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#+date: <2023-02-02 Thu 00:00:00>
#+title: Getting Started with the Hare Language
#+description: Overview of the Hare programming language features, installation procedure, and elementary programming examples targeting system-level development.
#+slug: exploring-hare
#+filetags: :hare:programming:beginner:
* A Quick Note
By no means am I a professional developer, so this post will be rather
short. I won't be going into depth on the specification or anything that
technical.
Instead, I will simply be talking about how I (a relatively basic
hobbyist programmer) have been playing with Hare and what intrigues me
about the language.
* Hare
The [[https://harelang.org][Hare]] programming language is a
straightforward language that should look familiar if you've ever
programmed with C, Rust, or other languages that aim to build software
at the system-level.
The Hare homepage states the following:
#+begin_quote
Hare is a systems programming language designed to be simple, stable,
and robust. Hare uses a static type system, manual memory management,
and minimal runtime. It is well-suited to writing operating systems,
system tools, compilers, networking software, and other low-level, high
performance tasks.
#+end_quote
I have found this all to be true while playing with it for the first
time today. In the next few sections, I'm going to walk through my
installation and first program.
** Installation
I'm currently running Alpine Linux on my Thinkpad, so the installation
was quite easy as there is a package for Hare in the =apk= repositories.
#+begin_src sh
doas apk add hare hare-doc
#+end_src
However, I was able to install Hare from scratch on Fedora Linux a short while
ago, which was also very easy to do. If you need further instructions and Hare
doesn't have a package on your system, take a look at the [[https://harelang.org/installation/][Hare Installation]]
page.
** Creating a Test Project
In order to play with the language, I created [[https://git.cleberg.net/learn.git/tree/hare][learn/hare]] and will be putting any
of my Hare-related adventures in here.
Luckily, Hare doesn't require any complex set-up tools or build
environment. Once you have Hare installed, you simply need to create a
file ending with =.ha= and you can run a Hare program.
I created a file called =rgb.ha= in order to test out the random number
generation and passing parameters between functions.
#+begin_src sh
nano rgb.ha
#+end_src
Within this file, I was able to easily import a few of the
[[https://harelang.org/tutorials/stdlib/][standard library modules]]:
=fmt=, =math::random=, and =datetime=.
With these modules, I created two functions:
1. =main=: This function calls the =generate_rgb= function and then
prints out the returned values.
2. =generate_rgb=: This function uses the current Unix epoch time to
generate a pseudo-random value and uses this value to create three
more random values between 0 and 255. These three numbers represent a
color in RGB format.
#+begin_quote
*Note*: Some syntax coloring may look odd, as Zola currently doesn't
have a syntax highlighting theme for Hare. Instead, I'm using the C
theme, which may not be exactly accurate when coloring the code below.
#+end_quote
#+begin_src C
use datetime;
use fmt;
use math::random;
export fn main() void = {
const rgb = generate_rgb();
fmt::printfln("RGB: ({}, {}, {})", rgb[0], rgb[1], rgb[2])!;
};
fn generate_rgb() []u64 = {
// Use the current Unix epoch time as the seed value
let datetime = datetime::epochunix(&datetime::now());
// Generate initial pseudo-random value
// You must cast the datetime from int to u64
let x = random::init(datetime: u64);
// Generate RGB values between (0, 255) using pseudo-random init value
let r = random::u64n(&x, 255);
let g = random::u64n(&x, 255);
let b = random::u64n(&x, 255);
// Structure data as array and return
let rgb_array: [3]u64 = [r, g, b];
return rgb_array;
};
#+end_src
** Running a Program
Once you have a Hare file written and ready to run, you simply need to
run it:
#+begin_src sh
hare run file.ha
#+end_src
You can also compile the program into an executable:
#+begin_src sh
hare build -o example file.ha
./example
#+end_src
** Initial Thoughts
1. Documentation Improvements Would Help
While I was able to piece everything together eventually, the biggest
downfall right now in Hare's documentation. For such a new project,
the documentation is in a great spot. However, bare specifications
don't help as much as a brief examples section would.
For example, it took me a while to figure out what the =u64n=
function was looking for. I could tell that it took two parameters
and the second was my max value (255), but couldn't figure out what
the first value should be. Eventually, I inspected the =random.ha=
file in the
[[https://git.sr.ht/~sircmpwn/hare/tree/master/item/math/random/random.ha][Hare
source code]] and found the test suite that helped me discover that
it needed an =init()= value in the form of =&var=.
2. More Basic Modules
This is another point that comes from Hare being new and awaiting
more contributions, but there are some basic functions that I would
personally enjoy seeing in Hare, such as one to convert decimal
(base 10) values to hexadecimal (base 16).
If I'm feeling comfortable with my math, I may work on the list of
functions I want and see if any can make it into the Hare source
code.
3. Overall Thoughts
Overall, I actually really enjoy Hare. It's not as tedious to get a
project up and running as Rust, but it's also simpler and more
user-friendly than learning C. I am going to continue playing with it
and see if I can make anything of particular value.
|
