464c0be2b7
This PR adds word/character diff for expanded diff hunks that have both a deleted and added section, as well as a setting `word_diff_enabled` to enable/disable word diffs per language. - `word_diff_enabled`: Defaults to true. Whether or not expanded diff hunks will show word diff highlights when they're able to. ### Preview <img width="1502" height="430" alt="image" src="https://github.com/user-attachments/assets/1a8d5b71-449e-44cd-bc87-d6b65bfca545" /> ### Architecture I had three architecture goals I wanted to have when adding word diff support: - Caching: We should only calculate word diffs once and save the result. This is because calculating word diffs can be expensive, and Zed should always be responsive. - Don't block the main thread: Word diffs should be computed in the background to prevent hanging Zed. - Lazy calculation: We should calculate word diffs for buffers that are not visible to a user. To accomplish the three goals, word diffs are computed as a part of `BufferDiff` diff hunk processing because it happens on a background thread, is cached until the file is edited, and is only refreshed for open buffers. My original implementation calculated word diffs every frame in the Editor element. This had the benefit of lazy evaluation because it only calculated visible frames, but it didn't have caching for the calculations, and the code wasn't organized. Because the hunk calculations would happen in two separate places instead of just `BufferDiff`. Finally, it always happened on the main thread because it was during the `EditorElement` layout phase. I used Zed's [`diff_internal`](https://github.com/zed-industries/zed/blob/02b2aa6c50c03d3005bec2effbc9f87161fbb1e8/crates/language/src/text_diff.rs#L230-L267) as a starting place for word diff calculations because it uses `Imara_diff` behind the scenes and already has language-specific support. #### Future Improvements In the future, we could add `AST` based word diff highlights, e.g. https://github.com/zed-industries/zed/pull/43691. Release Notes: - git: Show word diff highlight in expanded diff hunks with less than 5 lines. - git: Add `word_diff_enabled` as a language setting that defaults to true. --------- Co-authored-by: David Kleingeld <davidsk@zed.dev> Co-authored-by: Cole Miller <cole@zed.dev> Co-authored-by: cameron <cameron.studdstreet@gmail.com> Co-authored-by: Lukas Wirth <lukas@zed.dev>
Zed
Welcome to Zed, a high-performance, multiplayer code editor from the creators of Atom and Tree-sitter.
Installation
On macOS, Linux, and Windows you can download Zed directly or install Zed via your local package manager.
Other platforms are not yet available:
- Web (tracking issue)
Developing Zed
- Building Zed for macOS
- Building Zed for Linux
- Building Zed for Windows
- Running Collaboration Locally
Contributing
See CONTRIBUTING.md for ways you can contribute to Zed.
Also... we're hiring! Check out our jobs page for open roles.
Licensing
License information for third party dependencies must be correctly provided for CI to pass.
We use cargo-about to automatically comply with open source licenses. If CI is failing, check the following:
- Is it showing a
no license specifiederror for a crate you've created? If so, addpublish = falseunder[package]in your crate's Cargo.toml. - Is the error
failed to satisfy license requirementsfor a dependency? If so, first determine what license the project has and whether this system is sufficient to comply with this license's requirements. If you're unsure, ask a lawyer. Once you've verified that this system is acceptable add the license's SPDX identifier to theacceptedarray inscript/licenses/zed-licenses.toml. - Is
cargo-aboutunable to find the license for a dependency? If so, add a clarification field at the end ofscript/licenses/zed-licenses.toml, as specified in the cargo-about book.