O(1) append — returns the node for future reference.

O(1) — mark the current end of the list so we can later discard everything appended after it. Used by speculative formatting: create a backup point, try an expression, and RollbackTo if it doesn't fit.

Collect the text content of the current (last) line by walking backward from the tail to the nearest newline event. Returns the concatenated Write texts in forward order.

O(1) insert after a given node — returns the new node.

O(1) insert before a given node — returns the new node.

O(1) remove a node from the list.

O(1) — discard every node appended after `point`, restoring the list to where it was when CreateBackupPoint was called. Pass null to clear the entire list (when the backup point was created on an empty list).

Iterate events from tail to head (reverse order).

Iterate events from head to tail.