Re: Split in Mathematica 2.2

*To*: mathgroup at smc.vnet.net*Subject*: [mg12840] Re: Split in Mathematica 2.2*From*: Andrzej Kozlowski <andrzej at tuins.ac.jp>*Date*: Wed, 17 Jun 1998 00:27:47 -0400*Sender*: owner-wri-mathgroup at wolfram.com

For any one who interested in this topic: here is quite fast functional program which simulates Split and works in Mathematica 2.2. It's based on the same idea as Xah Lee procedural code: find the places where the sequence should be split, insert markers and use Take. My earlier version had a couple of bugs in it: it did not work when elements were themselves lists (pointed out by Xah Lee) and got into trouble if the list contained a repeat element at the beginning. This one should work always (I hope). split[l_,fQ_:SameQ]:= Module[{m,H}, Map[Take[l,#]&, Partition[ Insert[Insert[ Flatten[ Position[ Partition[Map[#/.List->H&,l],2,1]/.{x_,y_}/;Not[fQ[x,y]]-> m,m]],0,1],Length[l],-1],2,1]/.{a_,b_}->{a+1,b}]/.H-> List] Andrzej Kozlowski