Implement a type checker

[eWert-Online]

No description provided.

[eWert-Online]

Tags could be defined like this:

external Record(
  label: ?string,
) -> map(#tag);

external Array(
  label: ?string, 
  min: ?int, 
  max: ?int,
) -> array(#tag);

external Int(
  label: ?string, 
  min: ?int, 
  max: ?int
) -> int;

external Image(
  label: ?string,
  crop: ?bool,
  sources: array({
    crop: ?bool,
    width: ?int,
    height: ?int,
  })
) -> {
  alt: string,
  sources: array({
    focal_point: ?{ 
      x: int,
      y: int
    },
    width: int,
    height: int,
    url: string,
  })
}

The attribute of is required as soon as it is a type with "subtypes". (array and map currently)