C pointer type representing file system history objects. A history object represents some event when a file system node is modified or copied, which doesn’t necessarily mean that the node’s contents or properties change with every history event.
Checks whether the given obj is a file system history object.
Retrieves a history object for the node at path below root.
Retrieves the next elder history object preceding history. If cross-copies? is not #f, the history chain is followed across copy events.
When is called for the first time on a return value of , it may return an object equivalent to the one that was passed in, in case that object itself represents an interesting history event.
Retrieves the revision number and the path of the given history event.