# 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.

https://github.com/neurocyte/flow/assets/1552770/97aae817-c209-4c08-bc65-0a0bf1f2d4c6

# 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

# Download / Install

Binary release builds are found here: [neurocyte/flow/releases](https://github.com/neurocyte/flow/releases/latest)

Fetch and install the latest release to `/usr/local/bin` with the installation helper script:

```shell
curl -fsSL https://flow-control.dev/install | sh
```

Nightly binary builds are found here: [neurocyte/flow-nightly/releases](https://github.com/neurocyte/flow-nightly/releases/latest)

Install latest nightly build and (optionally) specify the installation destination:

```
curl -fsSL https://flow-control.dev/install | sh -s -- --nightly --dest ~/.local/bin
```

See all avalable options for the installer script:

```
curl -fsSL https://flow-control.dev/install | sh -s -- --help
```

Or check your favorite local system package repository.

[![Packaging status](https://repology.org/badge/vertical-allrepos/flow-control.svg)](https://repology.org/project/flow-control/versions)

# Building

Make sure your system meets the requirements listed above.

Flow builds with zig 0.14.0 at this time. Build with:

```shell
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:

```shell
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:

```shell
zig-out/bin/flow
```

Place it in your path for convenient access:

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

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

```shell
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.

```shell
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:

```shell
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:

```shell
flow file.txt:123
```

Or Vim style:

```shell
flow file.txt +123
```

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

```shell
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

![Discord](https://img.shields.io/discord/1214308467553341470)

Join our [Discord](https://discord.com/invite/4wvteUPphx) server or use the discussions section here on GitHub
to meet with other Flow users!