Added inclusive / exclusive functionality

.gitignore

@@ -4,4 +4,4 @@
 
 debug.test
 example/debug
-example/out.png
+example/*.png

example/data.txt

@@ -6,4 +6,5 @@
 20,30
 25,28
 30,32
+0,1
 10,12

example/main.go

@@ -21,6 +21,26 @@ const (
 	MaxX = 40
 )
 
+type PlotType int
+
+const (
+	PlotTypeIntervals PlotType = iota
+	PlotTypeGaps
+	PlotTypeOverlapped
+	PlotTypeMerged
+)
+
+var (
+	openBracket      = "["
+	closeBracket     = "]"
+	openParenthesis  = "("
+	closeParenthesis = ")"
+	intervalOpening  = openBracket
+	intervalClosing  = closeBracket
+	lowInclusive     bool
+	highInclusive    bool
+)
+
 func main() {
 	filename := "data.txt"
 	xys, err := readData(filename)
@@ -47,12 +67,17 @@ func readData(path string) ([]xy, error) {
 	// read line by line using a scanner (because we don't know if the file will be huge)
 	s := bufio.NewScanner(f)
 	for s.Scan() {
-		var x, y int
+		var low, high int
-		_, err := fmt.Sscanf(s.Text(), "%d,%d", &x, &y)
+		_, err := fmt.Sscanf(s.Text(), "%d,%d", &low, &high)
 		if err != nil {
 			log.Printf("discarding bad data point %v: %v", s.Text(), err)
+			continue
 		}
-		xys = append(xys, xy{x, y})
+		if low > high {
+			log.Printf("discarding bad data point (low, high)=(%v): low can not be greater than high", s.Text())
+			continue
+		}
+		xys = append(xys, xy{low, high})
 	}
 	if err := s.Err(); err != nil {
 		return nil, fmt.Errorf("could not scan: %v", err)
@@ -61,7 +86,24 @@ func readData(path string) ([]xy, error) {
 }
 
 func initIntervals(xys []xy) interval.Intervals {
-	intervals := interval.NewIntervals(MinX, MaxX)
+	intervals := interval.NewIntervals(MinX, MaxX, true, true)
+
+	if intervals.IsLowInclusive() {
+		intervalOpening = "["
+		lowInclusive = true
+	} else {
+		intervalOpening = "("
+		lowInclusive = false
+	}
+
+	if intervals.IsHighInclusive() {
+		intervalClosing = "]"
+		highInclusive = true
+	} else {
+		intervalClosing = ")"
+		highInclusive = false
+	}
+
 	for _, xy := range xys {
 		intervals.Add(&interval.Interval{Low: xy.x, High: xy.y})
 	}
@@ -93,7 +135,7 @@ func alignPlots(plotItems []*plot.Plot) *vgimg.Canvas {
 		}
 	}
 
-	img := vgimg.New(vg.Points(512), vg.Points(float64(128*rows)))
+	img := vgimg.New(vg.Points(512), vg.Points(float64(200*rows)))
 	dc := draw.New(img)
 
 	t := draw.Tiles{
@@ -129,7 +171,7 @@ func createFileFromCanvas(path string, img *vgimg.Canvas) error {
 	return nil
 }
 
-func createPlot(title string, xys plotter.XYs) (*plot.Plot, error) {
+func createPlot(title string, xys plotter.XYs, plotType PlotType) (*plot.Plot, error) {
 	p, err := plot.New()
 	if err != nil {
 		return nil, fmt.Errorf("could not create plot: %v", err)
@@ -142,7 +184,7 @@ func createPlot(title string, xys plotter.XYs) (*plot.Plot, error) {
 	// p.X.Label.Text = "values"
 	p.X.Padding = vg.Length(5)
 	p.Y.Padding = vg.Length(20)
-	plotIntervals(p, xys)
+	plotIntervals(p, plotType, xys)
 	return p, nil
 }
 
@@ -151,7 +193,7 @@ func plotData(path string, intervals interval.Intervals) error {
 
 	// create Intervals plot
 	xysIntervals := convertToPlotterXYs(intervals.Get())
-	p1, err := createPlot("Intervals", xysIntervals)
+	p1, err := createPlot("Intervals", xysIntervals, PlotTypeIntervals)
 	if err != nil {
 		return fmt.Errorf("could not create plot: %v", err)
 	}
@@ -159,7 +201,7 @@ func plotData(path string, intervals interval.Intervals) error {
 
 	// create Gaps plot
 	xysGaps := convertToPlotterXYs(intervals.Gaps())
-	p2, err := createPlot("Gaps", xysGaps)
+	p2, err := createPlot("Gaps", xysGaps, PlotTypeGaps)
 	if err != nil {
 		return fmt.Errorf("could not create plot: %v", err)
 	}
@@ -167,7 +209,7 @@ func plotData(path string, intervals interval.Intervals) error {
 
 	// create Overlapped `plot
 	xysOverlapped := convertToPlotterXYs(intervals.Overlapped())
-	p3, err := createPlot("Overlapped", xysOverlapped)
+	p3, err := createPlot("Overlapped", xysOverlapped, PlotTypeOverlapped)
 	if err != nil {
 		return fmt.Errorf("could not create plot: %v", err)
 	}
@@ -175,7 +217,7 @@ func plotData(path string, intervals interval.Intervals) error {
 
 	// create Merged plot
 	xysMerged := convertToPlotterXYs(intervals.Merge())
-	p4, err := createPlot("Merged", xysMerged)
+	p4, err := createPlot("Merged", xysMerged, PlotTypeMerged)
 	if err != nil {
 		return fmt.Errorf("could not create plot: %v", err)
 	}
@@ -190,16 +232,71 @@ func plotData(path string, intervals interval.Intervals) error {
 	return nil
 }
 
-func plotIntervals(p *plot.Plot, xys plotter.XYs) error {
+func plotIntervals(p *plot.Plot, plotType PlotType, xys plotter.XYs) error {
 	var ps []plot.Plotter
 	colors := getColors()
 	numColors := len(colors)
+
+	crossShape := draw.CrossGlyph{}
+	ringShape := draw.RingGlyph{}
+	legendWithCrossShape := false
+	legendWithRingShape := false
 	for i, xy := range xys {
-		label := fmt.Sprintf("(%v,%v)", xy.X, xy.Y)
+		pXYLow := struct{ X, Y float64 }{xy.X, float64(i)}
-		pXYs := plotter.XYs{{xy.X, float64(i)}, {xy.Y, float64(i)}}
+		pXYHigh := struct{ X, Y float64 }{xy.Y, float64(i)}
+		pXYs := plotter.XYs{pXYLow, pXYHigh}
 		color := colors[i%numColors]
 
-		s, err := plotter.NewScatter(pXYs)
+		var s1, s2 *plotter.Scatter
+		var err error
+		label := ""
+		if plotType == PlotTypeIntervals {
+			label = fmt.Sprintf("%s%v,%v%s", intervalOpening, xy.X, xy.Y, intervalClosing)
+			s1, err = plotter.NewScatter(plotter.XYs{pXYLow})
+			if err != nil {
+				return fmt.Errorf("unable to create new scatter: %v", err)
+			}
+			if !lowInclusive {
+				s1.GlyphStyle.Shape = crossShape
+				if !legendWithCrossShape {
+					p.Legend.Add("Exclusive", s1)
+					legendWithCrossShape = true
+				}
+			} else {
+				s1.GlyphStyle.Shape = ringShape
+				if !legendWithRingShape {
+					p.Legend.Add("Inclusive", s1)
+					legendWithRingShape = true
+				}
+			}
+
+			s2, err = plotter.NewScatter(plotter.XYs{pXYHigh})
+			if err != nil {
+				return fmt.Errorf("unable to create new scatter: %v", err)
+			}
+			if !highInclusive {
+				s2.GlyphStyle.Shape = crossShape
+				if !legendWithCrossShape {
+					p.Legend.Add("Exclusive", s2)
+					legendWithCrossShape = true
+				}
+			} else {
+				s2.GlyphStyle.Shape = ringShape
+				if !legendWithRingShape {
+					p.Legend.Add("Inclusive", s2)
+					legendWithRingShape = true
+				}
+			}
+		} else {
+			label = fmt.Sprintf("%s%v,%v%s", openBracket, xy.X, xy.Y, closeBracket)
+			s1, err = plotter.NewScatter(pXYs)
+			if err != nil {
+				return fmt.Errorf("unable to create new scatter: %v", err)
+			}
+			if !lowInclusive && !highInclusive {
+				s1.GlyphStyle.Shape = crossShape
+			}
+		}
 
 		if xy.X != xy.Y {
 			l, err := plotter.NewLine(pXYs)
@@ -211,15 +308,20 @@ func plotIntervals(p *plot.Plot, xys plotter.XYs) error {
 			ps = append(ps, l)
 			p.Legend.Add(label, l)
 		} else {
-			s.Color = color
+			s1.Color = color
-			p.Legend.Add(label, s)
+			if s2 != nil {
+				s2.Color = color
+			}
+			p.Legend.Add(label, s1)
 		}
 
 		if err != nil {
 			return fmt.Errorf("could not create a new scatter: %v", err)
 		}
-		ps = append(ps, s)
+		ps = append(ps, s1)
-
+		if s2 != nil {
+			ps = append(ps, s2)
+		}
 	}
 	p.Legend.Left = false
 	p.Add(ps...)

find.go

@@ -1,14 +1,20 @@
 package interval
 
 func (intvls *intervals) FindIntervalsForValue(value int) []*Interval {
+	// sort intervals (if necessary)
 	intvls.Sort()
+
 	var matches []*Interval
 	for _, intvl := range intvls.Intervals {
-		if intvl.Low > value {
+		// convert if necessary exclusive low/high values into inclusive ones
-			// due to the intervals are sorted, we can confirm that we will not find more matches
+		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+
+		// check if we have to stop searching
+		if low > value {
+			// due to the intervals are sorted byLow, we can confirm that we will not find more matches
 			break
 		}
-		if inBetweenInclusive(value, intvl.Low, intvl.High) {
+		if inBetweenInclusive(value, low, high) {
 			matches = append(matches, intvl)
 		}
 	}

gaps.go

@@ -16,19 +16,33 @@ func (intvls *intervals) Gaps() []*Interval {
 }
 
 func (intvls *intervals) calculateGaps() []*Interval {
+	list := []*Interval{}
+	if len(intvls.Intervals) == 0 {
+		return list
+	}
+
+	// sort intervals (if necessary)
 	intvls.Sort()
-	gaps := []*Interval{}
+
-	lastMaxHigh := intvls.MinLow
+	gapThreshold := intvls.MinLow
 	for _, intvl := range intvls.Intervals {
-		if intvl.Low > lastMaxHigh {
+		// convert if necessary exclusive low/high values into inclusive ones
-			gaps = append(gaps, &Interval{Low: lastMaxHigh, High: intvl.Low - 1})
+		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+
+		// if the current Low is higher than the last maximal High, means that there is a gap so we add this gap to the list
+		if low > gapThreshold {
+			list = append(list, &Interval{Low: gapThreshold, High: low - 1})
 		}
-		if intvl.High >= lastMaxHigh {
+
-			lastMaxHigh = intvl.High + 1
+		// update if necessary the threshold for the next gap
+		if high >= gapThreshold {
+			gapThreshold = high + 1
 		}
 	}
-	if lastMaxHigh < intvls.MaxHigh {
+
-		gaps = append(gaps, &Interval{Low: lastMaxHigh, High: intvls.MaxHigh})
+	// if intvls.Intervals haven't covered all the range until the end, we need to fill the rest until the end as a gap
+	if gapThreshold < intvls.MaxHigh {
+		list = append(list, &Interval{Low: gapThreshold, High: intvls.MaxHigh})
 	}
-	return gaps
+	return list
 }

get.go

@@ -1,6 +1,9 @@
 package interval
 
 func (intvls *intervals) Get() []*Interval {
+	// sort intervals (if necessary)
 	intvls.Sort()
+
+	// return the intervals sorted
 	return intvls.Intervals
 }

inclusives.go

@@ -0,0 +1,37 @@
+package interval
+
+func (intvls *intervals) getInclusives(intervalLow, intervalHigh int) (int, int) {
+	low := intvls.getInclusiveLow(intervalLow)
+	high := intvls.getInclusiveHigh(intervalHigh)
+	if high < low {
+		high = low
+	}
+	if low > high {
+		low = high
+	}
+	return low, high
+}
+
+func (intvls *intervals) getInclusiveLow(value int) int {
+	if intvls.LowInclusive {
+		return value
+	}
+	// here the low is exclusive, we have to take the next value
+	newLow := value + 1
+	if newLow > intvls.MaxHigh {
+		return intvls.MaxHigh
+	}
+	return newLow
+}
+
+func (intvls *intervals) getInclusiveHigh(value int) int {
+	if intvls.HighInclusive {
+		return value
+	}
+	// here the high is exclusive, we have to take the previous value
+	newHigh := value - 1
+	if newHigh < intvls.MinLow {
+		return intvls.MinLow
+	}
+	return newHigh
+}

intervals.go

@@ -5,8 +5,10 @@ import (
 )
 
 const (
-	defaultMinLow  = 0
+	defaultMinLow        = 0
-	defaultMaxHigh = math.MaxInt64
+	defaultMaxHigh       = math.MaxInt64
+	defaultLowInclusive  = true
+	defaultHighInclusive = true
 )
 
 // Intervals is an interface to handle Interval structures discovering the existence of gaps or overlays
@@ -39,6 +41,12 @@ type Intervals interface {
 
 	// Report first sorts (if necessary) and then creates a report of the interval sequence
 	Report() string
+
+	// IsLowInclusive indicates if the Low part of the interval is included, e. g. (3,5) --> the 3 is included as part of the interval
+	IsLowInclusive() bool
+
+	// IsHighInclusive indicates if the High part of the interval is included, e. g. (3,5) --> the 5 is included as part of the interval
+	IsHighInclusive() bool
 }
 
 // intervals implements Intervals interface
@@ -50,19 +58,31 @@ type intervals struct {
 	MinLow         int
 	MaxHigh        int
 	Sorted         bool
+	LowInclusive   bool
+	HighInclusive  bool
 }
 
 // NewIntervalsDefault is a constructor that returns an instance of the Intervals interface with default values
 func NewIntervalsDefault() Intervals {
-	return NewIntervals(defaultMinLow, defaultMaxHigh)
+	return NewIntervals(defaultMinLow, defaultMaxHigh, defaultLowInclusive, defaultHighInclusive)
 }
 
 // NewIntervals is a constructor that returns an instance of the Intervals interface
-func NewIntervals(minLow int, maxHigh int) Intervals {
+func NewIntervals(minLow int, maxHigh int, lowInclusive bool, highInclusive bool) Intervals {
 	return &intervals{
-		MinLow:    minLow,
+		MinLow:        minLow,
-		MaxHigh:   maxHigh,
+		MaxHigh:       maxHigh,
-		Intervals: []*Interval{},
+		Intervals:     []*Interval{},
-		Sorted:    false,
+		Sorted:        false,
+		LowInclusive:  lowInclusive,
+		HighInclusive: highInclusive,
 	}
 }
+
+func (intvls *intervals) IsLowInclusive() bool {
+	return intvls.LowInclusive
+}
+
+func (intvls *intervals) IsHighInclusive() bool {
+	return intvls.HighInclusive
+}

merge.go

@@ -8,33 +8,66 @@ func (intvls *intervals) Merge() []*Interval {
 }
 
 func (intvls *intervals) calculateMerged() []*Interval {
-	intvls.Sort()
 	list := []*Interval{}
 	if len(intvls.Intervals) == 0 {
 		return list
 	}
 
-	var lastLow int
+	// sort intervals (if necessary)
-	var lastHigh int
+	intvls.Sort()
+
+	var currentMinLow int
+	var currentMaxHigh int
 	for i, intvl := range intvls.Intervals {
+		// convert if necessary exclusive low/high values into inclusive ones
+		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+
+		// in the first iteration it's for sure that don't exists merge, we just initialize variables
 		if i == 0 {
-			lastLow = intvl.Low
+			currentMinLow = low
-			lastHigh = intvl.High
+			currentMaxHigh = high
 			continue
 		}
-		if isLowInBetween(intvl.Low, intvl.High, lastLow, lastHigh) || isHighInBetween(intvl.Low, intvl.High, lastLow, lastHigh) {
+
-			if intvl.Low < lastLow {
+		// in case the current interval is overlapped or consecutive to the previous one, we need to update variables
-				lastLow = intvl.Low
+		// and keep going and process the next interval
+		if areSegmentsConsecutivesOrOverlapped(low, high, currentMinLow, currentMaxHigh) {
+			// update control variables if necessary
+			if low < currentMinLow {
+				currentMinLow = low
 			}
-			if intvl.High > lastHigh {
+			if high > currentMaxHigh {
-				lastHigh = intvl.High
+				currentMaxHigh = high
 			}
 			continue
 		}
-		list = append(list, &Interval{Low: lastLow, High: lastHigh})
+
-		lastLow = intvl.Low
+		// here the segments are not consecutive or overlapped so we close this merged segment (add to the list)
-		lastHigh = intvl.High
+		list = append(list, &Interval{Low: currentMinLow, High: currentMaxHigh})
+
+		// update control variables
+		currentMinLow = low
+		currentMaxHigh = high
 	}
-	list = append(list, &Interval{Low: lastLow, High: lastHigh})
+	// the last segment is pending to be added to the list
+	list = append(list, &Interval{Low: currentMinLow, High: currentMaxHigh})
 	return list
 }
+
+func areSegmentsOverlapped(low, high, lastLow, lastHigh int) bool {
+	if isLowInBetweenInclusive(low, high, lastLow, lastHigh) {
+		return true
+	}
+	if isHighInBetweenInclusive(low, high, lastLow, lastHigh) {
+		return true
+	}
+	return false
+}
+
+func areSegmentsConsecutives(low, high, lastLow, lastHigh int) bool {
+	return ((lastHigh + 1) == low) || ((high + 1) == lastLow)
+}
+
+func areSegmentsConsecutivesOrOverlapped(low, high, lastLow, lastHigh int) bool {
+	return areSegmentsOverlapped(low, high, lastLow, lastHigh) || areSegmentsConsecutives(low, high, lastLow, lastHigh)
+}

overlap.go

@@ -18,25 +18,38 @@ func (intvls *intervals) Overlapped() []*Interval {
 }
 
 func (intvls *intervals) calculateOverlapped() []*Interval {
-	intvls.Sort()
 	list := []*Interval{}
+	if len(intvls.Intervals) == 0 {
+		return list
+	}
+
+	// sort intervals (if necessary)
+	intvls.Sort()
+
 	lastMinLow := math.MaxInt64
 	lastMaxHigh := math.MinInt64
 	for i, intvl := range intvls.Intervals {
+		// convert if necessary exclusive low/high values into inclusive ones
+		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+
+		// for the first iteration make no sense those operations
 		if i > 0 {
-			lowInBetween := isLowInBetween(lastMinLow, lastMaxHigh, intvl.Low, intvl.High)
+			// check if the front or back side of the current segment overlaps with the previous one
-			highInBetween := isHighInBetween(lastMinLow, lastMaxHigh, intvl.Low, intvl.High)
+			lowInBetween := isLowInBetweenInclusive(lastMinLow, lastMaxHigh, low, high)
+			highInBetween := isHighInBetweenInclusive(lastMinLow, lastMaxHigh, low, high)
 			if lowInBetween || highInBetween {
-				greaterLow := max(intvl.Low, lastMinLow)
+				// extract which part is overlapped, create a new interval and add it to the list
-				lowerHigh := min(intvl.High, lastMaxHigh)
+				biggestLow := max(low, lastMinLow)
-				list = append(list, &Interval{Low: greaterLow, High: lowerHigh})
+				smallestHigh := min(high, lastMaxHigh)
+				list = append(list, &Interval{Low: biggestLow, High: smallestHigh})
 			}
 		}
-		if intvl.Low < lastMinLow {
+		// update control variables (if necessary)
-			lastMinLow = intvl.Low
+		if low < lastMinLow {
+			lastMinLow = low
 		}
-		if intvl.High > lastMaxHigh {
+		if high > lastMaxHigh {
-			lastMaxHigh = intvl.High
+			lastMaxHigh = high
 		}
 	}
 	return list
@@ -44,7 +57,7 @@ func (intvls *intervals) calculateOverlapped() []*Interval {
 
 func (intvls *intervals) valueIsOverlapping(value int, overlapped []*Interval) bool {
 	for _, ovrlp := range overlapped {
-		if inBetweenInclusive(value, ovrlp.Low, ovrlp.High) {
+		if inBetween(value, ovrlp.Low, ovrlp.High, intvls.LowInclusive, intvls.HighInclusive) {
 			return true
 		}
 	}

sort.go

@@ -3,6 +3,7 @@ package interval
 import "sort"
 
 func (intvls *intervals) Sort() {
+	// sort the intervals slice just if necessary
 	if !intvls.Sorted {
 		sort.Sort(ByLow(intvls.Intervals))
 	}

utils.go

@@ -13,6 +13,23 @@ func max(a, b int) int {
 	return b
 }
 
+func inBetween(i, min, max int, lowInclusive, highInclusive bool) bool {
+	if lowInclusive && highInclusive {
+		return inBetweenInclusive(i, min, max)
+	}
+	if !lowInclusive && !highInclusive {
+		return inBetweenExclusive(i, min, max)
+	}
+	if lowInclusive && !highInclusive {
+		return inBetweenLowInclusive(i, min, max)
+	}
+	if !lowInclusive && highInclusive {
+		return inBetweenHighInclusive(i, min, max)
+	}
+	return false
+}
+
+// both inclusive
 func inBetweenInclusive(i, min, max int) bool {
 	if (i >= min) && (i <= max) {
 		return true
@@ -20,6 +37,23 @@ func inBetweenInclusive(i, min, max int) bool {
 	return false
 }
 
+// only low is inclusive
+func inBetweenLowInclusive(i, min, max int) bool {
+	if (i >= min) && (i < max) {
+		return true
+	}
+	return false
+}
+
+// only high is inclusive
+func inBetweenHighInclusive(i, min, max int) bool {
+	if (i > min) && (i <= max) {
+		return true
+	}
+	return false
+}
+
+// both exclusive
 func inBetweenExclusive(i, min, max int) bool {
 	if (i > min) && (i < max) {
 		return true
@@ -27,14 +61,28 @@ func inBetweenExclusive(i, min, max int) bool {
 	return false
 }
 
-func isLowInBetween(low1, high1, low2, high2 int) bool {
+func isLowInBetween(low1, high1, low2, high2 int, lowInclusive, highInclusive bool) bool {
+	if inBetween(low1, low2, high2, lowInclusive, highInclusive) || inBetween(low2, low1, high1, lowInclusive, highInclusive) {
+		return true
+	}
+	return false
+}
+
+func isLowInBetweenInclusive(low1, high1, low2, high2 int) bool {
 	if inBetweenInclusive(low1, low2, high2) || inBetweenInclusive(low2, low1, high1) {
 		return true
 	}
 	return false
 }
 
-func isHighInBetween(low1, high1, low2, high2 int) bool {
+func isHighInBetween(low1, high1, low2, high2 int, lowInclusive, highInclusive bool) bool {
+	if inBetween(high1, low2, high2, lowInclusive, highInclusive) || inBetween(high2, low1, high1, lowInclusive, highInclusive) {
+		return true
+	}
+	return false
+}
+
+func isHighInBetweenInclusive(low1, high1, low2, high2 int) bool {
 	if inBetweenInclusive(high1, low2, high2) || inBetweenInclusive(high2, low1, high1) {
 		return true
 	}