS is defined.
> > >
> > > What do you think?
> > >
> > > /Jonatan
> > > _______________________________________________
> > > libseed-list mailing list
> > > libseed-list gnome org
> > > http://mail.gnome.org/mailman/listinfo/libseed-list
> >
> > _______________________________________________
> > libseed-list mailing list
> > libseed-list gnome org
> > http://mail.gnome.org/mailman/listinfo/libseed-list