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Architecture

Two crates in one workspace, and one rule between them: yara-core knows, ycode draws.

crates/yara-core

Everything the editor knows and nothing it shows:

  • follow.rs — the timeline: EditEvents with their hunks, and Follow with its live/paused cursor and the reviewed flags.
  • git.rs — the repository through the git CLI: the base branch, what differs from it, the Watcher that turns movement into edits, the repositories inside a folder of them, worktrees, and pull request titles through gh.
  • pty.rs and keyboard.rs — a program on a pseudo-terminal, its screen parsed by vt100, and the kitty keyboard protocol it may ask for.
  • command.rs, settings.rs, theme.rs — every action and its chord, settings.json, the theme and VS Code theme files.
  • buffer.rs, history.rs, syntax.rs, tree.rs, search.rs, glob.rs, fuzzy.rs, clipboard.rs — the editor, the tree, search and the finders.
  • update.rs, usage.rs — releases through curl, usage through the commands the settings name.

crates/ycode

  • app.rs — App holds the workspace (a Vec<PathBuf> of folders) and its tasks. A Task is a tab: an agent pty, a terminal pty, one timeline, an editor, and the Vec<Folder> it works in — the workspace's folders, or a worktree of each where the task has one of its own. Task::resync points a task at the workspace again, expanding a folder that holds repositories into each of them; App derefs to the active task, so the drawing code reads app.follow and means the one in front. handle_key decides whose key it is, execute runs a Command, and handle_mouse matches a click against the Hits the last frame recorded.
  • ui.rs — every frame: header and tabs, panes, status bar, overlays, hover and selection.
  • keys.rs, theme.rs, main.rs — a key event as a chord, a theme as ratatui styles, and the loop that draws and polls.

How the watching works

Each refresh, every folder is asked whether it moved: a repository through one git status and the modification times of what it lists; a plain folder through a walk of its files. Only a folder that moved is read further, and then each changed file is diffed against what was last seen — so an edit is the step the agent just took. Every file is reported by the folder closest to it, so a repository inside a folder of repositories is not counted twice.

The tests

They drive the real App on ratatui's TestBackend and read the frame back: keys and mouse in, text out. Tests that need git make a real repository in a temp folder; tests that need an agent spawn cat on a real pty. examples/screenshot.rs is the same idea aimed at SVG — a bench of two repositories and a stand-in agent — and it draws every image on these pages.