Feature Request

Summary

First thanks for all the hard work on this core library. It's been fantastic to have something like this to use.

I'm presently maintaining a symfony bundle that allows people to use either Doctrine ORM or ODM as their datastore, as well as other options (DtcQueueBundle). One of the requests has been if people don't use ORM, then the Doctrine Migrator shouldn't generate the tables for it See this issue.

This traces back to setFilterSchemaAssetsExpression which of course I could call in my compiler pass if ORM is not used, however it only allows a single filter at a time, so if someone sets a filter in their schema_filter symfony configuration, I can't add an additional filter on top of that to filter out the DtcQueueBundle tables without overwriting that filter.

I could write code to parse any existing filter's regular expression and then add additional regular criteria to the same original one, but that seems tricky and prone to error.

I'd rather just have the ability to "addFilterSchemaAssetsExpression" and the filter expressions be treated like an array.

Nevertheless if there's a better way to do this, I'm all ears.