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Jan 15, 2023 at 09:21
Today I learnt about a cunning trick used by GNU diff to make Myer's algorithm faster: https://github.com/mitsuhiko/similar/issues/15 If you do an initial pass to find items that only occur on one side, you can discard them before diffing! They'll always be shown as changed.
Implement Myers Heuristics · Issue #15 · mitsuhiko/similar
Implement Myers Heuristics · Issue #15 · mitsuhiko/similar
GNU diff and others have some internal heuristics to bail if there are too many changes. There are basically two optimizations: Discard lines which are completely distinct between two files: this h...

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Mar 10, 2025 at 07:03
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Spent a bunch of time learning about text diffing algorithms this evening. "Myers Algorithm" refers to a specific paper written by Eugene Myers, and he published faster algorithms later!
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Release 0.57.0 · Wilfred/difftastic
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Difftastic is a structural diff tool that understands syntax. See the manual to get started, and the changelog for historical changes. Parsing Text file detection is now stricter, considering null ...
Mar 3, 2024 at 22:56
I'm flattered that SemanticDiff has a blog post comparing it with difftastic! https://semanticdiff.com/blog/semanticdiff-vs-difftastic/ It's a pretty even-handed post, and it touches on some of the different design decisions. For example, SemanticDiff considers 0xA and 10 to be the same when diffing.
SemanticDiff vs. Difftastic: How do they differ?
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SemanticDiff or difftastic: Which one is right for you? Check out our comparison of their inner workings, features, and workflow integration to decide.