sbtourist/Journal.IO — Issue #5: Reverse journal iteration (undo counterpart to redo)
Author: chrisvest
Created: 2012-02-03 08:38:49+00:00
State: open

The `redo()` method creates an iterator that traverses the journal in the order the records have been written. It would be nice to be able to traverse the journal in the _reverse_ order, from the most recently written record back to the oldest. This operation could be called `undo()`, though it sounds destructive it matches the `redo()` method.

One way I imagine this could be implemented, is to add a back-pointer to the Location details, that points to the preceding location in the data-file. Perhaps negative values can be used to indicate that the pointer refers to the preceding data-file as well. I have not checked if data-files know the location of their last record.