Andrew Coppin schrieb: > Haskell has ADTs. Most of the time, these work great. As I've written in > several other places (but possibly not here), OO languages tend to > "factor" the problem the other way. That is, if I want a binary tree, an > OO language makes me split the type and all of its operations into three > parts (an abstract base class, a branch subclass, and a leaf subclass). > Adding each new operation requires adding an abstract version of it to > the abstract base class, and putting half of the implementation into > each concrete subclass.
I think, that's known as the 'expression problem'. http://en.wikipedia.org/wiki/Expression_problem _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
