Original bug ID: 1377
Reporter: administrator
Status: closed
Resolution: fixed
Priority: normal
Severity: minor
Category: ~DO NOT USE (was: OCaml general)

Bug description

Hi,

While ICFPing, I came upon some strange typing error messages.

The first one is :

class type ct = object
method m : l:int -> ct
end

let rec f (o : ct) =
let rec g o =
let x = o#m 1 in
g x in
g o

which is well typed accorded to caml if I remove the l label. Here is
the error I got:

This expression has type ct = < m : l:int -> ct > as 'a
but is here used with type 'a

The second one is ill-typed and get the same error message:

class type ct = object
method m : l:int -> int
end

let rec f (o : ct) =
let rec g o =
let x = o#m 1 in
g x in
g o

If I remove the label I got a stranger error:

This expression has type ct = < m : int -> int > as 'a
but is here used with type 'a
Type int is not compatible with type ct = 'a

Can someone explain that?

--
Dimitri Ara