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 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.
• NerdFonts support
• Linux, MacOS, (somewhat experimental) Windows, Android (Termux) or FreeBSD. Other BSDs probably work too, but nobody has tried it yet.
• A UTF-8 locale (very important!)

Building

Make sure your system meets the requirements listed above.

Flow tracks zig master most of the time. Build with:

zig build -Doptimize=ReleaseFast

Sometimes zig master may introduce breaking changes and Flow may take a few days to catch up. In that case there is a simple zig wrapper script provided that will download and build with the last known compatible version of zig. The version is stored in build.zig.version.

Build with the zig wrapper:

./zig build -Doptimize=ReleaseFast

The zig wrapper places the downloaded zig compiler in the .cache directory and does not touch your system. It requires bash, curl and jq to run.

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

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

Running Flow Control

The output binary is:

zig-out/bin/flow

Place it in your path for convenient access:

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

Flow Control is a single statically linked binary. No further runtime is 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 stored under the standard user configuration path. Usually ~/.config/flow. (%APPDATA%\Roaming\flow on Windows)

Logs, traces and per-project most recently used file lists are stored in the standard user runtime cache directory. Usually ~/.cache/flow.

Files to load may be specifed on the command line:

flow fileA.zig fileB.zig

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

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

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!) (no mouse support on Windows yet)
• vscode compatible keybindings (thanks to kitty keyboard protocol)
• vim compatible keybindings (the standard vimtutor bindings, more on request)
• 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)
• stuff I've forgotten to mention...

Features in progress (aka, the road to 1.0)

• completion UI/LSP support for completion
• find in files
• command palette
• persistent undo/redo
• file watcher for auto reload

Features planned for the future

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

Community

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