Re: [rules-dev] Prolog Style Backward Chaining - First Cut

Initial things to do: -Patterns should also work with positionals, based on @Position annotation -Expressions for query arguments should allow previous rule/global bindings and execute an "mvel return value" to resolve them prior to being passed to the query -Figure out good way for queries to approximate prolog behaviour of rules with same name where it unions the results. -Queries should allow field constriants, ==, >= etc. The behaviour for this is a unbound output variable on the field, which is filtered against the expression. -Allow bindings to the query itself and use a special implemention of the MVEL's PropertyHandler to allow bean like access to it. So declarations are like fields. -More extensive testing to find out what is not working or broken, that normal works in prolog like systems. -Allow ? to differentiate between push and pull data sources. ? can be used on a normal pattern to indicate it's a one off pull (query). ? When not added to a query indicates that the query should be left "open" to receive more data over time. -Support open queries, this is where the query window is left open and new data is propagated as a result.