[DAS2] 'OR' syntax in query language

[Andrew Dalke]

We talked a bit about the DAS query language.

It is currently of the form (modulo URL escaping)

   name=Andrew,Roy;inside=Chr/100:200

This is the same as

(    name contains the substring "Andrew"
   OR name contains the substring "Roy"
) AND (
      feature is inside 100:200 on the segment named 'Chr'
)

That is, there is an AND of all terms, and a single term
may have multiple OR-ed subqueries, merged by commas.

We want to change this to the form

   name=Andrew;name=Roy;inside

That is, the query key can exist more than once.  Queries
with the same key are 'OR'ed, elsewise they are 'AND'ed.


The advantage is the simplicity of not having to worry
about another quoting rule, in this case how to search
for terms containing a ",".

The only disadvantage is with servers which don't handle
multiple keys in a query - but we think those client
libraries are long since deceased.

					Andrew
					dalke at dalkescientific.com