Backend update Jun 20th 2018
select() function and => pair operator for conditional evaluation, e.g. select(value == "string" => "match", "default") yielding "match" if value == "string", otherwise "default".... splat operator which pulls array and object members into the current scope, e.g. [...[1,2], 3, ...[4,5]] yielding [1,2,3,4,5], and similarly {...{"a":1,"b":2}, "c":3, ...{"d":4,"e":5}} yielding {"a":1,"b":2,"c":3,"d":4,"e":5}.*{_id, value == "string" => {"foo": "bar"}} yields {_id, "foo": "bar"} if value == "string" evaluates to true. This is exactly equivalent to *{_id, ...select(value == "string" => {"foo": "bar"}}.match can now use * wildcards anywhere in the search term, not only at the end, e.g. *[ value match "a*c" ].&& terms), which in particular improved performance significantly for anonymous users.count() no longer gives error on null arguments.