0004570: Confusing type error message with recursive modules

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Project

Category

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Date Submitted

Last Update

0004570

OCaml

OCaml general

public

2008-06-26 22:19

2012-08-06 18:26

Reporter

yallop

Assigned To

Priority

normal

Severity

minor

Reproducibility

always

Status

acknowledged

Resolution

open

Platform

OS Version

Product Version

3.10.2

Target Version

4.01.0+dev

Fixed in Version

Summary

0004570: Confusing type error message with recursive modules

Description

The following (wrong) code

  module rec M : sig type 'a s = 'a N.t end =
              struct type 'a s = 'a N.t end
         and N : sig type 'a t end =
              struct type t end

gives rise to the following confusing error message:

                 struct type 'a s = 'a N.t end
                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   Signature mismatch:
   Modules do not match:
     sig type 'a s = 'a N.t end
   is not included in
     sig type 'a s = 'a N.t end
   Type declarations do not match:
     type 'a s = 'a N.t
   is not included in
     type 'a s = 'a N.t

It'd be less surprising if the mismatch between the number of type parameters in the structure and signature declarations of N.t were reported instead.

Tags

recmod

Attached Files

Relationships

Notes
(0004596) doligez (manager) 2008-09-04 17:02	Strange, 3.10.0 gave a much better error message.

(0007913) xleroy (administrator) 2012-08-06 18:24	I've been sleeping on these PR for too long, and still have no idea how to address them. Unassigning them from myself.

Issue History
Date Modified	Username	Field	Change
2008-06-26 22:19	yallop	New Issue
2008-09-04 16:48	doligez	Assigned To	=> xleroy
2008-09-04 16:48	doligez	Status	new => acknowledged
2008-09-04 17:02	doligez	Note Added: 0004596
2012-07-11 15:50	doligez	Target Version	=> 4.01.0+dev
2012-07-29 18:02	frisch	Tag Attached: recmod
2012-07-31 13:36	doligez	Target Version	4.01.0+dev => 4.00.1+dev
2012-08-06 18:22	xleroy	Target Version	4.00.1+dev => 4.01.0+dev
2012-08-06 18:24	xleroy	Note Added: 0007913
2012-08-06 18:26	xleroy	Assigned To	xleroy =>