func _indicesOfRange()

in Sources/SE0270_RangeSet/RangeSet.swift [110:132]

• 11 lines of code
• 1 McCabe index (conditional complexity)

  func _indicesOfRange(_ range: Range<Bound>) -> Range<Int> {
    precondition(!range.isEmpty)
    precondition(!_ranges.isEmpty)
    precondition(range.lowerBound <= _ranges.last!.upperBound)
    precondition(range.upperBound >= _ranges.first!.lowerBound)
    
    // The beginning index for the position of `range` is the first range
    // with an upper bound larger than `range`'s lower bound. The range
    // at this position may or may not overlap `range`.
    let beginningIndex = _ranges
      ._partitioningIndex { $0.upperBound >= range.lowerBound }
    
    // The ending index for `range` is the first range with a lower bound
    // greater than `range`'s upper bound. If this is the same as
    // `beginningIndex`, than `range` doesn't overlap any of the existing
    // ranges. If this is `ranges.endIndex`, then `range` overlaps the
    // rest of the ranges. Otherwise, `range` overlaps one or
    // more ranges in the set.
    let endingIndex = _ranges[beginningIndex...]
      ._partitioningIndex { $0.lowerBound > range.upperBound }
    
    return beginningIndex ..< endingIndex
  }