Re: mutter tiling

[Oliver Mangold <o mangold googlemail com>]

On 17.03.2011 13:31, Jasper St. Pierre wrote:

> >   Me personally, I'm not in favor of writing writing it
> > in Javascript because of the dynamic typing (will be painfull to find
> > problems caused by changed Mutter bindings).
> Why do you think that?
Standard problem of dynamically typed languages. Checking if variables 
have the right type is delayed until runtime. Example (pseudocode):

windows = global.get_windows()
mutter_window = windows[0]
meta_window = mutter_window.get_meta_window()
meta_window.move(100,100,200,200)

This code assumes that the object global has a method
    MutterWindow[] get_windows()
that the class MutterWindow has a method
    MetaWindow* get_meta_window()
and that the class MetaWindow has a method
    void move(int x,int y,int w,int h)

If you change then to a new version of gnome-shell or mutter where 
anything from this interface is changed, in javascript you get an 
runtime error only when a statement using it is actually executed. This 
means for every update of the framework, to be reasonably sure that your 
plugin still works you have to test it completely (with 100% code 
coverage). This is big fun, as we are talking about GUI stuff here, so 
you can't even run it automatically.

In Vala you get a compiler error as soon as you try to compile your 
plugin. Which do you think is better? :)

> There's no support for running various C code from an extension right
> now, either compiled through Vala or not.
Too bad. Another statically typed language maybe?