Re: perplexed by blank sequence in pattern replacement
- To: mathgroup at smc.vnet.net
- Subject: [mg68729] Re: perplexed by blank sequence in pattern replacement
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 17 Aug 2006 04:18:36 -0400 (EDT)
- References: <ebuj5d$6f5$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, try Replace[a*b*c, Verbatim[Times][mysequence__] :> {mysequence}] and you got what you expect. Regards Jens Blake wrote: > Dear MathGroup: > > I have been blithely using blank sequences in pattern matching for some > time. In persuit of a bug in a package of mine, I was quite alarmed to > find that I don't really understand how to use the blank sequence, as > expressed in the following simplified example: > > In[1]:=Replace[a*b*c,Times[mysequence__]:>{mysequence}] > > Out[1]={a b c} > > I expected Out[1]={a,b,c}, from a naieve reading of the full form of > a*b*c > > In[2]:=FullForm[a*b*c] > > Out[2]//FullForm=Times[a,b,c] > > Will someone PLEASE tell me why In[1] does not yield the results I > expected? (I can readily use a work-around, what I am concerned with is > a correct understanding of pattern matching). > > Blake Laing > thesis slave > University of Oklahoma >