Re: Pattern to match a list of non-negative integers

*To*: mathgroup at smc.vnet.net*Subject*: [mg108944] Re: Pattern to match a list of non-negative integers*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 8 Apr 2010 07:59:19 -0400 (EDT)

MatchQ[{2, 3}, x : {_Integer?NonNegative ..}] True MatchQ[{2, 3}, x : {_?(IntegerQ[#] && # > 0 &) ..}] True Bob Hanlon ---- Leo Alekseyev <dnquark at gmail.com> wrote: ============= This seems like a very basic pattern-matching question, but somehow the answer eludes me at the moment. I want to match a list of non-negative integers. Something like MatchQ[{1,2},{(x_Integer /; x >= 0)..}] doesn't work -- do named patterns simply not play well with Repeated[]?.. After starting to write this message, the following pattern, occurred to me: MatchQ[{2, 3}, x : {_Integer ..} /; ! MemberQ[x, y_ /; Negative[y]]] -- this works, but seems needlessly complex -- so I'll send the message on, in hopes that there is a cleaner way of writing the pattern.