Adds a value to the collection. For !!map and !!omap the value must be a Pair instance or a { key, value } object, which may not have a key that already exists in the map.

Create a copy of this collection.

Removes a value from the collection.

Returns item at key, or undefined if not found. By default unwraps scalar values from their surrounding node; to disable set keepScalar to true (collections are always returned intact).

Checks if the collection includes a value with the key key.

Sets a value in this collection. For !!set, value needs to be a boolean to add/remove the item from the set.