Patience Diff

Myers diff sometimes produces "ugly" diffs for code:

Original:
  function foo() {
    return 1;
  }
  function bar() {
    return 2;
  }

Modified:
  function bar() {
    return 2;
  }
  function foo() {
    return 1;
  }

Myers might produce a confusing minimal-edit diff. Patience diff (Bram Cohen, 2009) produces clearer diffs by:

1. Find LINES that appear EXACTLY ONCE in both files. These are "unique anchor" lines.
2. Find the longest common subsequence of these anchor lines.
3. The anchors split each file into chunks; recursively diff each chunk.

The result is more visually intuitive — large block reorders show as block moves.

git diff --patience enables it. --histogram is similar but faster.

For most code review tools (GitHub, Gerrit), the diff visualization matters more than minimality. Patience and histogram produce diffs people understand more easily.