Add split function for ropes

Ropes should be rebalanced at the end of this function once
rope_rebalance() is implemented.

1 files changed, 65 insertions, 0 deletions

diff --git a/structures/rope/rope.c b/structures/rope/rope.c
index 1f0a389..6e79b24 100644
--- a/structures/rope/rope.c
+++ b/structures/rope/rope.c
@@ -131,3 +131,68 @@ rope *node1, *node2;
 
 	return tmp;
 }
+
+rope* rope_split(root, i)
+rope **root;
+size_t i;
+{
+	rope **tmp, *split, *cur;
+
+	rope *orig = *root;
+
+	if (!root )
+		return NULL;
+
+	if (!i) {
+		split = *root;
+		*root = NULL;
+		return split;
+	}
+
+
+	tmp = root;
+			printf("i: %d\n", i);
+	while (!(*tmp)->str) {
+		if ((*tmp)->len <= i && (*tmp)->right) {
+			i -= (*tmp)->len;
+			printf("i: %d\n", i);
+			tmp = &(*tmp)->right;
+		} else if ((*tmp)->left) {
+			tmp = &(*tmp)->left;
+		}
+	}
+
+	if (i != 0) {
+		split = str_to_rope((*tmp)->str + i);
+		(*tmp)->str[i] = '\0';
+			/*Maybe want to strdup this and free to reduce memory usage*/
+
+		cur = (*tmp)->parent;
+		*tmp = rope_concat(*tmp, split);
+		(*tmp)->parent = cur;
+
+		split = (*tmp)->right;
+		(*tmp)->right = NULL;
+	} else {
+		split = *tmp;
+	}
+
+
+	for(cur = split; cur->parent; cur = cur->parent) {
+		if (cur->parent->right == cur)
+			continue;
+
+		split = rope_concat(split, cur->parent->right);
+		cur->parent->right = NULL;
+	}
+
+	if (cur && cur->right == split)
+		cur->right = NULL;
+	*root = cur;
+
+	/*TODO should be rebalancing rather than just recalulating lengths*/
+	rope_relen(split);
+	rope_relen(*root);
+
+	return split;
+}