Editing

Tabs

Open files sit in a strip over the editor, with a dot while they have unsaved changes and a cross once the pointer is over them. Drag a tab onto another to reorder; Ctrl+PageUp / Ctrl+PageDown walk the strip. Diffs open as tabs of their own beside the files — see Git.

Getting around

• Command Palette (Cmd+Shift+P / Ctrl+Shift+P) lists every command by name with its chord; type a few letters, the rows narrow to what matches, Enter runs the top one. Everything in the menus is here too, so nothing needs remembering.
• Go to File (Cmd+P / Ctrl+P) does the same over every file in the project — gapp finds src/gui/app.rs — and opens the pick.
• Go to Line (Ctrl+G in both) jumps within the file in front.

The mouse wheel scrolls the view without moving the caret; the next keystroke brings the view back to it. A line wider than the pane scrolls sideways under the caret rather than hiding it.

Undo and redo

Cmd+Z / Ctrl+Z and Cmd+Shift+Z / Ctrl+Shift+Z. Every change is undoable, including Replace All and a replace inside the find bar.

A run of typing folds into a single step, so undo takes back a word rather than a letter; moving the cursor closes the run; a bulk rewrite always stands alone. Each buffer keeps 200 steps, and the cursor returns to where the step left it.

Smart indent

Enter continues the current indentation, opens a block after : (Python, YAML) or { ( [, dedents after return / pass / break / continue / raise, and splits bracket pairs onto their own lines. The indent unit — tabs, 2, 4 or 8 spaces — is inferred from the file being edited unless indent.detect_from_file is off.

Folding

Every indented block folds, in both frontends: click the marker in the gutter, or use Fold / Unfold (Cmd+Alt+F / Ctrl+Alt+F), Fold All (Cmd+Alt+0) and Unfold All (Cmd+Alt+9). Brace languages take their closing line with them, and a collapsed block shows how many lines it swallowed. Folds are dropped when an edit moves their header.

Sticky scroll: the headers of the blocks you are inside stay pinned at the top of the editor while you scroll, syntax highlighted, with their real line numbers, up to three deep.

Markdown preview

TerminalWindow

Cmd+Shift+V / Ctrl+Shift+V, or ◫ Preview on the tab strip, renders the markdown file in front in a tab of its own, and follows it keystroke by keystroke. Both frontends draw the same document:

• Headings, ruled under the first two levels, with emphasis, inline code and links inside them.
• Lists of every kind — bulleted, numbered from the number written, and ticked (- [x] / - [ ]), nested as deep as the indentation goes, with a bullet per level.
• Tables, with the alignment their :---: row asks for.
• Quotes, fenced code with its language, and rules.
• Charts: a ```mermaid block is drawn as a picture where it is a pie or a flowchart/graph — boxes, arrows and the labels on them, laid out the same way in both frontends. Every other mermaid diagram is left as the code it was written as, which is easier to read than a wrong picture.
• Images, as the alt text they were described as: neither frontend fetches or decodes a picture, and a README's badges say what they say in their names. A badge written the usual way — a link wrapped round an image — stays the link it is.
• Raw HTML is markup for a browser and is not painted. The one thing it is obeyed for is centring: what a <div align="center"> holds is centred, which is how most READMEs set their title, their badges and their screenshot.

Go to definition

F12 at the cursor, Cmd+click in the window, Ctrl+click or Alt+click in the terminal (the xterm mouse protocol carries Shift, Alt and Ctrl, never Cmd). Holding the modifier underlines the identifier under the pointer.

It is a keyword heuristic across Rust, Python, JS/TS, Go, Swift, Java/Kotlin, C# and proto — not an LSP — and it falls back to listing references. Ctrl+- (window) / Alt+← (terminal) goes back.

Files that change outside the editor

A formatter, a script, an agent, another editor: once a second every open file is checked against the disk. A file you have not touched takes the new text silently and the status bar says main.rs changed on disk — reloaded — the reload is one undo step, so it can be taken back. A file with unsaved edits keeps them and says changed on disk — saving will overwrite it, so nothing of yours is lost without being asked.

The navigator

Arrows or j/k move, Enter opens or expands. New file, new folder, rename, move and delete are on the context menu (right-click, or Shift+F10), and each has a binding of its own — F2 renames, Shift+Delete deletes.

Drag a row onto a folder to move it; the target folder highlights, and dropping on empty space moves to the project root.