On Tuesday, August 8, 2017 at 11:38:34 AM UTC-5, Larry.... at gmail.com wrote: > Anyone have any code or know of any packages for validating a regexp? >> I have an app that allows users to enter regexps for db searching. > When a user enters an invalid one (e.g. 'A|B|' is one I just saw) it > causes downstream issues. I'd like to flag it at entry time. Hello, IIRC, there is a built-in regexp builder/tester in Boa Constructor: http://boa-constructor.sourceforge.net/ I used this a long time ago. Duane