Even if you put the method on the class-side, you would still be
creating an new instance each time. Maybe you can store it in a class
variable...
MyRectangle>>oppositeSides
^ oppositeSides ifNil: [ oppositeSidesCache := { #top -> #bottom.
#bottom -> #top.
#topLeft -> #bottomRight
....
} asDictionary ].
cheers -ben
On Thu, Jul 23, 2015 at 8:40 AM, Peter Uhnak <i.uh...@gmail.com> wrote:
> Hi,
>
> I am trying to figure out where to best place some mapping/data/stable
> methods.
>
> For example imagine method
> ~~~~~~~~~~~~~~~~~~~~~
> MyRectangle>>oppositeSides
> ^ { #top -> #bottom.
> #bottom -> #top.
> #topLeft -> #bottomRight
> ....
> } asDictionary
> ~~~~~~~~~~~~~~~~~~~~
>
> And then the class might have some other related methods such as
> ~~~~~~~~~~~
> MyRectangle>>oppositeSideFor: aSide
> ^ self oppositeSides at: aSide
> ~~~~~~~~~~~~
>
> So it's a method returning a mapping between opposite sides/corners and thus
> is really not going to change.
> Now I could place this in instance-side and create a new instance every time
> I wanted to use it (which doesn't seem practical), or I could put it in
> class-side.
> The problem I have with class-side is that naming is more like going through
> minefield (more than once I corrupted my image by naming a method or
> variable something I shouldn't have), and for whatever reason it feels like
> either metaprogramming or procedural programmming... That class side methods
> are pretty much global functions/variables... and short of constructors I am
> avoiding static methods even in other languages... but maybe using it is ok.
> Or maybe have it object an use singleton?
>
> The only oop-like approach I see would be to extend symbols (#top
> oppositeSide), or have separate objects for sides, but that seems like
> overkill.
>
> MySide subclass: #Top
>
> Top>>oppositeSide
> ^ Bottom new
>
> Are there any best practices regarding this? This is also true for actual
> data stored in methods/attributes (such as icons).
>
> P.s.: For english natives... Should the second method be ned
> "oppositeSideOf:" or "oppositeSideFor:"?
>
> Any ideas/pointers appreciated,
> Peter
