Original bug ID: 3394
Reporter: administrator
Status: closed
Resolution: won't fix
Priority: normal
Severity: feature
Category: ~DO NOT USE (was: OCaml general)

Bug description

From: ethan.aubin@pobox.com

Hi, I would like to use let rec for the recursive definition of
object values.
Something along the lines of:

class number_stream (first : int) (next : number_stream) = object
val v = first
val next = next
end

let rec ones = new number_stream 1 ones
in ones;;

Unfortunately, with the call-by-value semantics of the language, the
above definition is ill-founded. There is no concept of "uninitialized
object", like is used for datatypes in recursive value definitions.

There is a workaround:

class number_stream (first : int) (next : number_stream Lazy.t) =
object
method v = first
method next = Lazy.force next
end

let rec ones = lazy (new number_stream 1 ones)
let ones = Lazy.force ones

Jacques