0005619: Uncuaght CType.Unify exception

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0005619

OCaml

OCaml general

public

2012-05-18 14:17

2012-05-25 07:22

Reporter

lpw25

Assigned To

garrigue

Priority

low

Severity

crash

Reproducibility

always

Status

closed

Resolution

fixed

Platform

OS Version

Product Version

Target Version

Fixed in Version

4.00.0+dev

Summary

0005619: Uncuaght CType.Unify exception

Description

Compiling the following code produces an uncaught CType.Unify exception:

  exception Bad_cast

  class type foo_t =
  object
    method foo: string
  end

  type 'a name =
      Foo: foo_t name
    | Int: int name

  class foo: foo_t =
  object(self)
    method foo = "foo"
    method cast: type a. a name -> a =
      function
          Foo -> (self :> foo_t)
        | _ -> ((raise Bad_cast) : a)
  end

I am using revision 12464 from the repository.

I know that this code is not valid. The original code used my "open types" extension, but I had to remove those bits to show that the bug was not in my extension.

The bug could be avoided in my original code by changing (self :> foo_t) to (self : #foo_t :> foo_t).

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No tags attached.

Attached Files

cast.ml [^] (295 bytes) 2012-05-18 14:17

Relationships

Notes
(0007462) garrigue (manager) 2012-05-25 07:22	Duplicating the environment for GADT pattern matching resulted in wrong detection of self-escape. Solved by not copying the argument to the dummy_method in subst.ml, under specific conditions. Fixed in trunk and 4.00, at revisions 12482 and 12483.

Issue History
Date Modified	Username	Field	Change
2012-05-18 14:17	lpw25	New Issue
2012-05-18 14:17	lpw25	File Added: cast.ml
2012-05-18 15:28	gasche	Status	new => acknowledged
2012-05-19 03:52	garrigue	Assigned To	=> garrigue
2012-05-19 03:52	garrigue	Status	acknowledged => assigned
2012-05-25 07:22	garrigue	Note Added: 0007462
2012-05-25 07:22	garrigue	Status	assigned => closed
2012-05-25 07:22	garrigue	Resolution	open => fixed
2012-05-25 07:22	garrigue	Fixed in Version	=> 4.00.0+dev