span buffer test now passes. Code ist still too complicated.

common/spans.go

@@ -118,67 +118,31 @@ func (sp *SpanPool) Insert(s *Span, pos, value int32) *Span {
 			return head
 
 		case pos > s.To: // after span
+			next := s.Next
 			if pos == s.To+1 && value == s.Value { // directly neighbored
 				s.To = pos
 				// Check if a gap has to be closed
-				next := s.Next
-				if next != nil {
-					if next.From == s.To-1 && value == next.Value {
-						s.To = next.To
-						s.Next = next.Next
-						sp.Free(next)
-						return head
-					}
-					// Extend next?
-					if pos == next.From-1 && value == next.Value {
-						next.From = pos
-						return head
-					}
-					// Before next -> New between current and next
-					if pos < next.From {
-						sn := sp.Alloc()
-						sn.From = pos
-						sn.To = pos
-						sn.Value = value
-						sn.Next = next
-						s.Next = sn
-						return head
-					}
-				} else { // No next -> new at tail
-					sn := sp.Alloc()
-					sn.From = pos
-					sn.To = pos
-					sn.Value = value
-					sn.Next = nil
-					s.Next = sn
-					return head
-				}
-			} else { // Not directly connected and/or values do not match.
-				next := s.Next
-				if next != nil {
-					if pos == next.From-1 && value == next.Value {
-						next.From = pos
-						return head
-					}
-					// Before next -> New between current and next
-					if pos < next.From {
-						sn := sp.Alloc()
-						sn.From = pos
-						sn.To = pos
-						sn.Value = value
-						sn.Next = next
-						s.Next = sn
-						return head
-					}
-				} else { // No next -> new at tail
-					sn := sp.Alloc()
-					sn.From = pos
-					sn.To = pos
-					sn.Value = value
-					sn.Next = nil
-					s.Next = sn
-					return head
+				if next != nil && next.From == s.To+1 && value == next.Value {
+					s.To = next.To
+					s.Next = next.Next
+					sp.Free(next)
 				}
+				return head
+			}
+			// Extend next?
+			if next != nil && pos == next.From-1 && value == next.Value {
+				next.From = pos
+				return head
+			}
+			// Before next -> New between current and next
+			if next == nil || pos < next.From {
+				sn := sp.Alloc()
+				sn.From = pos
+				sn.To = pos
+				sn.Value = value
+				sn.Next = next
+				s.Next = sn
+				return head
 			}
 
 		default: // pos in span -> do not modify.