in reply to using constants in Derived class
I'd like to bring some curious implementation details to your attention:
- use constant works by automatically generating nullary subroutine that returns a constant. The optimizer then optimizes away the call, and replaces it by the constant itself.
- All subroutines can be used as method
- In method calls, the arity check from the prototype that use contant ... installed isn't performed
Combining these curious features, you'll notice that
- If there was use constant a => 1 in a class, you can actually access that value with $obj->a
- If a child class has another use constant a => 2;, the $obj->a syntax returns the value from the derived class
So if you access the constant as methods, everything should work according to your wishes. What a coincidence :-)
That way it's much more extensible than using a big if-elsif-else construct, and I consider that a good thing. It's a typical OO style, and if your application is already OO, it's good to conform to that stlye.
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