Re: problems compiling NSAnimation.m

[Graham J Lee]

On 10 May 2007, at 15:28, Xavier Glattard wrote:

> Richard Frith-Macdonald <richard <at> tiptree.demon.co.uk> writes:
>
> > On 10 May 2007, at 14:57, Xavier Glattard wrote:
> >
> > > Richard Frith-Macdonald <richard <at> tiptree.demon.co.uk> writes:
>
> > > > I fixed this to make __gs_isLocked an ivar rather than declaring it
> > > > locally (which was pretty suboptimal).  I also fixed a bug in the
> > > > unlock macro (it was setting the lag to the wrong value), and added
> > > > assertions to check that the macro is not misused.
> > >
> > > Bad. If __gs_locked is needed (and as i said i think it is not : i
> > > made
> > > an error) then it must be declared in all methods. If  
> > > __gs_isLocked is
> > > an ivar, its value can be changed in another method then the  
> > > [unlock]
> > > will never be called.
> >
> > Sure, but similarly if it's a local variable its value can be
> > incorrectly changed within a method or function where it is declared.
>
> If it is then you made an other programming error... ;-)
> Its name is prefixed by an underscore (and by 'gs'!) so it shouldn't
> be used by anyone.
> Moreover an ivar is more easier to be incorrectly changed...
> in an other method or even in a child class!

That's one of the reasons I suggested wrapping the whole macro in  
braces - the BOOL then becomes a local variable to the macro -  
reduces the chance of accidentally changing it by restricting the  
scope to only where it's used.

Cheers,

Graham.