[Drup]

The "inlined" record can only be accessed locally and can not be returned as a single value (See manual here: http://caml.inria.fr/pub/docs/manual-ocaml/extn.html#sec271). In general, multiple types can have the same record fields/constructor names. The typechecker uses type information to figure things out in case of conflicts.

For example:

  type t1 = { foo : int ; bar : int }
  type t2 = { foo : string ; baz : int }

  let x = { foo = 2 ; bar = 2 }
  let y = { foo = "foo" ; baz = 3 }

  let f x = x.foo ^ "x" (* In case of doubt, uses the last one defined *)
  let g (x : t1) = x.foo + 1 (* Uses the types to find the right one *)
  let h { foo ; bar } = foo + bar (* Figure things out using the fields *)

(Of course this is an extreme example, good code should be clearer than that :p)

When a field "foo" comes from a type t in a module M (M.t), you can either use type disambiguation as above or qualify accesses : x.M.foo. All this also works with ADTs.