splited big file into smaller files by functionality

merge.go

@@ -0,0 +1,32 @@
+package interval
+
+func (intvls *intervals) Merge() []*Interval {
+	if intvls.MergeList == nil {
+		intvls.MergeList = intvls.calculateMerged()
+	}
+	return intvls.MergeList
+}
+
+func (intvls *intervals) calculateMerged() []*Interval {
+	intvls.Sort()
+	list := []*Interval{}
+	var lastLow int
+	var lastHigh int
+	for i, intvl := range intvls.Intervals {
+		if i == 0 {
+			lastLow = intvl.Low
+			lastHigh = intvl.High
+			continue
+		}
+		if inBetweenInclusive(intvl.Low, lastLow, lastHigh) {
+			// because the intervals are previously sorted, we just need to take care of the High value
+			if intvl.High > lastHigh {
+				lastHigh = intvl.High
+			}
+			continue
+		}
+		list = append(list, &Interval{Low: lastLow, High: lastHigh})
+	}
+	list = append(list, &Interval{Low: lastLow, High: lastHigh})
+	return list
+}