perlang

Perlang is a general-purpose programming language aimed at being "concurrently safe, fast and fun". Its current implementation is an interpreter implemented in C#, with some compiler-like characteristics for performing static code analysis.

The aim is to make it a fully compiled language in the long run (either to MSIL or machine code), while still remaining low-barrier and low-entry. You should never have to install a lot of packages/complex tooling to be able to start writing Perlang code; it should always remain just a single command away.

Installation

The Perlang tools are installed using perlang-install. It works on all supported platforms (Linux, macOS and Windows), as long as you have a POSIX compatible shell available, e.g. bash. Use it like this:

$ curl -sSL https://perlang.org/install | sh

The installer will refuse to overwrite an existing installation, if present. If this happens, you can force the install like this:

$ curl -sSL https://perlang.org/install | sh -s -- --force

The installer will download the latest Perlang build and unpack it in a folder under ~/.perlang. It will also print some instructions about how to add the Perlang toolchain to your $PATH.

Hello World

// hello_world.per
print "Hello World";

Running this will give you the following:

$ perlang hello_world.per
Hello World

Printing the first 1000 digits of pi

The first digit printed is 3, and the first 999 decimals is then printed immediately after.

var digits = 1000;

var i = 1;
var x = 3 * (10 ** (digits + 20));
var pi = x;

while (x > 0) {
    x = x * i / ((i + 1) * 4);
    pi += (x / (i + 2));
    i += 2;
}

print(pi / (10 ** 20));

Further reading

• https://perlang.org/learn/quickstart/index.html - this page contains more examples and explains the basics of the Perlang REPL, which is a great tool for playing around with the language.

More details

Building from source

Note: this is not required for writing Perlang programs. These steps are required if you want to make changes to the Perlang code itself.

Installing prerequisites for building

$ sudo apt-get install \
      dotnet-sdk-7.0 \
      make \
      ruby

Building the Perlang tooling

$ git clone https://gitlab.perlang.org/perlang/perlang.git
$ cd perlang
$ make

You should now have a perlang executable. Run make run to run it. If you are brave, make install (currently Linux only) will put binaries in a path under ~/.perlang which you can put in your $PATH so you can easily use it from anywhere.

Note: this script uses the same folder (~/.perlang/nightly/bin) as the nightly build installer. Any previous version will be overwritten without prompting. This means that if you have previously installed a nightly build and added the folder to your $PATH, the version installed with make install will now be available in the $PATH instead of the previous nightly version.

Documentation

• docs/syntax-grammar.md: Specification of the syntax grammar for the Perlang language.
• docs: The source code to the https://perlang.org web site. Built using docfx.

Building the docs

Install the DocFX prerequisites, including the Mono runtime. You should then be able to run the following:

$ npm install -g live-server
$ make docs
$ make docs-serve

When you make changes to the documentation, run make docs to regenerate them. The live-server process which is started by make docs-serve will conveniently make your browser auto-reload the changes.

If you want to continuously rebuild documentation, run make docs-autobuild in a separate terminal window. This does not currently work flawlessly, so the make docs approach is preferable.

Published builds

Each commit to the master branch triggers a build that gets published as a set of .tar.gz files at https://builds.perlang.org (CDN sponsored by Fastly). Binaries are available for Linux, macOS and Windows. These builds can be installed using the perlang-install script mentioned earlier in this guide.

License

MIT (Expat)

perlang-install is originally based on rustup-init, which is also licensed under the MIT license. Copyright (c) 2016 The Rust Project Developers.

src/Perlang.Stdlib/Stdlib/Posix.cs includes content from the NetBSD project, licensed under the 3-clause BSD license. Copyright (c) 1980, 1991, 1993 The Regents of the University of California. All rights reserved.

src/stdlib/src/bigint.hpp includes content from Syed Faheel Ahmad's BigInt library, available at https://github.com/faheel/BigInt, licensed under the terms of the MIT license. Copyright (c) 2017 - 2018 Syed Faheel Ahmad.

src/stdlib/src/libtommath includes content from libtommath (https://github.com/libtom/libtommath), licensed under the Unlicense (http://unlicense.org).

src/stdlib/src/fmt includes content from the {fmt} library, available at https://github.com/fmtlib/fmt, licensed under the MIT license. Copyright (c) 2012 - present, Victor Zverovich and {fmt} contributors.

Third-party libraries

The src/stdlib directory uses Catch2 for unit testing, which is available under the Boost Software License 1.0.

Disclaimer

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.