From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Delivered-To: caml-list@yquem.inria.fr Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by yquem.inria.fr (Postfix) with ESMTP id 87E51BBFA for ; Mon, 20 Jun 2005 17:20:41 +0200 (CEST) Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id j5KFKf67004740 for ; Mon, 20 Jun 2005 17:20:41 +0200 Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id RAA14370 for ; Mon, 20 Jun 2005 17:20:40 +0200 (MET DST) Received: from shiva.jussieu.fr (shiva.jussieu.fr [134.157.0.129]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id j5KFKe0D004736 for ; Mon, 20 Jun 2005 17:20:40 +0200 Received: from liafa1.liafa.jussieu.fr (liafa1.liafa.jussieu.fr [132.227.93.1]) by shiva.jussieu.fr (8.12.11/jtpda-5.4) with ESMTP id j5KFKerm077464 ; Mon, 20 Jun 2005 17:20:40 +0200 (CEST) X-Ids: 168 Received: from [132.227.81.31] ([132.227.81.31]) by liafa1.liafa.jussieu.fr (8.12.2/jtpda-5.3.2) with ESMTP id j5KFKduF010922 ; Mon, 20 Jun 2005 17:20:39 +0200 (CEST) Mime-Version: 1.0 (Apple Message framework v730) Message-Id: Content-Type: multipart/signed; micalg=sha1; boundary=Apple-Mail-1--760278718; protocol="application/pkcs7-signature" To: caml-list@inria.fr Subject: signature and 'a generic types From: Damien Bobillot Date: Mon, 20 Jun 2005 17:20:40 +0200 X-Mailer: Apple Mail (2.730) X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-1.7.2 (shiva.jussieu.fr [134.157.0.168]); Mon, 20 Jun 2005 17:20:40 +0200 (CEST) X-Antivirus: scanned by sophie at shiva.jussieu.fr X-Miltered: at nez-perce with ID 42B6DEC9.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Miltered: at nez-perce with ID 42B6DEC8.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Miltered: at shiva.jussieu.fr with ID 42B6DEC8.001 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; damien:01 damien:01 flowed:01 sig:01 val:01 func:01 struct:01 func:01 subtype:01 ocamlc:01 val:01 sig:01 struct:01 ocamlc:01 subtype:01 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on yquem.inria.fr X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.2 X-Spam-Level: --Apple-Mail-1--760278718 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Hello, Look at the following code : module Module : (sig val func : 'a -> 'b end) = struct let func a = a end Here Module.func's type is 'a -> 'a. According to me 'a -> 'a is a subtype of 'a -> 'b, it's 'a -> 'b with 'a = 'b. Nevertheless ocamlc give the following error : Values do not match: val func : 'a -> 'a is not included in val func : 'a -> 'b Why ? I also try to use the reverse match : module Module : (sig val func : 'a -> 'a end) = struct let l = ref [] let func a = List.assoc a !l end Where Module.func is of type 'a -> 'b. Ocamlc also give me an error, but I completely understand it here : 'a -> 'b is really not a subtype of 'a -> 'a. In this case I also don't understand why neither " 'a -> 'b is included in 'a -> 'a " nor " 'a -> 'a is included in 'a -> 'b " are true. To my mind, one should be true. Is it a caml limitation/bug, or am I wrong somewhere ? -- Damien Bobillot --Apple-Mail-1--760278718 Content-Transfer-Encoding: base64 Content-Type: application/pkcs7-signature; name=smime.p7s Content-Disposition: attachment; filename=smime.p7s MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIGIjCCAtsw ggJEoAMCAQICAw54xzANBgkqhkiG9w0BAQQFADBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhh d3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVt YWlsIElzc3VpbmcgQ0EwHhcNMDUwNDEzMTc1MTAxWhcNMDYwNDEzMTc1MTAxWjBJMR8wHQYDVQQD ExZUaGF3dGUgRnJlZW1haWwgTWVtYmVyMSYwJAYJKoZIhvcNAQkBFhdkYW1pZW4uYm9iaWxsb3RA bTR4Lm9yZzCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAJ1TOYBqwJ42s0Fzz56jY1p0 fplGyikFgoNEUKGnOpqt4vpeoqUppAnORt2yvdQJxfIkhsWkrD/diiPS7MTF73wcxlSJtqYzVzPK G/2WDm6dBinuWCIyWYFhtGedyxbap3kJW44H7cL7HUVVxZ0JhOIOTsjCoEzaeKnML7bctbIJeXEE lErfbDv2jA1PDG1ru5dx+Q+AmbexX92ygnntE6aX3QZLSbhrytg4yCRdV8cOyQ9eFruZBI42RJv3 nJXevjUOr4n+y/7bzijAJj4BFyUU+dllvj6bmk5brnUXheCSOD0Ci20dqGNC1MyJ43b6MoIrbW7j JwYIv12D6KuWoaUCAwEAAaM0MDIwIgYDVR0RBBswGYEXZGFtaWVuLmJvYmlsbG90QG00eC5vcmcw DAYDVR0TAQH/BAIwADANBgkqhkiG9w0BAQQFAAOBgQB0u5b6wgwsbcyzDHJTzshlCn4gshxWtU/1 mH77gBCpsY8L554YV4/Tvm1PzmDzErm++drQf5HMy8sEFjmwLvNfBP0BqtkSqsdRFGR4wHzTjMhS EW5LgmlaccqBQzqQrANtzglgBVbtmBDAV92qHjQslwHK4FohCRRzGl4DLQmqBDCCAz8wggKooAMC AQICAQ0wDQYJKoZIhvcNAQEFBQAwgdExCzAJBgNVBAYTAlpBMRUwEwYDVQQIEwxXZXN0ZXJuIENh cGUxEjAQBgNVBAcTCUNhcGUgVG93bjEaMBgGA1UEChMRVGhhd3RlIENvbnN1bHRpbmcxKDAmBgNV BAsTH0NlcnRpZmljYXRpb24gU2VydmljZXMgRGl2aXNpb24xJDAiBgNVBAMTG1RoYXd0ZSBQZXJz b25hbCBGcmVlbWFpbCBDQTErMCkGCSqGSIb3DQEJARYccGVyc29uYWwtZnJlZW1haWxAdGhhd3Rl LmNvbTAeFw0wMzA3MTcwMDAwMDBaFw0xMzA3MTYyMzU5NTlaMGIxCzAJBgNVBAYTAlpBMSUwIwYD VQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29u YWwgRnJlZW1haWwgSXNzdWluZyBDQTCBnzANBgkqhkiG9w0BAQEFAAOBjQAwgYkCgYEAxKY8VXNV +065yplaHmjAdQRwnd/p/6Me7L3N9VvyGna9fww6YfK/Uc4B1OVQCjDXAmNaLIkVcI7dyfArhVqq P3FWy688Cwfn8R+RNiQqE88r1fOCdz0Dviv+uxg+B79AgAJk16emu59l0cUqVIUPSAR/p7bRPGEE QB5kGXJgt/sCAwEAAaOBlDCBkTASBgNVHRMBAf8ECDAGAQH/AgEAMEMGA1UdHwQ8MDowOKA2oDSG Mmh0dHA6Ly9jcmwudGhhd3RlLmNvbS9UaGF3dGVQZXJzb25hbEZyZWVtYWlsQ0EuY3JsMAsGA1Ud DwQEAwIBBjApBgNVHREEIjAgpB4wHDEaMBgGA1UEAxMRUHJpdmF0ZUxhYmVsMi0xMzgwDQYJKoZI hvcNAQEFBQADgYEASIzRUIPqCy7MDaNmrGcPf6+svsIXoUOWlJ1/TCG4+DYfqi2fNi/A9BxQIJNw PP2t4WFiw9k6GX6EsZkbAMUaC4J0niVQlGLH2ydxVyWN3amcOY6MIE9lX5Xa9/eH1sYITq726jTl EBpbNU1341YheILcIRk13iSx0x1G/11fZU8xggLnMIIC4wIBATBpMGIxCzAJBgNVBAYTAlpBMSUw IwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVy c29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIDDnjHMAkGBSsOAwIaBQCgggFTMBgGCSqGSIb3DQEJ AzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTA1MDYyMDE1MjA0MVowIwYJKoZIhvcNAQkE MRYEFIyp5/C8rbptlFsardD4Ik6sl0VoMHgGCSsGAQQBgjcQBDFrMGkwYjELMAkGA1UEBhMCWkEx JTAjBgNVBAoTHFRoYXd0ZSBDb25zdWx0aW5nIChQdHkpIEx0ZC4xLDAqBgNVBAMTI1RoYXd0ZSBQ ZXJzb25hbCBGcmVlbWFpbCBJc3N1aW5nIENBAgMOeMcwegYLKoZIhvcNAQkQAgsxa6BpMGIxCzAJ BgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQD EyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQIDDnjHMA0GCSqGSIb3DQEBAQUA BIIBAAE6oZfLZWFT/63X4u3KhSEjBIjK8bFSBL+yvhQ82c07Z0TU5gYZnnv42zCpvAchhRVEVLCQ ehRvlVDjCoJe+Tmx+m/7Dqb42IGSix2KcGTYHamqgBB0ylYKwh7b69h5uPA1V0/uJk60j0wYbtF6 iLaQBI82mZToOS8hWhFNO23kirOOZysdA7YNcspxkB6ZJ4FDwXh7o+K0YAqu65kcLGkYvUaTGbU2 HWY7EeN/0lmlltYTozOggekACJy+faZt1vcJYRRrt3DYinJ94v4D1dsVRTAcugRG7fvduhegNT6N 7M5f8xFQdW31GIQqtuJ6crJ487ct6Nh8WGtc6y9dsH4AAAAAAAA= --Apple-Mail-1--760278718--