Toylang

Toy language created in Rust for educational purposes.

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Example

Simple program to calculate the factorial of a number (n) and exit with the factorial.

let fact = 1;
let n = 5;
if(n == 0 or n == 1) {
    fact = 1;
}
while (n>1) {
        fact *= n;
        n-=1;
      }
}
  exit(fact);

Description

Now theres two

Usage

Compiling

cargo run <project-name>.tl <compilation-mode>

Compiltion modes

Bytecode (b):

Creates a .basm file which can be executed with the Basm Virtual Machine

Native (c):

This creates a binary which can then be executed. Not recommended as it can only be execute on one type of machine and lacks language features. The development for this compilation mode is paused. Development might continue in the future.

Viewing output

Currently, there is no printing to the screen directly. You have to use the exit() function with some integer exit code. If you're using the bytecode version, it outputs to the screen then exits. If youre using Native compiler view it using echo %ERRORLEVEL% on windows.

Variables

Variables are declared with the let keyword.

let x = 34;
let y = x + 1;
let z = true;

There are currently 4 types:

• Bool
• Int32
• Infer
• Void

let bool = true;
let int = 420;

Infer type is for the compiler when it doesn't know what value the variable has. All variables are set to Infer then converted to whatever type there is on the other side of the assignment. You would almost never have to use this. Variables cannot be assigned different types. Void is still in development.

let int = 1;
int = false;

Gives an error saying you can't assign int which has the type Int32 to Bool.

If and else statements

if (some_condition) {

}else if (some_other_condition) {

}else {

}

While loop:

while(condition) {

}

Comparisions and other assignment also included.

Functions

They start with the fn keyword. General Structure:

fn <ident>(<type> <argIdent1>, <type> <argIdent2>,...,<type> <argIdentN>) : <optional-return-type>  {
  function body;
}

Example: Program to get the nth number in the fibbonacci series.

fn fib(int32 n): int32 {
  let ans = 1;
  let prev1 = 1;
  let prev2 = 0;
  while(n!=0) {
    ans = prev1+prev2;
    prev2 = prev1;
    prev1 = ans;
  
  n -= 1;
  }
  return ans;
}

exit(fib(40));