"ocaml_beginners"::[] compile-error "illegal permutation of structure fields"

[Andreas Romeyke]

Hello,

by compiling a module I got following error:

---- 8>< --- 8>< --- 8>< ----
The implementation speedseg.ml
does not match the interface (inferred signature):
Module type declarations do not match:
  module type Speedseg =
    sig
      type segm_t = Background of int | Foreground of int | Unsegmented
      type bbox_t = { x0 : int; y0 : int; x1 : int; y1 : int; }
      type 'a tree_t = Leaf of 'a | Node of 'a tree_t * 'a tree_t
      exception SegmentationError of string
      val xsort : ('a * bbox_t) list -> ('a * bbox_t) list
      val ysort : ('a * bbox_t) list -> ('a * bbox_t) list
      val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
list
      val segment_page :
        Sdlvideo.surface -> Sdlvideo.color -> (segm_t * bbox_t) tree_t
      val draw_image :
        (segm_t * bbox_t) tree_t ->
        Sdlvideo.surface -> string -> (segm_t * bbox_t) list
      val intersection_and_complement :
        bbox_t -> bbox_t -> bool * bbox_t list * bbox_t list
      val test_if_connected : bbox_t -> bbox_t -> bool
      val filter_all_connected_bboxes :
        segm_t * bbox_t ->
        (segm_t * bbox_t) list ->
        (segm_t * bbox_t) list * (segm_t * bbox_t) list
      val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
list
    end
does not match
  module type Speedseg =
    sig
      type segm_t = Background of int | Foreground of int | Unsegmented
      type bbox_t = { x0 : int; y0 : int; x1 : int; y1 : int; }
      type 'a tree_t = Leaf of 'a | Node of 'a tree_t * 'a tree_t
      exception SegmentationError of string
      val xsort : ('a * bbox_t) list -> ('a * bbox_t) list
      val ysort : ('a * bbox_t) list -> ('a * bbox_t) list
      val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
list
      val segment_page :
        Sdlvideo.surface -> Sdlvideo.color -> (segm_t * bbox_t) tree_t
      val draw_image :
        (segm_t * bbox_t) tree_t ->
        Sdlvideo.surface -> string -> (segm_t * bbox_t) list
      val intersection_and_complement :
        bbox_t -> bbox_t -> bool * bbox_t list * bbox_t list
      val test_if_connected : bbox_t -> bbox_t -> bool
      val filter_all_connected_bboxes :
        segm_t * bbox_t ->
        (segm_t * bbox_t) list ->
        (segm_t * bbox_t) list * (segm_t * bbox_t) list
      val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
list
    end
Illegal permutation of structure fields
---- ><8 --- ><8 --- ><8 ----

If I comment out the last entry (compress_bboxes) then it will compile
sucessfully. The problem is that there is no difference between both
signatures. The signature is equivalent to the signature created with
"ocamlc -i speedseg.ml"

Could you help me to understand this error-message, please?

PS.: I am using ocaml in version 3.10.2 (Debian Lenny)

--
Andreas Romeyke
- Abteilung Blindenschrift -
Deutsche Zentralbücherei für Blinde zu Leipzig (DZB)
Gustav-Adolf-Straße 7, 04105 Leipzig
Tel: [phone]-..., Fax: [phone]
Internet: www.dzb.de
E-Mail: andreas.romeyke@...


[Non-text portions of this message have been removed]

[Hugo Ferreira]

Hi Andreas,

Looking at the first declaration I see:

 >       val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
 > list
....
 >       val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
 > list

Two functions with the same parameters?
If this is not an error try using different names
for these functions.

HTH,
Hugo F.



Romeyke, Andreas wrote:

> Hello,
>
> by compiling a module I got following error:
>
> ---- 8>< --- 8>< --- 8>< ----
> The implementation speedseg.ml
> does not match the interface (inferred signature):
> Module type declarations do not match:
>   module type Speedseg =
>     sig
>       type segm_t = Background of int | Foreground of int | Unsegmented
>       type bbox_t = { x0 : int; y0 : int; x1 : int; y1 : int; }
>       type 'a tree_t = Leaf of 'a | Node of 'a tree_t * 'a tree_t
>       exception SegmentationError of string
>       val xsort : ('a * bbox_t) list -> ('a * bbox_t) list
>       val ysort : ('a * bbox_t) list -> ('a * bbox_t) list
>       val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
> list
>       val segment_page :
>         Sdlvideo.surface -> Sdlvideo.color -> (segm_t * bbox_t) tree_t
>       val draw_image :
>         (segm_t * bbox_t) tree_t ->
>         Sdlvideo.surface -> string -> (segm_t * bbox_t) list
>       val intersection_and_complement :
>         bbox_t -> bbox_t -> bool * bbox_t list * bbox_t list
>       val test_if_connected : bbox_t -> bbox_t -> bool
>       val filter_all_connected_bboxes :
>         segm_t * bbox_t ->
>         (segm_t * bbox_t) list ->
>         (segm_t * bbox_t) list * (segm_t * bbox_t) list
>       val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
> list
>     end
> does not match
>   module type Speedseg =
>     sig
>       type segm_t = Background of int | Foreground of int | Unsegmented
>       type bbox_t = { x0 : int; y0 : int; x1 : int; y1 : int; }
>       type 'a tree_t = Leaf of 'a | Node of 'a tree_t * 'a tree_t
>       exception SegmentationError of string
>       val xsort : ('a * bbox_t) list -> ('a * bbox_t) list
>       val ysort : ('a * bbox_t) list -> ('a * bbox_t) list
>       val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
> list
>       val segment_page :
>         Sdlvideo.surface -> Sdlvideo.color -> (segm_t * bbox_t) tree_t
>       val draw_image :
>         (segm_t * bbox_t) tree_t ->
>         Sdlvideo.surface -> string -> (segm_t * bbox_t) list
>       val intersection_and_complement :
>         bbox_t -> bbox_t -> bool * bbox_t list * bbox_t list
>       val test_if_connected : bbox_t -> bbox_t -> bool
>       val filter_all_connected_bboxes :
>         segm_t * bbox_t ->
>         (segm_t * bbox_t) list ->
>         (segm_t * bbox_t) list * (segm_t * bbox_t) list
>       val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
> list
>     end
> Illegal permutation of structure fields
> ---- ><8 --- ><8 --- ><8 ----
>
> If I comment out the last entry (compress_bboxes) then it will compile
> sucessfully. The problem is that there is no difference between both
> signatures. The signature is equivalent to the signature created with
> "ocamlc -i speedseg.ml"
>
> Could you help me to understand this error-message, please?
>
> PS.: I am using ocaml in version 3.10.2 (Debian Lenny)
>

[artemis01]

Hi Andreas and Hugo,

Hugo Ferreira a écrit :

>  
>
> Hi Andreas,
>
> Looking at the first declaration I see:
>
>  > val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
>  > list
> ....
>  > val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
>  > list
>
> Two functions with the same parameters?
> If this is not an error try using different names
> for these functions.

That is what I would have suggested, and indeed, if I try to compile:

---------------
module type Foo = sig
   val f : int -> int
   val f : int -> int
end;;

module Bar : Foo = struct
   let f x = x
   let f x = x+1
end;;
---------------

I get the same error. But this works in a top-level. We can then do :

---------------
# Bar.f 3;;
- : int = 4
---------------

Does anyone knows why ?
--
Chantal KELLER

[Andreas Romeyke]

Hello,

Am Montag, den 16.11.2009, 13:36 +0000 schrieb Hugo Ferreira:

>
> Looking at the first declaration I see:
>
> > val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
> > list
> ....
> > val compress_bboxes : (segm_t * bbox_t) list -> (segm_t * bbox_t)
> > list
>
> Two functions with the same parameters?
> If this is not an error try using different names
> for these functions.

Thanks, that was the reason, I had 2 signatures used... Thanks :)

Bye Andreas

--
Andreas Romeyke
- Abteilung Blindenschrift -
Deutsche Zentralbücherei für Blinde zu Leipzig (DZB)
Gustav-Adolf-Straße 7, 04105 Leipzig
Tel: [phone]-..., Fax: [phone]
Internet: www.dzb.de
E-Mail: andreas.romeyke@...


[Non-text portions of this message have been removed]