I would do something like:

Color named: #red.
Color named: #blue.

et cetera.

the implementation of named: is a dictionary lookup.

Color class>>named: aSymbol
^self colors at: aSymbol

And the colors dictionary is a class instance variable that is lazily initialized by its accessor.

Pros are that there is no endless lists of methods at class side, and by using the accessor with lazy init there is no risk for the class instance variable to be nil because of class initialization weirdness. (Not that there is a bug with it, but I am not happy with my  understanding of when this happens.)

On Mar 23, 2016, at 13:41, Peter Uhn��k <i.uhnak@gmail.com> wrote:

Hi,

as this probably doesn't have one solution I am interested in your approach, if you have any.

The problem is that often you want to create instances (or just return constants) in some particular domain, e.g.

Color red.
Color blue.

Unfortunately this doesn't scale, because putting unary methods on the class-side is a good way to break your image.



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Johan Fabry   -   http://pleiad.cl/~jfabry
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