Add partitioning functions to Data.List

The functions take and span have recursive equivalents takeRec and spanRec that apply the same function to the remainder, i.e.

takeRec i xs = let (hs,ts) = splitAt i xs in hs : takeRec i xs
spanRec p xs = let (hs,ts) = span    p xs in hs : spanRec p xs

and the more generic version of take:

genericTakeRec i xs = let (hs,ts) = genericSplitAt i xs in hs : genericTakeRec i xs

These functions, to me, are in the same league as partition and group, can be added with little chance of nameclashes on functions with a different meaning and are not named compositions.

Trac metadata

Trac field	Value
Version	6.12.1 RC1
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	libraries/base
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture