palimpsest

A palimpsest is a manuscript written over scraped-off earlier text, the old strokes still showing through. This crate renders a Pijul change the same way: the whole file, with the change inlined in its context, in three colours —

• added — text the change introduced, still alive;
• removed — text it deleted, shown in place;
• added, then removed — text it introduced that a later change deleted (the scraped-off layer).

The output is a flat, renderer-agnostic stream of Segment { kind: Keep | Add | Del | Obs, text } per file; to_html is a reference renderer, and any UI (CodeMirror decorations, PDF export, a terminal pager…) can colour it. The companion npm package palimpsest-svelte provides ready-made Svelte renderers.

let diffs = palimpsest::change_diff(&pristine, &changes, "main", hash)?;
for file in diffs {
    println!("{}", file.path);
    println!("{}", palimpsest::to_html(&file.segments));
}

Two entry points:

• change_diff — a committed change against the current state of a channel (full graph walk, including the added-then-removed layer);
• record_preview — a recorded but not yet committed change (what a commit dialog shows).

Both need only a pristine and a change store (any ChangeStore implementation): file paths are resolved from the channel graph, so this works on bare repositories — no working copy required.

License and contributions

Dual-licensed AGPL-3.0-or-later OR GPL-2.0-or-later: you may use it under either licence, at your option. The GPL-2.0-or-later arm lets it be linked into the (GPL-2.0) Pijul CLI; standalone/network use can rely on the AGPL arm. The author also uses this library in proprietary products under separate terms; to keep that possible, contributions are only accepted with copyright assignment to the author.