E4089

Tuple has no field with the given index.

In MoonBit, one can access the element in a tuple using index accessor, like tuple.0, tuple.1, and so on. The index starts with 0, and the compiler will emit this error if you try to access an element that does not exist in the tuple, for example, accessing the third element (tuple.2) in a tuple with only two elements.

Erroneous example

fn main {
  let tuple = (1, 2)
  println(tuple.2)
}

Suggestion

To fix this error, you need to access the element within the tuple that exists.

fn main {
  let tuple = (1, 2)
  println(tuple.1)
}