Just to clarify for those on the sidelines, the issue is duplication of implementation details, rather than duplication of functionality?
Well to me, that is not the main issue. The main issue is that you have to study all of them and depending on which libraries you want to use have to convert between them, which could be expensive and is definitely annoying. I made a few simple benchmarks comparing the three libraries you can find the code attached. this is compiled with -O2 # simple sum of 1000000 Word8 elements Unboxed Vector 1.114060 ms Storable Vector 795.1207 us Primitive Vector 1.116145 ms ByteString 9.076256 ms array library has no fold or sum function # simple sum of 1000000 more or less randomly chosen elements Unboxed Vector (unsafe) 33.74364 ms Storable Vector (unsafe) 50.27273 ms Storable Vector (safe) 67.01634 ms Primitive Vector (unsafe) 56.29919 ms ByteString (unsafe) 19.29611 ms ByteString (safe) 18.29065 ms UArray (safe) 46.88719 ms unsafe does not exist for array So Unboxed can be better than Storable but doesn't need to be. Also, which implementation is faster depends very much on the problem at hand. And array is just missing half the needed features. Silvio