Returns and Jumps

return Statement

The return statement returns the provided evaluated expression to the caller and stop execution of the function. If no expression is provided to return, then nil will be returned implicitly.

fn is_non_nil(value) {
  if (value == nil) {
    return false;
  }

  return true;
}

println(is_non_nil("Hello World!")); // true
println(is_non_nil(false)); // false

break and continue

break and continue statemtents can be used to control execution of the loop. They must be used in the same function scope that the loop is declared in.

break statements can be used to stop execution of the loop.

var arr = [0, 1, 2, 3];
var first_non_zero_number;
for (var i = 0; i < arr.length(); i +=1) {
  var item = arr[i];
  if (item != 0) {
    first_non_zero_number = item;
    break;
  }
}
println(first_non_zero_number); // 1

continue statements can be used to stop execution of just that iteration, allowing the loop to continue.

var arr = [0, 1, 2, 3];
for (var i = 0; i < arr.length(); i += 1) {
  var item == arr[i];
  if (item % 2 != 0) {
    continue;
  }

  println(item);
}
// 0
// 2

Logical Short-Circuit Operations

The and and or operators can be used to short-circuit logic.

false and assert(false) // This assertion is never called.

true or assert(false) // This assertion is never called.