Proposal: Add split and splitWith (trac #2048)

[Twan van Laarhoven]

Ian Lynagh wrote:
> One or the other should be changed so that these agree:
> 
> *Main> split 'a' ""
> [""]
> *Main> Data.ByteString.Char8.split 'a' (Data.ByteString.Char8.pack "")
> Loading package array-0.1.0.0 ... linking ... done.
> Loading package bytestring-0.9.0.1 ... linking ... done.
> []
> 
> although I couldn't say which is "right" OTTOMH...

I hadn't noticed. In my opinion the Data.List version is more consistent,

 > split 'a' "xx" == ["xx"]
 > split 'a' "x"  == ["x"]
 > split 'a' ""   == [""]

and

 > split 'a' "aa" == ["","",""]
 > split 'a' "a"  == ["",""]
 > split 'a' ""   == [""]

Versus:

 > B.split 'a' "xx" == ["xx"]
 > B.split 'a' "x"  == ["x"]
 > B.split 'a' ""   == []
 > B.split 'a' "aa" == ["","",""]
 > B.split 'a' "a"  == ["",""]
 > B.split 'a' ""   == []

Twan