The FEEL type range (DMN 1.6, section 10.3.2.7): an interval between two endpoints.

Ranges come from interval syntax such as [1..10), from prefix tests such as < 5 and >= x, and from the range built-in. A prefix test leaves one side undefined: < 5 has no start, and >= 5 has no end. An undefined endpoint is nil and its side is never included.

The type of a range is range<T>, where T is the type of its endpoints.

Fields

• :start and :end - the endpoints, or nil when undefined.
• :start_included and :end_included - whether each endpoint belongs to the range. These are the start included and end included properties.
• :operator - how the range was written: nil for an interval, [1..10), or the comparison of a prefix test, :lt, :lte, :gt, :gte, :eq or :neq, for (< 10) and the others (D-61). The properties are those of Table 42 either way, but the two are not equal: (< 10) = (null..10) is false, and so is (= 10) = [10..10] (TCK 0068#range_006, #range_010), as the specification has it, "the same endpoints and the same comparison operator or inclusivity flag" (notes 02, A-07). (!= 10) has the endpoint on both sides, left out of the range, and a value is in it when it is not equal to the endpoint: that is a decision (D-61). The TCK had the properties of (!=10) in 0074#range_012 and has commented the case out (dmn-tck/tck PR 671), so nothing asserts them; only (!=10) = (!=10) is (0068#range_012).

The struct does not check that the endpoints are of one kind or in order; building a range from arbitrary values is the evaluator's job, and it decides when that yields null.