On 5/18/15, Keith Medcalf <kmedcalf at dessus.com> wrote: > > Is there any reason why the default REGEXP is unsuitable? > > ext/misc/regexp.c > > in the source distribution ... >
Just in case it helps to answer the above question.... The RE syntax recognized by regexp.c is summarized in the header comment which can be perused here: https://www.sqlite.org/src/artifact/af92cdaa5058fcec The RE syntax recognized by regexp.c is a subset of PCRE. (The languages recognized by PCRE actually go beyond true Regular Expressions - but that is a topic for purists and theoreticians.) On the other hand, the regexp.c matcher is guaranteed to run in constant time (relative to the size of the string being scanned) whereas PCREs can run in exponential time for certain pathological cases. -- D. Richard Hipp drh at sqlite.org
