E0070

Warning name: deprecated_for_in_method

Deprecated method name for for .. in iteration.

MoonBit now looks for iter or iter2 when a value is used as the source of a for .. in loop. The old method names iterator and iterator2 still work for now, but they are deprecated.

Erroneous example

///|
priv struct Bag {}

///|
fn Bag::iterator(_self : Bag) -> Iter[Int] {
  [1, 2, 3].iter()
}

///|
fn sum(bag : Bag) -> Int {
  let mut total = 0
  for value in bag {
    total = total + value
  }
  total
}

///|
test {
  inspect(sum(Bag::{  }), content="6")
}

Suggestion

Rename iterator to iter, or iterator2 to iter2.

///|
priv struct Bag {}

///|
fn Bag::iter(_self : Bag) -> Iter[Int] {
  [1, 2, 3].iter()
}

///|
fn sum(bag : Bag) -> Int {
  let mut total = 0
  for value in bag {
    total = total + value
  }
  total
}

///|
test {
  inspect(sum(Bag::{  }), content="6")
}