better rbtree diagnostics

1 files changed, 30 insertions, 0 deletions

diff --git a/pkg/rbtree/print_test.go b/pkg/rbtree/print_test.go
new file mode 100644
index 0000000..c4154c8
--- /dev/null
+++ b/pkg/rbtree/print_test.go
@@ -0,0 +1,30 @@
+package rbtree
+
+import (
+	"fmt"
+	"io"
+	"strings"
+)
+
+func (t *Tree[K, V]) ASCIIArt() string {
+	var out strings.Builder
+	t.root.asciiArt(&out, "", "", "")
+	return out.String()
+}
+
+func (node *Node[V]) asciiArt(w io.Writer, u, m, l string) {
+	if node == nil {
+		fmt.Fprintf(w, "%snil\n", m)
+		return
+	}
+
+	node.Right.asciiArt(w, u+"     ", u+"  ,--", u+"  |  ")
+
+	if node.Color == Red {
+		fmt.Fprintf(w, "%sR(%v)\n", m, node.Value)
+	} else {
+		fmt.Fprintf(w, "%sB(%v)\n", m, node.Value)
+	}
+
+	node.Left.asciiArt(w, l+"  |  ", l+"  `--", l+"     ")
+}