Added control to prevent invalid low/high ranges

example/main.go

@@ -30,6 +30,11 @@ const (
 	PlotTypeMerged
 )
 
+type Superplot struct {
+	Plot        *plot.Plot
+	NumElements int
+}
+
 var (
 	openBracket      = "["
 	closeBracket     = "]"
@@ -119,7 +124,7 @@ func convertToPlotterXYs(intervals []*interval.Interval) plotter.XYs {
 	return pxys
 }
 
-func alignPlots(plotItems []*plot.Plot) *vgimg.Canvas {
+func alignPlots(plotItems []*Superplot) *vgimg.Canvas {
 	rows, cols := len(plotItems), 1
 	plots := make([][]*plot.Plot, rows)
 	for j := 0; j < rows; j++ {
@@ -128,10 +133,10 @@ func alignPlots(plotItems []*plot.Plot) *vgimg.Canvas {
 			p := plotItems[j]
 
 			// make sure the horizontal scales match
-			p.X.Min = MinX
-			p.X.Max = MaxX
+			p.Plot.X.Min = MinX
+			p.Plot.X.Max = MaxX
 
-			plots[j][i] = p
+			plots[j][i] = p.Plot
 		}
 	}
 
@@ -171,7 +176,7 @@ func createFileFromCanvas(path string, img *vgimg.Canvas) error {
 	return nil
 }
 
-func createPlot(title string, xys plotter.XYs, plotType PlotType) (*plot.Plot, error) {
+func createPlot(title string, xys plotter.XYs, plotType PlotType) (*Superplot, error) {
 	p, err := plot.New()
 	if err != nil {
 		return nil, fmt.Errorf("could not create plot: %v", err)
@@ -181,15 +186,15 @@ func createPlot(title string, xys plotter.XYs, plotType PlotType) (*plot.Plot, e
 	p.Add(plotter.NewGrid())
 	p.Title.Text = title
 	p.HideY()
-	// p.X.Label.Text = "values"
 	p.X.Padding = vg.Length(5)
 	p.Y.Padding = vg.Length(20)
+
 	plotIntervals(p, plotType, xys)
-	return p, nil
+	return &Superplot{p, xys.Len()}, nil
 }
 
 func plotData(path string, intervals interval.Intervals) error {
-	plots := []*plot.Plot{}
+	plots := []*Superplot{}
 
 	// create Intervals plot
 	xysIntervals := convertToPlotterXYs(intervals.Get())

find.go

@@ -1,5 +1,7 @@
 package interval
 
+import "fmt"
+
 func (intvls *intervals) FindIntervalsForValue(value int) []*Interval {
 	// sort intervals (if necessary)
 	intvls.Sort()
@@ -7,7 +9,11 @@ func (intvls *intervals) FindIntervalsForValue(value int) []*Interval {
 	var matches []*Interval
 	for _, intvl := range intvls.Intervals {
 		// convert if necessary exclusive low/high values into inclusive ones
-		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+		low, high, err := intvls.getInclusives(intvl.Low, intvl.High)
+		if err != nil {
+			fmt.Printf("FindIntervalsForValue - unable to get inclusives: %v", err)
+			continue
+		}
 
 		// check if we have to stop searching
 		if low > value {

gaps.go

@@ -1,5 +1,7 @@
 package interval
 
+import "fmt"
+
 func (intvls *intervals) HasGaps() bool {
 	intvls.Gaps()
 	if intvls.GapsList != nil && len(intvls.GapsList) > 0 {
@@ -27,7 +29,11 @@ func (intvls *intervals) calculateGaps() []*Interval {
 	gapThreshold := intvls.MinLow
 	for _, intvl := range intvls.Intervals {
 		// convert if necessary exclusive low/high values into inclusive ones
-		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+		low, high, err := intvls.getInclusives(intvl.Low, intvl.High)
+		if err != nil {
+			fmt.Printf("calculateGaps - unable to get inclusives: %v", err)
+			continue
+		}
 
 		// 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 {

inclusives.go

@@ -1,15 +1,22 @@
 package interval
 
-func (intvls *intervals) getInclusives(intervalLow, intervalHigh int) (int, int) {
+import (
+	"fmt"
+)
+
+func (intvls *intervals) getInclusives(intervalLow, intervalHigh int) (int, int, error) {
 	low := intvls.getInclusiveLow(intervalLow)
 	high := intvls.getInclusiveHigh(intervalHigh)
-	if high < low {
-		high = low
-	}
+
+	// if we get an incoherent result it's because it's invalid, for example in this case:
+	//		(low,high)=(0,1) --> if we add 1 to the Low and substract 1 to the High ends with (1,0) which is not valid
 	if low > high {
-		low = high
+		return 0, 0, fmt.Errorf("low (%v) can not be bigger than high (%v)", low, high)
 	}
-	return low, high
+	if high < low {
+		return 0, 0, fmt.Errorf("high (%v) can not be smaller than low (%v)", high, low)
+	}
+	return low, high, nil
 }
 
 func (intvls *intervals) getInclusiveLow(value int) int {

merge.go

@@ -1,5 +1,7 @@
 package interval
 
+import "github.com/labstack/gommon/log"
+
 func (intvls *intervals) Merge() []*Interval {
 	if intvls.MergeList == nil {
 		intvls.MergeList = intvls.calculateMerged()
@@ -18,14 +20,20 @@ func (intvls *intervals) calculateMerged() []*Interval {
 
 	var currentMinLow int
 	var currentMaxHigh int
-	for i, intvl := range intvls.Intervals {
+	firstInitDone := false
+	for _, intvl := range intvls.Intervals {
 		// convert if necessary exclusive low/high values into inclusive ones
-		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+		low, high, err := intvls.getInclusives(intvl.Low, intvl.High)
+		if err != nil {
+			log.Errorf("calculateMerged - unable to get inclusives: %v", err)
+			continue
+		}
 
 		// in the first iteration it's for sure that don't exists merge, we just initialize variables
-		if i == 0 {
+		if !firstInitDone {
 			currentMinLow = low
 			currentMaxHigh = high
+			firstInitDone = true
 			continue
 		}
 

overlap.go

@@ -1,6 +1,9 @@
 package interval
 
-import "math"
+import (
+	"fmt"
+	"math"
+)
 
 func (intvls *intervals) HasOverlapped() bool {
 	intvls.Overlapped()
@@ -28,12 +31,17 @@ func (intvls *intervals) calculateOverlapped() []*Interval {
 
 	lastMinLow := math.MaxInt64
 	lastMaxHigh := math.MinInt64
-	for i, intvl := range intvls.Intervals {
+	firstInitDone := false
+	for _, intvl := range intvls.Intervals {
 		// convert if necessary exclusive low/high values into inclusive ones
-		low, high := intvls.getInclusives(intvl.Low, intvl.High)
+		low, high, err := intvls.getInclusives(intvl.Low, intvl.High)
+		if err != nil {
+			fmt.Printf("calculateOverlapped - unable to get inclusives: %v", err)
+			continue
+		}
 
 		// for the first iteration make no sense those operations
-		if i > 0 {
+		if firstInitDone {
 			// check if the front or back side of the current segment overlaps with the previous one
 			lowInBetween := isLowInBetweenInclusive(lastMinLow, lastMaxHigh, low, high)
 			highInBetween := isHighInBetweenInclusive(lastMinLow, lastMaxHigh, low, high)
@@ -51,6 +59,7 @@ func (intvls *intervals) calculateOverlapped() []*Interval {
 		if high > lastMaxHigh {
 			lastMaxHigh = high
 		}
+		firstInitDone = true
 	}
 	return list
 }