The generativity of record types is, I believe, one of the key prereqs for
achieving a decidable type inference algorithm in the absence of any type
annotations, in caml.  That is, when you write a caml program and it fails
to type-check, you can't make it type-check by adding "enough"
type-annotations.  For a programmer, this is critical -- when the compiler
tells you that your program doesn't type-check, it means that your code is
actually broken.  Whereas in SML/NJ, you might need to add some more
type-annotations.

It was one of the things that convinced me to switch to caml, lo these many
decades.

On Tue, Jan 23, 2018 at 8:05 AM, Jeremy Yallop <yallop@gmail.com> wrote:

>
> Yes: record definitions are indeed generative in OCaml, unlike in Standard
> ML.
>