Delete tree

19.0.0 released Nov 08, 2023

Delete tree

Purpose: Delete a node from a tree.

delete-tree <tree> key <key> \
    [ status [ define ] <status> ] \
    [ value [ define ] <value> ] \
    [ old-key [ define ] <old key> ]

delete-tree will search for <key> and if found, delete its node and set optional <status> (in "status" clause) to VV_OKAY. If <key> is not found, <status> will be VV_ERR_EXIST.

The key of the deleted node can be obtained in optional "old-key" clause in <old key> string; while its value in <value> in optional "value" clause, which can be a pointer of any type. Even though the value of <old key> will match <key> when deletion is successful, the two pointers may differ. Thus you may want to obtain <old key> if you need to release memory for the key, though in many cases you don't need to (see memory-handling). If <status> is not VV_OKAY, <value> and <old key> are unchanged.

Note that <status>, <value> and <old key> can be created with optional "define".

Examples

Delete node with key "123", and obtain its value and (the original) key.

char *k = "123";
delete-tree mytree key k value define val old-key define old_k status define st
if (st != VV_OKAY){
   @Could not find key <<p-out k>>
   exit-request
}
// delete the original key and value
delete-mem old_k
delete-mem val
@Deleted key <<p-out k>> with value <<p-out val>>