Flow Control: a programmer's text editor

This is my Zig text editor. It is under active development, but usually stable and is my daily driver for most things coding related.

2024-02-15_15-38-00.-.flow.announcement.mp4

Requirements

• A modern terminal with 24bit color and, ideally, kitty keyboard protocol support. Kitty, Foot and Ghostty are the only recommended terminals at this time. Most other terminals will work, but with reduced functionality.
• NerdFont support. Either via terminal font fallback or a patched font.
• Linux, MacOS, Windows, Android (Termux) or FreeBSD.
• A UTF-8 locale

Building

Make sure your system meets the requirements listed above.

Flow builds with zig 0.13 at this time. Build with:

zig build -Doptimize=ReleaseSafe

Zig will by default build a binary optimized for your specific CPU. If you get illegal instruction errors add -Dcpu=baseline to the build command to produce a binary with generic CPU support.

Thanks to Zig you may also cross-compile from any host to pretty much any target. For example:

zig build -Doptimize=ReleaseSafe -Dtarget=x86_64-windows --prefix zig-out/x86_64-windows
zig build -Doptimize=ReleaseSafe -Dtarget=x86_64-macos-none --prefix zig-out/x86_64-macos
zig build -Doptimize=ReleaseSafe -Dtarget=aarch64-linux-musl --prefix zig-out/aarch64-linux

When cross-compiling zig will build a binary with generic CPU support.

Running Flow Control

The binary is:

zig-out/bin/flow

Place it in your path for convenient access:

sudo cp zig-out/bin/flow /usr/local/bin

Or if you prefer, let zig install it in your home directory:

zig build -Doptimize=ReleaseSafe --prefix ~/.local

Flow Control is a single statically linked binary. No further runtime files are required. You may install it on another system by simply copying the binary.

scp zig-out/bin/flow root@otherhost:/usr/local/bin

Configuration is mostly dynamically maintained with various commands in the UI. It is stored under the standard user configuration path. Usually ~/.config/flow on Linux. %APPDATA%\Roaming\flow on Windows. Somewhere magical on MacOS

Logs, traces and per-project most recently used file lists are stored in the standard user application state directory. Usually ~/.local/state/flow on Linux and %APPDATA%\Roaming\flow on Windows.

Files to load may be specifed on the command line:

flow fileA.zig fileB.zig

The last file will be opened and the previous files will be placed in reverse order at the top of the recent files list. Switch to recent files with Ctrl-e.

Common target line specifiers are supported too:

flow file.txt:123

Or Vim style:

flow file.txt +123

Use the --language option to force the file type of a file:

flow --language bash ~/.bash_profile

Show supported language names with --list-languages.

See flow --help for the full list of command line options.

Key bindings and commands

Press F2 to switch the current keybinding mode. (flow, vim, emacs, etc.) Press ctrl+shift+p or alt+x to show the command palette. Press ctrl+F2 to see a full list of all current keybindings and commands.

Run the Edit keybindings command to save the current keybinding mode to a file and open it for editing. Save your customized keybinds under a new name in the same directory to create an entirely new keybinding mode. Keybinding changes will take effect on restart.

Terminal configuration

Kitty, Ghostty and most other terminals have default keybindings that conflict with common editor commands. I highly recommend rebinding them to keys that are not generally used anywhere else.

For Kitty rebinding kitty_mod is usually enough:

kitty_mod ctrl+alt

For Ghostty each conflicting binding has to be reconfigured individually.

Features

• fast TUI interface. no user interaction should take longer than one frame (6ms) (even debug builds)
• tree sitter based syntax highlighting
• linting (diagnostics) and code navigation (goto definition) via language server
• multi cursor editing support
• first class mouse support (yes, even with a scrollbar that actually works properly!) (Windows included)
• vscode compatible keybindings (thanks to kitty keyboard protocol)
• vim compatible keybindings (the standard vimtutor bindings, more on request)
• user configurable keybindings
• excellent unicode support including 2027 mode
• hybrid rope/piece-table buffer for fast loading, saving and editing with hundreds of cursors
• theme support (compatible with vscode themes via the flow-themes project)
• infinite undo/redo (at least until you run out of ram)
• find in files
• command palette
• stuff I've forgotten to mention...

Features in progress (aka, the road to 1.0)

• completion UI/LSP support for completion
• persistent undo/redo
• file watcher for auto reload

Features planned for the future

• multi tty support (shared editor sessions across multiple ttys)
• multi user editing
• multi host editing

Community

Join our Discord server or use the discussions section here on GitHub to meet with other Flow users!