Editor

Two keymap profiles

mnml has two complete keymaps, and you pick one:

• vim — modes, motions, operators, text objects, registers, the : line, and NvChad's space leader menus. If your fingers know Neovim and NvChad, they know this.
• standard — modeless editing with VS Code's chords: ctrl+p to open a file, ctrl+shift+p for the palette, ctrl+d for the next occurrence.

standard is the default. Choose in the first-launch wizard, with --input vim for one launch, or in config.zon:

.{ .editor = .{ .input_style = .vim } }

Neither profile is the other with patches on top. Each one has its own complete set of chords, and the rest of mnml — the editor, the panes, the renderer — does not know which one is active. The keymap profiles page lists every chord that differs.

A few of the everyday ones:

In the vim profile, pressing space and waiting opens which-key, a menu of everything under the leader. In the standard profile ctrl+k opens the same menu, so every leader chord is reachable from both.

The frame

mnml draws NvChad's chrome: a file tree on the left, a buffer line across the top, a powerline statusline along the bottom, and file-type icons from a Nerd Font. It ships NvChad's 94 base46 colour themes; theme.pick (space t t) previews each as you move through the list. The default is onedark.

Around that frame are the parts you would expect from VS Code: a command palette that finds every command by name and shows its chord, a menu bar and right-click menus whose rows print their chords for your profile, and a mouse that works everywhere — click, drag, resize, scroll. Menus, Tabs and Fields covers the menus, the tab strips, the picker and the text fields.

Splits nest in any direction, and tab pages hold a layout each. layout.save (space W s) keeps the current tab page as a named layout for later; view.toggle_zoom gives one split the whole screen for a moment; view.fullscreen (space t f) hides the chrome.

Even splits

view.equalize_splits (ctrl+w = in the vim profile) shares the current tab page's space equally between its splits, once. To have mnml do that every time a split opens or closes, turn on Auto-equalize splits:

• the Window menu's Auto-equalize splits row, ticked while it is on;
• Settings → UI → Auto-equalize splits;
• view.toggle_auto_equalize_splits from the palette.

With it on, closing one of three splits leaves two even halves instead of one pane twice the size of the other, and turning it on evens the splits out at once. It is off by default, and is written to the workspace's config.zon as ui.auto_equalize_splits.

Integrations are a separate case: a split an integration opens evens out after itself whatever this switch says, unless you set integrations.equalize_on_open = false.

The file tree

Below the top level, every row in the tree carries neo-tree's connectors, folders and files alike: a │ down each level that still has entries to come, and at the row's own level a │ while a sibling follows or a └ on the last child. They are drawn in the theme's comment grey, so they guide the eye without competing with the names. A row nested too deep for the column folds its outer levels into … and keeps its name.

With more than one workspace in the tree (view.add_workspace), each gets a header row, and a workspace dot after the header's chevron marks which one is active: ● on the active workspace, ○ on every other. Click a ○ to switch to that workspace — it opens, the others fold, and the tree takes the keys. A click anywhere else on the header still folds or unfolds it. The same switch is Switch to this workspace on an extra workspace's right-click menu, and view.switch_workspace picks one from a list (ctrl+k ctrl+o in the standard profile). Removing the active workspace hands the dot back to the workspace mnml was opened on.

The dots are on by default. Show workspace dots on the header's right-click menu, the Workspace dots row in the settings overlay, or ui.show_workspace_dots = false turns them off.

The sidebar's width and side

The sidebar is a share of the window, not a fixed number of cells: a fifth of the width, never narrower than 30 cells or wider than 48. That is 30 cells up to a 150-column window, 40 at 200 columns, and 48 from 240 columns on. It follows the window as you resize it.

To fix the width instead, give ui.tree_width a number of cells (10 to 80), in config.zon or the Tree width row of the settings overlay (one step below 10 reads auto, which is 0 in the file):

.{ .ui = .{ .tree_width = 36 } }   // 0, the default, is the share

Dragging the divider between the sidebar and the editor also sets the width, and that width wins over the config: it stays put through resizes and is saved with the session, so it is still there next time you open the workspace. Changing the Tree width row in the settings overlay drops a dragged width and applies the row's value. When mnml reads its configuration again while running — after you trust a workspace, for example — a dragged width survives, unless ui.tree_width itself changed; then the file's value takes over.

Right-click the divider for its menu:

Moving the sidebar moves every section that follows the default side — the file tree, git, sessions and the rest — and it moves the outline, which always takes the side opposite the sidebar. A section you moved by hand, or one ui.section_side places, stays where it is, and the problems list stays in the bottom dock. Auto-hide and Move sidebar are written to your home config.zon; Set width… and a drag are not.

The launcher dock

The launcher dock is a strip of things you start — the + menu, your integrations, a terminal item, and any command you pin — centred along one edge of the editor. On the bottom edge it can sit in one of three places:

Choose with the Launcher dock placement row in the settings overlay, the Place: rows on the strip's right-click menu, or :dock inner, :dock outer and :dock shared (ctrl+; opens the : line in the standard profile). In config.zon it is ui.dock.placement:

.{ .ui = .{ .dock = .{ .placement = .shared } } }

On the command line's row the dock is always up: there is no grip to find it by and no extra row to reveal, so an auto-hide setting reads as always shown there (hidden still hides it). The items sit where ui.dock.align puts them and do not move while you type. Only when a long command would reach them does the strip step aside — it is not drawn while the command is that long, and it comes back as soon as the line closes or gets shorter. With the items aligned to the start of the row they step aside as soon as a line opens, so keep the default centred alignment, or end, to see them while you type.

Editing

• Multiple cursors. Every cursor types, deletes, selects and pastes. ctrl+d (standard) adds the next occurrence, ctrl+shift+l selects them all, and ctrl+alt+up / down add a cursor above or below.
• Vim's toolkit, in the vim profile: counts, dot-repeat, registers, marks (capital marks persist across sessions), macros, visual block, text objects, surround (ys, ds, cs), gq reflow, and ctrl+a / ctrl+x on numbers.
• Snippets with tab stops that follow the text as you type.
• Folds, and sticky context: the header of the function or block you are in stays pinned above the text.
• Harpoon: pin the files you keep coming back to (space H a) and jump between them (space H m).

Undo is grouped the way you would expect: typing over a selection is one undo step.

Syntax highlighting

Highlighting is tree-sitter, with 41 grammars compiled into the binary — nothing to download. It updates incrementally as you type, and it understands embedded languages: code fenced in Markdown, <script> and <style> in HTML.

Language servers

mnml speaks the Language Server Protocol to whatever servers you have installed: diagnostics, completion, hover, signature help, go to definition and references, rename, formatting, code actions, document symbols, and semantic highlighting.

An external formatter (Prettier, rustfmt, Ruff and others) runs instead of the server when the project is configured for one.

Debugging

mnml is a Debug Adapter Protocol client: breakpoints, stepping, the call stack, watches, and a REPL pane. f9 toggles a breakpoint and f5 starts or continues, in both profiles.

Markdown and images

markdown.preview (space m) renders a Markdown file in a pane beside it. Images — PNG, JPEG and GIF — display in terminals that support the Kitty, iTerm2 or sixel image protocols.

Files on disk

Open files are checked every two seconds. A file that changed on disk reloads if you have not edited it; if you have, mnml warns you instead of overwriting either side.