E4201

Compiler diagnostic name: struct_constr_inconsistent_impl.

The implementation of a struct constructor must have the same parameter and return types as the constructor declaration in the struct. A method with a different signature is not an implementation of that constructor.

Erroneous example

///|
priv struct Point {
  x : Int

  fn new(Int) -> Point
}

///|
fn Point::new(text : String) -> Point {
  { x: text.length() }
}

Suggestion

Change either the constructor declaration or the Type::new implementation so their signatures match.

///|
priv struct Point {
  x : Int

  fn new(Int) -> Point
}

///|
fn Point::new(x : Int) -> Point {
  { x, }
}

///|
test {
  let point = Point(2)
  inspect(point.x, content="2")
}