Crate 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

Enums

Change

Abstraction for diff::Result, lcs_diff::DiffResult, and wu_diff::DiffResult that excludes a variant for common sequence, stores a clone of inserted items, and indices relate iteratively to a.

Functions

diff_changes

Convert a slice of diff::Result into a Vec<Change>.

diff_diff

Calculate the diff between a and b via diff::slice and convert to a Vec<Change>.

insert

Process an insert.

lcs_changes

Convert a slice of lcs_diff::DiffResult into a Vec<Change>.

lcs_diff

Calculate the diff between a and b via lcs_diff::diff and convert to a Vec<Change>.

patch

Reproduce b from the a slice and Vec<Change>.

remove

Process a remove.

wu_changes

Convert a slice of wu_diff::DiffResult into a Vec<Change>.

wu_diff

Calculate the diff between a and b via wu_diff::diff and convert to a Vec<Change>.