Transducers

compile-query returns a Clojure transducer for the query's filtering, derivation, :drop, :take, and projection stages. It can be used with reducible inputs without first building a date vector:

(transduce (q/compile-query query) conj []
           (q/reducible-date-range "2026-11-01" "2027-02-28"))

The same transducer can be passed to into, sequence, or eduction. It has no shared mutable state. calendar-windows is also a transducer; it emits consecutive vectors grouped by :date, :month, :quarter, :year, or :iso-week.

reducible-date-range is an inclusive IReduce/IReduceInit source. date-range is a lazy sequence alternative. This library does not claim that either source is faster; measure with the workload and JDK that matter to your application.