VersionConstraint intersect()

in lib/src/version_union.dart [95:123]

• 19 lines of code
• 7 McCabe index (conditional complexity)

  VersionConstraint intersect(VersionConstraint other) {
    var ourRanges = ranges.iterator;
    var theirRanges = _rangesFor(other).iterator;

    // Because both lists of ranges are ordered by minimum version, we can
    // safely move through them linearly here.
    var newRanges = <VersionRange>[];
    var ourRangesMoved = ourRanges.moveNext();
    var theirRangesMoved = theirRanges.moveNext();
    while (ourRangesMoved && theirRangesMoved) {
      var intersection = ourRanges.current.intersect(theirRanges.current);

      if (!intersection.isEmpty) newRanges.add(intersection as VersionRange);

      // Move the constraint with the lower max value forward. This ensures that
      // we keep both lists in sync as much as possible, and that large ranges
      // have a chance to match multiple small ranges that they contain.
      if (allowsHigher(theirRanges.current, ourRanges.current)) {
        ourRangesMoved = ourRanges.moveNext();
      } else {
        theirRangesMoved = theirRanges.moveNext();
      }
    }

    if (newRanges.isEmpty) return VersionConstraint.empty;
    if (newRanges.length == 1) return newRanges.single;

    return VersionUnion.fromRanges(newRanges);
  }