0005057: fatal typing error with local module + functor + polymorphic variant - MantisBT

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ID

Project

Category

View Status

Date Submitted

Last Update

0005057

OCaml

OCaml general

public

2010-05-20 14:47

2010-05-21 03:27

Reporter

ygrek

Assigned To

Priority

normal

Severity

minor

Reproducibility

always

Status

closed

Resolution

fixed

Platform

OS

OS Version

Product Version

3.11.2

Target Version

Fixed in Version

3.12.0+dev

Summary

0005057: fatal typing error with local module + functor + polymorphic variant

Description

$ cat bug.ml

module TT = struct
module IntSet = Set.Make(struct type t = int let compare = compare end)
end

let () =
  let f flag =
    let module T = TT in
    let _ = match flag with `A -> 0 | `B r -> r in
    let _ = match flag with `A -> T.IntSet.mem | `B r -> r in
    ()
  in
  f ()

$ ocamlc -c bug.ml
Fatal error: exception Ctype.Unify(_, _)

$ ocamlc -version
3.11.2

Additional Information

This is a minimized example, originally occurred in real sensible code.
Also reported to fail in 3.12.0+dev17

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No tags attached.

Relationships

Notes
(0005478) garrigue (manager) 2010-05-21 03:27	The correct code should be "f `A" :-) There was a bug in the handling of levels inside polymorphic variant fields. This is now fixed for 3.12. Note that your report helped discover a more serious problem, where the following code was wrongly accepted. Thank you very much. let f flag = let module T = Set.Make(struct type t = int let compare = compare end) in let _ = match flag with `A -> 0 \| `B r -> r in let _ = match flag with `A -> T.mem \| `B r -> r in ()

Issue History
Date Modified	Username	Field	Change
2010-05-20 14:47	ygrek	New Issue
2010-05-21 03:27	garrigue	Note Added: 0005478
2010-05-21 03:27	garrigue	Status	new => closed
2010-05-21 03:27	garrigue	Resolution	open => fixed
2010-05-21 03:27	garrigue	Fixed in Version	=> 3.12.0+dev

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