Re: match 1, replace 2
- To: mathgroup at smc.vnet.net
- Subject: [mg56244] Re: match 1, replace 2
- From: "Carl K. Woll" <carlw at u.washington.edu>
- Date: Wed, 20 Apr 2005 05:30:31 -0400 (EDT)
- Organization: University of Washington
- References: <d42khj$3ac$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
"Trevor Baca" <trevorbaca at gmail.com> wrote in message news:d42khj$3ac$1 at smc.vnet.net... > hi mathgroup, > > what rule takes > > ls = {{1, 2, 3}, {4, 5}, {6, 7, 8, 9}} > > to > > {{101, -1, 102, -1, 3}, {104, -1, 5}, {106, -1, 107, -1, 108, -1, > 9}} > > ie, matches all integers but the last in each list and then replaces > each matched integer n with the 2-element sequence Sequence[100 + n, > -1]? > > trevor. > Here is one possibility. n=101; ls /. {a__Integer, b_Integer} :> Append[{a} /. c_Integer:>Sequence[n++,-1], n++; b] {{101, -1, 102, -1, 3}, {104, -1, 5}, {106, -1, 107, -1, 108, -1, 9}} Carl Woll