Copying fields in OCaml

Question

Hi Guys,

I have a very basic question regarding OCaml records. Suppose I have a record defined:

type r = {a:int;b:int;c:int}
let x = {a=3;b=8;c=2}

Now, suppose I want to create a new record which has all fields equal to x but which has c=4. I could write:

let y = {a=3;b=8;c=4}

but this is annoying because there's not need to re-write a=3 and b=8. I could also write:

let y = {a=x.a;b=x.b;c=4}

but this is still not good if the record has many fields. Is there any way of writing something like:

let y = {x with c=4}

or something of the sort?

Thanks a lot for any help.

All the best, Surikator.

Answer 1

yeah, and that's the exact syntax.

let y = {x with c=4}