Yascriptlang

Yet Another Script Language

Because everyone should have their own Lisp

Yascriptlang is high-level and multi-paradigm language. It has curly-bracket syntax, strong dynamic typing, recursion, and first-class functions.

As a multi-paradigm language, yascriptlang supports functional and imperative programming styles both.

Yascriptlang can be interpreted as well as compiled in JavaScript.

Installing

npm install -g yascriptlang

Documentation

The documentation is located in the docs folder.

Usage

Run interpreter:

yas input.yas

Compile to JS:

yasc input.yas output.js

Compile to JS and run:

yasjs input.yas

Building

Pre-reqs

To build and run this app locally you will need a few things:

Install Node.js;

Getting start

Clone the repository

git clone --depth=1 https://github.com/maxbarsukov/yascriptlang.git

Install dependencies

cd yascriptlang
yarn

node bin/yas.js input.yas
# or
node bin/yasc.js input.yas output.js
# or
node bin/yasjs.js input.yas

Examples of code

Here are some code examples. Go to there docs to see more.

Comments:

### Comments
# comment

// comment
/*
multi
line
comment
*/

Strings:

println("Hello World!");
println('Hello World!');
println('Hello " World!');
println("Hello ' World!");
println('My name is ' ++ 'Max'); # => My name is Max

Math:

println(2 + 2 * 2); # => 6
println(3 ** 3); # => 27
println(10 / 5); # => 2
println(17 % 3); # => 2

Variables: (variables are immutable by default)

def pi = 3.14;
println(pi);

def a = {
  10;
  15   # the last semicolon can be missing
};
print(a); # prints 15

def mut b = 1;
b += 2;
b **= 3;
println(b); # => 27

Raw JS:

println(_js_ '[0, 1, 2, 3].length * 2') # => 8
println(_js_ 'console.log("HI!"); 2+4') # => prints HI! and 6
println(_js_ '((a) => { console.log(`HI, ${a}!`)})("Max")') # => prints HI, Max!

Mutable Variables:

def mut a = 3
a = 2;
println(a); # => 2

Functions:

def fib = fn (n) -> if n < 2 then n else fib(n - 1) + fib(n - 2);
println(fib(15));

def print_range = fn(a, b) ->
                if a <= b then {
                  print(a);
                  if a + 1 <= b {
                    print(", ");
                    print_range(a + 1, b);
                  } else println("");
                };
print_range(1, 5); # => 1, 2, 3, 4, 5

def func = fn-> {
  10;
  20;
};

println(func()); # => 20. Functions returns the last var

Lambdas:

# fn-> {} is short for fn() -> {}

(fn->
  println(3 ** 3);
)();

Pipes:

def k = 200;
k |> println; # prints 200

2 |> fn(x) -> (x * x) |> println; # prints 4

Benchmarks:

time(fn-> {
  println(fib(15));
});

Let:

def a = 1;
let (mut a = 10) -> {
    println(a); # => 10
  };
println(a); # => 1


print(let loop(n = 10) ->
  if n > 0 then n + loop(n - 1)
  else 0);
# => 55

let (x = 2, y = x + 1, z = x + y) ->
  println(x + y + z); # => 10


let (x = 10) -> {
  let (x = x * 2, y = x * x) -> {
    println(x); # 20
    println(y); # 400
  };
  println(x); # 10
};

if / else:

def f = fn-> { true; };
def a = if f() then "OK" else "FAIL"; # OK
if 1 == 1 && 2 < 5 then print("OK"); # OK

true / false :

if true then print("OK"); # OK
if !false then print("OK"); # OK
if false then print("Won't be printed");

Lists:

def list = cons(1, cons(2, cons(3, cons(4, cons(5, NIL)))));
print(car(list)); # 1
print(car(cdr(list))); # 2
print(car(cdr(cdr(list)))); # 3
print(car(cdr(cdr(cdr(list))))); # 4
print(car(cdr(cdr(cdr(cdr(list)))))); # 5

Yield:

foo = with-yield(fn(yield) -> {
  yield(1);
  yield(2);
  yield(3);
  "DONE";
});

println(foo()); # 1
println(foo()); # 2
println(foo()); # 3
println(foo()); # DONE

Some stdlib methods:

# foreach
foreach(x, println); # prints from 1 to 5 by println

# range
foreach(range(1, 8), fn(x) -> println(x * x));
# or
foreach(range(1, 8), fn(x) -> (x * x) |> println);
# prints 1, 4, 9, 16, ... 49, 64

# throw / catch
exit = false;
x = 0;
callcc( fn(k) -> exit = k );
if x == 0 then catch("foo", fn-> {
println("in catch");
x = 1;
exit();
});
println("After catch");
throw("foo", "FOO");

License

The package is available as open source under the terms of the MIT License.