Basically it would be trivial to report far more operations
explicitly, but for the fact that the values in qc_query_op_t
currently, quite unnecessarily, form a bitmask.
In 2.2 that is no longer the case, so other operations will be
added there.
It is now possible to specify what information the caller is interested
in. With this the cost for collecting information during the query parsing
that nobody is interested in can be avoided.
For the general case, regex matching simply will not do. The
regex becomes so hairy so it turns write-only, i.e. unmaintainable.
Regex matching is also slower than a handwritten custom parser.