This tool uses Python's difflib to generate diffs and allow for merges between
strings (not files!).
The difference between this and most tools is that the text and the diffs do
not have to be files in a filesystem! It allows for, say, the storage of diffs
in a database, to be pulled out and applied dynamically within your program. No
files need to be created or deleted, and no physical repository need exist on
the server.
I created this tool to help out with another project (author_collab), but given
its clear use cases, I thought I would keep it separate and allow anyone to use
this as a package. I am open to code contributions from others.
If you make use of this, let me know!
--------------------
A simple example of its usage:
import merge_in_memory as mim_module
str1 = """line 1
line 2"""
str2 = """line 1
line 2 changed"""
merger = mim_module.Merger()
print merger.diff_make(str1, str2)
This will output:
---
+++
@@ -1,2 +1,2 @@
line 1
-line 2
+line 2 changed
diffs are simply strings (rather than generators, as they are when using
difflib).You can create a number of diffs and apply them at once (ie.
fast-forward through a history or track back) with the `diff_apply_bulk()`
function.
To reverse into the history, simply ensure that the `reverse` attribute is set
to True when calling either `diff_bulk()` or `diff_apply_bulk`. For example:
merge = self.inline_merge.diff_apply_bulk(text3, [diff1, diff2], reverse=True)
If you start with text1 and generated text2 and text3 with diff1 and diff2,
then text1 is rebuilt with the above line of code. Note that the list of diffs
are still in ascending order. A 'merge', ie. applying a diff to a string, is
itself a string.
All of this allows one to store diffs in the database as simple VARCHARs (or
what-have-you). I can pull them out in order and apply them in either
direction to generate the text I want, as long as I have a starting point.