slice-diff-patch

This crate provides the Change enum as an abstraction for diff::Result, lcs_diff::DiffResult, and wu_diff::DiffResult; the diff_changes(), diff_diff(), lcs_changes(), lcs_diff(), wu_changes(), and wu_diff() functions to calculate or process diffs between a and b slices via LCS (Longest Common Subsequence) or Wu diff algorithms into a Vec<Change>, the patch() function to reproduce b from the a slice and Vec<Change>, and the insert() and remove() functions to enable writing a custom changes function.

use slice_diff_patch::*;

let a = vec!["one", "TWO", "three", "four"];
let b = vec!["zero", "one", "two", "four"];

let diff = diff_diff(&a, &b);
assert_eq!(
    diff,
    vec![
        Change::Insert((0, "zero")),
        Change::Remove(2),
        Change::Update((2, "two")),
    ],
);
assert_eq!(patch(&a, &diff), b);

let lcs = lcs_diff(&a, &b);
assert_eq!(
    lcs,
    vec![
        Change::Insert((0, "zero")),
        Change::Update((2, "two")),
        Change::Remove(3),
    ],
);
assert_eq!(patch(&a, &lcs), b);

let wu = wu_diff(&a, &b);
assert_eq!(
    wu,
    vec![
        Change::Insert((0, "zero")),
        Change::Remove(2),
        Change::Update((2, "two")),
    ],
);
assert_eq!(patch(&a, &wu), b);

See also:

• Hunt, James W; Szymanski, Thomas G. (1977). "A fast algorithm for computing longest common subsequences" http://www.cs.ust.hk/mjg_lib/bibs/DPSu/DPSu.Files/HuSz77.pdf
• Wu, Sun; Manber, Udi; Myers, Gene (1989). "An O(NP) Sequence Comparison Algorithm" https://publications.mpi-cbg.de/Wu_1990_6334.pdf
• Department of Mathematics and Computer Science. University of Southern Denmark (January 12, 2017). "The Hunt-Szymanski Algorithm for LCS" https://imada.sdu.dk/~rolf/Edu/DM823/E16/HuntSzymanski.pdf
• diff crate
• lcs-diff crate
• wu-diff crate
• Wikipedia: Hunt–Szymanski algorithm
• Wikipedia: Bitap algorithm
• Practical use case analysis

Changelog:

• 0.1.0: initial
• 0.2.0: add support for diff crate
• 0.2.1: fix readme
• 0.2.2: fix readme
• 0.3.0: derive Clone on Change
• 1.0.0: add Update variant on Change
• 1.1.0: add doc test example
• 1.1.1: fix readme
• 1.2.1: expose remove() and insert() functions