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LANGUAGE.md

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Language

Intro

This file intends to document in a summarised way the syntax of Vetryx, and some topics related to its grammar.

Characteristics of the language

  • Interpreted
  • Dynamically typed
  • High level
  • Imperative

Types

This language only support basic types:

Operator Description
string "hello world"
number Eg: 1. Note: (All numbers are floats for now)
bool true / false
null null value

Operators

Arithmetics

Operator Description
+ Sum two numbers, or concat strings
- Subtract two numbers
* Multiply two numbers
/ Divide two numbers
% Modulus between two numbers

Comparators

Operator Description
== Equal
<> Different
> Greater
>= Greater or Equal
< Lower
<= Lower or Equal

Unary

Operator Description
! Eg: !false => true
- Negates a number. Eg: -(-1) => 1

Logical Operators

Operator Description
&& AND
|| OR

In-built Functions

Operator Description
print prints anything to the stdout
clock returns the current timestamp in nanoseconds (based on the clock)
sleep(X) add a delay of "X" ms to the execution of the program
min(X, Y) returns min
max(X, Y) returns max

Reserved Words

Word
while
break
continue
if
else
dec
fn
return
print
null
true
false

Comments

You can add comments by using #. Example:

# this line will be ignored

Grouping

You can group expressions using parentheses. Example:

print (1+3) * 2; # will print 8, first it resolves the content of parentheses, then the multiplication.

Variables

Declaration

A variable can be declared empty (without assignment), and in such case, will be null by default:

dec a;
print a; # prints null

A variable can be declared and assigned in the same line:

dec a = 1;
print a; # prints 1

A variable can also be declared and assigned using the "short declarator" (similar as in Go):

a := 1;
print a; # prints 1

Assignment

You can assign a value to an existing variable:

dec a;
a = 1;
print a; # prints 1

📌 Important: If the variable is not declared before assignment, the interpreter will throw an error.

If

The syntax for the if condition is:

if "a" == "a" {
    print 1; # will print 1
}

# You can also wrap the condition with parentheses:

if ("a" == "a") {
    print 2; # will print 2
}

If you want to add an else condition, you can also do it:

if ("a" <> "a") {
    print 2; 
} else {
    print 1; # will print 1 in this case
}

While

The syntax for the while loop is:

dec a = 10;
while a < 20 {
    print a; # will print the value of "a" in the current iteration
    a = a + 1;
}

You can also wrap the condition with parentheses:

dec a = 10;
while (a < 20) {
    print a; # will print the value of "a" in the current iteration
    a = a + 1;
}

You can use break to exit the loop:

dec a = 10;
while (a < 20) {
    break; # will exit the loop inmediately
}

You can use continue to move to next iteration of the loop:

dec a = 10;
while (a < 20) {
    a = a + 1;
    if a == 15 {
        continue; # in this case the 15 will not be printed to stdout
    }
    print a;
}

Functions

Declaration

# Without parameters:
fn a() {
    return "x"; # note: if you ommit the return, it will return null by default
}
# With parameters:
fn a(b, c) {
    return b + c;
}

Call

fn a(b, c) {
    return b + c;
}

print a(1, 2); # will print 3

If you want to assign the value to a variable, first you need to declare it, then assign it. Example:

dec x;
x = a(1, 2);
print x; # will print 3

Closures

Closures are supported in the language.

fn buildCounter() {
  i := 0;
  fn count() {
    i = i + 1;
    print i;
  }

  return count
}

dec counter;
counter = buildCounter();

counter(); # Prints 1
counter(); # Prints 2
counter(); # Prints 3