On Tue, Sep 28, 2010 at 9:57 AM, Ian Lynagh
I don't understand why the number of functions is such an issue. To me, ease of use is more important.
But more functions hurts ease of use! An API gets harder to grasp the more functions it has and knowing which function to use gets harder when the number of functions increases. OO map data type get away with about 10-15 functions, we have 150! I've written about this topic before on haskell-cafe. That post contains a somewhat more thorough arguments for not adding too many functions to APIs. Let me know if you can't find it. (There is also an maintenance cost, but it's not as important as the cost to API users).
For example, (assuming the performance is, or could be made, the same), would Data.List be improved by removing concat and map, as they can be written as (concatMap id) and (concatMap . (return .))?
If we would remove any of these three functions it would be concatMap as it's a simple function composition of the concat and map! The only reason I can see for having concatMap is that it's >>= for lists. -- Johan