undone

Version: 0.2

Three implementations

This module offers three undo stack implementations. Each has different tradeoffs, and may be better suited to a given situation than the others.

define a class (or named tuple) for each operation, with "do" and "undo" methods
hand instances of these classes to the stack object
doesn't require any handle on the object(s) being modified by the operations
up to the user to ensure reversibility, which in some cases can be quite difficult
least memory and runtime overhead for operations

define a callable object for each operation
hand instances of these objects to the stack object
requires a handle on or snapshot of the initial state of the object(s) being modified by the operations; operations must accept this handle as a parameter when called
higher overhead, especially for undo operation

requires handles on or snapshots of incremental states of the object(s) being modified. These snapshots are triggered explicitly by the user, and may be taken as frequently or rarely as desired
can involve significant memory overhead in the worst case

undone works under Python 2.7 and Python 3.3+.

To install:

$ git clone http://github.com/gfetterman/undone.git
$ cd undone
$ pip install .

# to run the tests
$ pytest -v

(Coming soon.)