Flow Control: a programmer's text editor

This is my Zig text editor. It is very much a work-in-progress, but far enough along that I am daily driving it.

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

Requirements

• A modern terminal with 24bit color and kitty keyboard protocol support (kitty and ghostty are the only recommended terminals at this time)
• NerdFonts support
• Linux or MacOS (help porting to *BSD or Windows is welcome!)
• 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

Or, for a slightly smaller executable (with no debug info):

zig build -Doptimize=ReleaseSmall

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.

Run with:

zig-out/bin/flow

MacOS

On MacOS you will need to link Flow against a MacOS build of notcurses 3.0.9. This is easiest with brew:

brew install notcurses
zig build -Doptimize=ReleaseFast -Duse_system_notcurses=true --search-prefix $HOMEBREW_PREFIX

If HOMEBREW_PREFIX is not set in your environment check your brew configuration with brew config.

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

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

Configuration is mostly dynamically maintained with various commands in the UI. It stored under the standard user configuration path. Usually ~/.config/flow.

Files to load may be specifed on the command line:

flow fileA.zig fileB.zig

Common target line specifiers are supported to:

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!)
• vscode compatible keybindings (thanks to kitty keyboard protocol)
• vim compatible keybindings (at least the basics, more to come)
• good unicode support
• 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!