Project's home: https://www.hexstreamsoft.com/libraries/parse-number-range/ parse-number-range parses LOOP's convenient "for-as-arithmetic" syntax into 5 simple values: from, to, limit-kind (:inclusive, :exclusive or nil if unbounded), by (step) and direction (+ or -)). Further related utilities are provided. Intended for easy implementation of analogous functionality in other constructs. This library is in the Public Domain. See the UNLICENSE file for details.