Loops

For

Syntax: for <expression> { <code> }

<expression> should be either an iterable, or an iterable with an extracted value.

Examples:

for 1..10 {
  console.log("Hello, world!")
}

for 1..10 >> count {
  console.log("Count:", count)
}

let fruits = ["apple", "banana", "cherry"]

for fruits >> fruit {
  console.log("Fruit:", fruit)
}

Compile-time for

You can use @for to iterate over a range of values at compile time.

The iterable expression should be a compile-time value.

For example, writing this:

let fruits = @["apple", "banana", "cherry"]

@for fruits >> fruit {
  console.log("Fruit:", fruit)
}

Produces exactly the same code as writing this:

console.log("Fruit:", "apple")
console.log("Fruit:", "banana")
console.log("Fruit:", "cherry")

While

Syntax: while <expression> { <code> }

The code runs until the expression evaluates to false.

Extract a value in the while loop

You can use while with the extract operator >>> to iterate over a range of values at runtime.

while stack.pop() >> value {
	console.log("Popped:", value)
	console.log("Stack length:", stack.length)
}

Loop

Syntax: loop { <code> }

loop is similar to while true. It must have a break or return statement somewhere in the loop body.

Loop as expression

You can use loop as an expression as well:

let found = loop {
  for values >> value {
      if value == target {
          break Some(v)
      }
  }
  break None
}