The V Programming Language

vlang.io | Docs | Changelog | Speed | Contributing & compiler design

Key Features of V

• Simplicity: the language can be learned in a weekend
• Fast compilation: ≈110k loc/s with a Clang backend, ≈500k loc/s with native and tcc backends (Intel i5-7500, SSD, no optimization) (demo video)
• Easy to develop: V compiles itself in less than a second
• Performance: as fast as C (V's main backend compiles to human-readable C)
• Safety: no null, no globals, no undefined behavior (wip), immutability by default
• C to V translation (Translating DOOM demo video)
• Hot code reloading
• Flexible memory management. GC by default, manual via v -gc none, arena allocation via v -prealloc, autofree via v -autofree (autofree demo video).
• Cross-platform UI library
• Built-in graphics library
• Easy cross-compilation
• REPL
• Built-in ORM
• Built-in web framework
• C and JavaScript backends
• Great for writing low-level software (Vinix OS)

Stability guarantee and future changes

Despite being at an early development stage, the V language is relatively stable and has backwards compatibility guarantee, meaning that the code you write today is guaranteed to work a month, a year, or five years from now.

There still may be minor syntax changes before the 1.0 release, but they will be handled automatically via vfmt, as has been done in the past.

The V core APIs (primarily the os module) will still have minor changes until they are stabilized in V 1.0. Of course the APIs will grow after that, but without breaking existing code.

Unlike many other languages, V is not going to be always changing, with new features being introduced and old features modified. It is always going to be a small and simple language, very similar to the way it is right now.

Installing V from source

--> (this is the preferred method)

Linux, macOS, Windows, *BSD, Solaris, WSL, etc.

Usually installing V is quite simple if you have an environment that already has a functional git installation.

To get started, simply try to execute the following in your terminal/shell:

git clone https://github.com/vlang/v
cd v
make
# HINT: Using Windows? run make.bat in a cmd shell, or ./make.bat in PowerShell

That should be it and you should find your V executable at [path to V repo]/v. [path to V repo] can be anywhere.

(As in the hint above, on Windows make means running make.bat.)

Now you can try ./v run examples/hello_world.v (or v run examples/hello_world.v in cmd shell).

• Trouble? Please see the note above and link to Installation Issues for help.

V is constantly being updated. To update V, simply run:

v up

Note

If you run into any trouble, or you have a different operating system or Linux distribution that doesn't install or work immediately, please see Installation Issues and search for your OS and problem.

If you can't find your problem, please add it to an existing discussion if one exists for your OS, or create a new one if a main discussion doesn't yet exist for your OS.

C compiler

The Tiny C Compiler (tcc) is downloaded for you by make if there is a compatible version for your system, and installed under the V thirdparty directory.

This compiler is very fast, but does almost no optimizations. It is best for development builds.

For production builds (using the -prod option to V), it's recommended to use clang, gcc, or Microsoft Visual C++. If you are doing development, you most likely already have one of those installed.

Otherwise, follow these instructions:

• Installing a C compiler on Linux and macOS

• Installing a C compiler on Windows

Symlinking

Note

It is highly recommended, that you put V on your PATH. That saves you the effort to type in the full path to your v executable every time. V provides a convenience v symlink command to do that more easily.

On Unix systems, it creates a /usr/local/bin/v symlink to your executable. To do that, run:

sudo ./v symlink

On Windows, start a new shell with administrative privileges, for example by pressing the Windows Key, then type cmd.exe, right-click on its menu entry, and choose Run as administrator. In the new administrative shell, cd to the path where you have compiled V, then type:

v symlink

(or ./v symlink in PowerShell)

That will make V available everywhere, by adding it to your PATH. Please restart your shell/editor after that, so that it can pick up the new PATH variable.

Note

There is no need to run v symlink more than once - v will still be available, even after v up, restarts, and so on. You only need to run it again if you decide to move the V repo folder somewhere else.

Void Linux

Expand Void Linux instructions

# xbps-install -Su base-devel
# xbps-install libatomic-devel
$ git clone https://github.com/vlang/v
$ cd v
$ make

Docker

Expand Docker instructions

git clone https://github.com/vlang/v
cd v
docker build -t vlang .
docker run --rm -it vlang:latest

Docker with Alpine/musl

git clone https://github.com/vlang/v
cd v
docker build -t vlang --file=Dockerfile.alpine .
docker run --rm -it vlang:latest

Termux/Android

On Termux, V needs some packages preinstalled - a working C compiler, also libexecinfo, libgc and libgc-static. After installing them, you can use the same script, like on Linux/macos:

pkg install clang libexecinfo libgc libgc-static make git
git clone https://github.com/vlang/v
cd v
make

Testing and running the examples

Make sure V can compile itself:

$ v self
$ v
V 0.3.x
Use Ctrl-C or `exit` to exit

>>> println('hello world')
hello world
>>>

cd examples
v hello_world.v && ./hello_world    # or simply
v run hello_world.v                 # this builds the program and runs it right away

v run word_counter/word_counter.v word_counter/cinderella.txt
v run news_fetcher.v
v run tetris/tetris.v

In order to build Tetris or 2048 (or anything else using sokol or gg graphics modules), you will need additional development libraries for your system.

System	Installation method
Debian/Ubuntu based	sudo apt install libxi-dev libxcursor-dev libgl-dev
Fedora/RH/CentOS	sudo dnf install libXcursor-devel libXi-devel libX11-devel libglvnd-devel
NixOS	add xorg.libX11.dev xorg.libXcursor.dev xorg.libXi.dev libGL.dev to environment.systemPackages

V net.http, net.websocket, v install

The net.http module, the net.websocket module, and the v install command may all use SSL. V comes with a version of mbedtls, which should work on all systems. If you find a need to use OpenSSL instead, you will need to make sure that it is installed on your system, then use the -d use_openssl switch when you compile.

To install OpenSSL on non-Windows systems:

System	Installation command
macOS	brew install openssl
Debian/Ubuntu based	sudo apt install libssl-dev
Arch/Manjaro	openssl is installed by default
Fedora/CentOS/RH	sudo dnf install openssl-devel

On Windows, OpenSSL is simply hard to get working correctly. The instructions here may (or may not) help.

V sync

V's sync module and channel implementation uses libatomic. It is most likely already installed on your system, but if not, you can install it, by doing the following:

System	Installation command
macOS	already installed
Debian/Ubuntu based	sudo apt install libatomic1
Fedora/CentOS/RH	sudo dnf install libatomic-static

V UI

https://github.com/vlang/ui

Android graphical apps

With V's vab tool, building V UI and graphical apps for Android can become as easy as:

./vab /path/to/v/examples/2048

https://github.com/vlang/vab.

Developing web applications

Check out the Building a simple web blog tutorial and Gitly, a light and fast alternative to GitHub/GitLab:

https://github.com/vlang/gitly

Vinix, an OS/kernel written in V

V is great for writing low-level software like drivers and kernels. Vinix is an OS/kernel that already runs bash, GCC, V, and nano.

https://github.com/vlang/vinix

Acknowledgement

V thanks Fabrice Bellard for his original work on the TCC - Tiny C Compiler. Note the TCC website is old; the current TCC repository can be found here. V utilizes pre-built TCC binaries located at https://github.com/vlang/tccbin/.

Troubleshooting

Please see the Troubleshooting section on our wiki page