On 9/6/10 12:53 PM, John Lato wrote:
I'd like to make one more argument in favor of my preference for more splitting of type classes.
FWIW, I agree that more splitting is generally good. This is one of the problems I have with the various proposals for a ListLike class. They conflate the cons-list like, sequence like, string like, set like (i.e., Boolean algebra), and collection like (e.g., filterable) functions with nary a care. This in turn means that fewer types can implement the class, and moreover that we can state fewer properties about the instances which are there (e.g., what their running time complexity is or should be).
The countervailing force, for me, is the question of whether the smaller classes can still be well-defined--- as discussed separately in the "Pointed" thread fork. If MPTCs are involved, the other consideration is to make sure that type inference for common usage isn't borked by splitting things. Even though it's a common argument from others, I don't care about defining one instance with five methods vs five instances with one method each. This last argument seems to be one of the leading problems with redefining the numeric hierarchy.
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