Re: match 1, replace 2
- To: mathgroup at smc.vnet.net
- Subject: [mg56240] Re: match 1, replace 2
- From: Peter Pein <petsie at arcor.de>
- Date: Wed, 20 Apr 2005 05:30:17 -0400 (EDT)
- References: <d42khj$3ac$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Trevor Baca wrote:
> 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.
>
In[1]:=
ls = {{1, 2, 3}, {4, 5}, {6, 7, 8, 9}, {0}};
In[2]:=
ls /. {f___Integer, g_Integer} :>
Append[Apply[Sequence, ({100 + #1, -1} & ) /@ {f}, {1}], g]
Out[2]=
{{101, -1, 102, -1, 3}, {104, -1, 5}, {106, -1, 107, -1, 108, -1, 9}, {0}}
--
Peter Pein
Berlin