Re: Lost myHead, please help !!!
- To: mathgroup at smc.vnet.net
- Subject: [mg22371] Re: Lost myHead, please help !!!
- From: "Allan Hayes" <hay at haystack.demon.co.uk>
- Date: Sat, 26 Feb 2000 22:04:58 -0500 (EST)
- References: <897drf$5q0@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Antoine: x = {{a}, {b, c}}; Apply[myHead, x] myHead[{a}, {b, c}] Abbreviation for Apply is myHead @@ x myHead[{a}, {b, c}] And we can use ReplaceAll, but with a more discriminating pattern x /. List[e___] -> myHead[e] myHead[{a}, {b, c}] Please note the search for parts to replace is top-down along branches, and that having replaced {{a},{b,c}} with myHead[{a},{b,c}],no further work is done on the new part, even though {a} and {b,c} both match List[e___]. "Antoine Zahnd" <antoine.zahnd at iprolink.ch> wrote in message news:897drf$5q0 at smc.vnet.net... > Hello everybody, > > I can't do the following (sigh) > > Let x = {{a},{b,c}} > > I would like to tranform it into something like myHead[{a},{b,c}] > > Of course x /. {List->myHead} doesn't work ! > > Certainly it is simple, but so far I didn't get it. > > Thank you for your help. > > antoine.zahnd at iprolink.ch > > >