* Joseph Wright <[log in to unmask]> [2012-02-02 10:44:09 +0000]: Hi Joseph, : There is certainly nothing at present in l3kernel to do this. What I am : not sure of here is a use case: these seem somewhat unusual functions. : : Although it is not yet in l3kernel, I wonder if this is a job for the : l3regex module that Bruno has written. Using a regex, it is possible to : specify complex token list requirements without needing lots of : dedicated functions (at the cost of performance). (The regex code is in : l3experimental.) For example, The following shoul (I hope) match a token : list made up entirely of letters with category code 'letter' : : \regex_match:nnTF { <tokens> } { ^\c[a-zA-Z]L+$ } ... Thanks. For token lists, the regex module seems more appropriate than my proposal. Also I have to admit that I hadn't looked at the regexp module yet. It certainly lets me do what I need. However, I think the functions I proposed are useful on their own. Regards, Marc