Re: Pattern example
- To: mathgroup at smc.vnet.net
- Subject: [mg19309] Re: [mg19284] Pattern example
- From: "Kevin J. McCann" <kevinmccann at Home.com>
- Date: Sat, 14 Aug 1999 23:42:44 -0400
- References: <199908140545.BAA10886@smc.vnet.net.>
- Sender: owner-wri-mathgroup at wolfram.com
Chris,
Your replacement t_->c looks at the FullForm of the rest of your expression,
and takes the first object that satisfies t_ (which is anything), and
replaces it with c. Thus you end up with the "unexpected result".
i.e. {{1+a},{2+a},{3+a}} fits the bill for "t_" and so mma replaces the
whole mess, it doesn't wait to see what is inside to do the replacement.
Kevin
----- Original Message -----
From: chris <senisen at ptty.loxinfo.co.th>
To: mathgroup at smc.vnet.net
Subject: [mg19309] [mg19284] Pattern example
<snip>
> Then
> {{1+a},{2+a},{3+a}} /. t_->c
> c
> this is no more a list, but
>
> FullForm[{{1+a},{2+a},{3+a}} /. {t_}->c]
> List[c,c,c]
> shows it as a list
>
> What is behind this difference?
- References:
- Pattern example
- From: senisen@ptty.loxinfo.co.th (chris)
- Pattern example