nvim

Vanilla nvim, no plugin manager — everything here is a built-in.

Modes

i: insert mode (bar cursor, typing = text)
A: insert at end of current line
a: insert after cursor
o / O: open new line below / above, enter insert mode
Esc: back to normal mode (block cursor, keys = commands)
u: undo last change
Ctrl-r: redo (undo the undo)

Quitting / saving

:w: save
:q: quit (fails if unsaved changes)
:q!: quit without saving (escape hatch)
:wq: save and quit
:x: save and quit only if there were changes

File paths

:e <path>: open a file (replaces current buffer)
:tabnew <path>: open a file in a new tab
:sp <path>: open a file in a horizontal split
:vsp <path>: open a file in a vertical split

Relative paths (:e practice.py) resolve against nvim's cwd, not your last-opened file or your shell prompt's visible dir — check with :pwd.

Motions

/pattern + n/N: search forward, next/previous match
?pattern: search backward
200G or :200: jump to line 200
gg / G: jump to first / last line
0 / $: start / end of current line
w / b: jump forward / backward one word
dd: delete current line
dw: delete word
d$: delete to end of line
yy: yank (copy) current line
p / P: paste after / before cursor

Registers

"ayy: yank current line into register a
"ap: paste register a's contents

Named registers a–z persist until overwritten; unnamed register " holds the most recent yank/delete regardless of a named register.

Macros

qa ... q: record keystrokes into register a, stop recording
@a: replay macro a once
14@a: replay macro a 14 times
@@: replay the last-used macro again

Search / replace

:%s/old/new/g: replace every match, whole file (% = whole file, g = all matches per line)
:s/old/new/g: same, but current line only
:%s/old/new/gc: same as the whole-file version, but confirm each match first

Windows / splits

:sp: split horizontally (new split on top)
:vsp: split vertically (new split on left)
Ctrl-w h/j/k/l: move focus to the split left/down/up/right
Ctrl-w w: cycle focus to the next split
Ctrl-w q: close the current split
Ctrl-w =: resize all splits to equal size

Tabs

:tabnew <path>: open a file in a new tab
gt / gT: next / previous tab
:tabclose: close current tab

LSP (Python via pyright)

Requires pyright on PATH (npm install -g pyright) — auto-attaches to any .py buffer via init.lua's FileType python autocmd. No plugin manager needed; this is nvim's built-in vim.lsp client (0.10+).

gd: go to definition (jumps to where a symbol is actually defined)
K: hover (type info / docstring for whatever's under the cursor)
<leader>e: show the diagnostic under the cursor in a floating window (leader = space)
]d / [d: jump to next / previous diagnostic in the buffer

Scope boundary Pyright catches type/reference errors it can see in the code itself (typo'd method names, wrong argument types). It does NOT catch logic bugs like "no caller actually passes this parameter" — that requires tracing actual call sites, a different and harder problem than type-checking a single file.

netrw (file browser)

Built into nvim — no plugin required. Not a persistent sidebar; each command opens a full directory listing that replaces or splits your current buffer.

:Ex: open netrw in the current window (replaces buffer, like :e but browsable)
:Vex: open netrw in a vertical split (like :vsp)
:Sex: open netrw in a horizontal split (like :sp)
Enter (on a file): open it in the netrw window
%: create a new file at the current netrw location
d: create a new directory
D: delete the file/directory under the cursor (confirms first)
R: rename the file/directory under the cursor

No persistent panel and no git-status-in-tree — for that, a plugin (nvim-tree, neo-tree, oil.nvim) is required, out of scope for this vanilla-nvim setup.

Mode indicator (Warp/tmux specific)

Cursor SHAPE is the real signal: thin bar = insert mode, solid block = normal mode. The text status line at the bottom does not show a mode name in this setup — go by cursor shape, not status-line text.