1 files changed, 51 insertions, 0 deletions

diff --git a/src/treeutil.h b/src/treeutil.h
new file mode 100644
index 0000000..76627c0
--- /dev/null
+++ b/src/treeutil.h
@@ -0,0 +1,51 @@
+// aux display and verification routines, helpful but not essential
+struct trunk {
+        struct trunk *prev;
+        const char *  str;
+};
+
+static void
+show_trunks(struct trunk *p)
+{
+        if ( !p )
+                return;
+        show_trunks(p->prev);
+        printf("%s", p->str);
+}
+
+// this is very haphazzard
+static void
+show_tree(struct tree_node *root, struct trunk *prev, int is_left)
+{
+        if ( root == NULL )
+                return;
+
+        struct trunk this_disp = { prev, "    " };
+        const char * prev_str  = this_disp.str;
+        show_tree(root->right, &this_disp, 1);
+
+        if ( !prev )
+                this_disp.str = "---";
+        else if ( is_left ) {
+                this_disp.str = ".--";
+                prev_str      = "   |";
+        }
+        else {
+                this_disp.str = "`--";
+                prev->str     = prev_str;
+        }
+
+        show_trunks(&this_disp);
+        if ( root->key >= 'A' && root->key <= 'Z' )
+                printf("%c\n", root->key);
+        else
+                printf("%d\n", root->key);
+
+        if ( prev )
+                prev->str = prev_str;
+        this_disp.str = "   |";
+
+        show_tree(root->left, &this_disp, 0);
+        if ( !prev )
+                puts("");
+}