Do not assume Compare returns -1 or +1 if not zero

b97tsk · Jan 22, 2024 · 953f38d · 953f38d
1 parent e2bee10
commit 953f38d
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Showing 2 changed files with 16 additions and 12 deletions.
diff --git a/difference.go b/difference.go
@@ -59,12 +59,14 @@ func difference[E Elem[E]](x, y, out Set[E]) Set[E] {
 			continue
 		}
 
-		switch lo := x[0].Low; lo.Compare(r.Low) {
-		case -1:
+		lo := x[0].Low
+
+		switch c := lo.Compare(r.Low); {
+		case c < 0:
 			if !inv {
 				z = append(z, Range(lo, r.Low))
 			}
-		case +1:
+		case c > 0:
 			if inv {
 				z = append(z, Range(r.Low, lo))
 			}
@@ -79,12 +81,12 @@ func difference[E Elem[E]](x, y, out Set[E]) Set[E] {
 		hi := x[j-1].High
 		x = x[j:]
 
-		switch hi.Compare(r.High) {
-		case -1:
+		switch c := hi.Compare(r.High); {
+		case c < 0:
 			if inv {
 				z = append(z, Range(hi, r.High))
 			}
-		case +1:
+		case c > 0:
 			r.Low, r.High = r.High, hi
 			x, y = y, x
 			inv = !inv

diff --git a/symdiff.go b/symdiff.go
@@ -46,10 +46,12 @@ func symmetricDifference[E Elem[E]](x, y, out Set[E]) Set[E] {
 			continue
 		}
 
-		switch lo := x[0].Low; lo.Compare(r.Low) {
-		case -1:
+		lo := x[0].Low
+
+		switch c := lo.Compare(r.Low); {
+		case c < 0:
 			z = appendInterval(z, Range(lo, r.Low))
-		case +1:
+		case c > 0:
 			z = appendInterval(z, Range(r.Low, lo))
 		}
 
@@ -60,10 +62,10 @@ func symmetricDifference[E Elem[E]](x, y, out Set[E]) Set[E] {
 		hi := x[j-1].High
 		x = x[j:]
 
-		switch hi.Compare(r.High) {
-		case -1:
+		switch c := hi.Compare(r.High); {
+		case c < 0:
 			z = append(z, Range(hi, r.High))
-		case +1:
+		case c > 0:
 			r.Low, r.High = r.High, hi
 			x, y = y, x