Universal Segment

The UniversalSegment domain generalizes Segment by allowing segments without a “hi” end point.

pints := 1..
  1..
                              Type: UniversalSegment PositiveInteger

nevens := (0..) by -2
  0.. by - 2
                              Type: UniversalSegment NonNegativeInteger

Values of type Segment are automatically converted to type UniversalSegment when appropriate.

useg: UniversalSegment(Integer) := 3..10
  3..10
                              Type: UniversalSegment Integer

The operation hasHi is used to test whether a segment has a hi end point.

hasHi pints
  false
                              Type: Boolean

hasHi nevens
  false
                              Type: Boolean

hasHi useg
  true
                              Type: Boolean

All operations available on type Segment apply to UniversalSegment, with the proviso that expansions produce streams rather than lists. This is to accommodate infinite expansions.

expand pints
  [1,2,3,4,5,6,7,8,9,10,...]
                              Type: Stream Integer

expand nevens
  [0,- 2,- 4,- 6,- 8,- 10,- 12,- 14,- 16,- 18,...]
                              Type: Stream Integer

expand [1, 3, 10..15, 100..]
  [1,3,10,11,12,13,14,15,100,101,...]
                              Type: Stream Integer

See Also:

• )help Segment
• )help SegmentBinding
• )help List
• )help Stream
• )show UniversalSegment