IMAPEXT A. Melnikov Internet-Draft Isode Limited Intended status: Standards Track February 14, 2009 Expires: August 18, 2009 Additional collation algorithms for use in IMAP and Sieve draft-ietf-morg-collations-00 Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on August 18, 2009. Copyright Notice Copyright (c) 2009 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Abstract This document defines extra collation that were found useful when searching for text in email messages. Melnikov Expires August 18, 2009 [Page 1] Internet-Draft Collation Algorithms February 2009 Note A revised version of this draft document will be submitted to the RFC editor as a Proposed Standard for the Internet Community. Discussion and suggestions for improvement are requested, and should be sent to morg@ietf.org. Table of Contents 1. Conventions used in this document . . . . . . . . . . . . . . 3 2. ASCII Signed Numeric Collation Description . . . . . . . . . 3 2.1. ASCII Signed Numeric Collation Registration . . . . . . . . . 4 3. ASCII Punctuation Ignore Numeric Collation Description . . . 4 3.1. ASCII Punctuation Ignore Numeric Collation Registration . . . 5 4. Other Collations . . . . . . . . . . . . . . . . . . . . . . 5 5. Formal Syntax . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations . . . . . . . . . . . . . . . . . . . 5 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 6 9.1. Normative References . . . . . . . . . . . . . . . . . . . . 6 9.2. Informative References . . . . . . . . . . . . . . . . . . . 6 Author's Address . . . . . . . . . . . . . . . . . . . . . . 6 Melnikov Expires August 18, 2009 [Page 2] Internet-Draft Collation Algorithms February 2009 1. Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [Kwds]. 2. ASCII Signed Numeric Collation Description The "i;ascii-signed-numeric" collation is a simple collation intended for use with arbitrarily-sized, signed decimal integer numbers stored as octet strings. US-ASCII digits (0x30 to 0x39) represent digits of the numbers. The numbers can have an arbitrary number of leading US- ASCII whitespace characters (0x20), optionally followed by the sign ("+", "-") and then by digits of the number. If the "+" sign is omitted, the number is considered to be positive. Before converting from string to integer, all leading whitespace characters are removed. If no "+" or "-" character is found, "+" is then prepended to the string. And finally, the input string is truncated at the first non-digit character, not counting the "+"/"-" prefix. All input is valid for this collation; strings that do not start (after whitespace removal) with a "+", "-" or a digit represent positive infinity. The collation supports equality and ordering, but does not support the substring operation. The equality operation returns "match" if the two strings represent the same number (i.e., leading whitespaces, zeroes and trailing non- digits are disregarded), and "no-match" if the two strings represent different numbers. The ordering operation returns "less" if the first string represents a smaller number than the second, "equal" if they represent the same number, and "greater" if the first string represents a larger number than the second. Some examples: " -500" is less than "-90", " 0" is less than "1M", and "1" is less than "4294967298". "4294967298", "04294967298", and "4294967298b" are all equal. "04294967298" is less than "". "+", "-", "", "x", and "y" are equal. Melnikov Expires August 18, 2009 [Page 3] Internet-Draft Collation Algorithms February 2009 2.1. ASCII Signed Numeric Collation Registration i;ascii-signed-numeric ASCII Signed Numeric equality order RFC XXXX IETF alexey.melnikov@isode.com 3. ASCII Punctuation Ignore Numeric Collation Description The "i;ascii-punc-ignore-numeric" collation is a collation intended for use with arbitrarily-sized, unsigned decimal integer numbers stored as octet strings. US-ASCII digits (0x30 to 0x39) represent digits of the numbers. Any digit of such numbers can be followed or preceeded by any number of the following US-ASCII characters, which are ignored for the purpose of comparison: " " (0x20), "-", "+", ",", ";", ".". [[anchor5: The list of characters to ignore is to be discussed.]] Before converting from string to integer, all characters to be ignored are removed from the string. After that, the input string is truncated at the first non-digit character. All input is valid for this collation; strings that do not start (after removal of all characters to ignore) with a digit represent positive infinity. The collation supports equality and ordering, but does not support the substring operation. The equality operation returns "match" if the two strings represent the same number (i.e., leading whitespaces, zeroes and trailing non- digits are disregarded), and "no-match" if the two strings represent different numbers. The ordering operation returns "less" if the first string represents a smaller number than the second, "equal" if they represent the same number, and "greater" if the first string represents a larger number than the second. Some examples: "+1-500" is less than "2 50.0", " 0" is less than "1M", and "1" is less than "4294967298". "4294967298", "04294967298", and "4294967298b" are all equal. "04294967298" is less than "". "+", "-", "", "x", and "y" are equal. Melnikov Expires August 18, 2009 [Page 4] Internet-Draft Collation Algorithms February 2009 3.1. ASCII Punctuation Ignore Numeric Collation Registration i;ascii-punc-ignore-numeric ASCII Punctuation Ignore Numeric equality order RFC XXXX IETF alexey.melnikov@isode.com 4. Other Collations [[anchor8: Other collations to consider: case preserving version of i;unicode-casemap defined in RFC 5051.]] 5. Formal Syntax The following syntax specification uses the augmented Backus-Naur Form (BNF) as described in [ABNF]. Terms not defined here are taken from [ABNF]. ascii-signed-numeric = *SP [("-" / "+")] 1*DIGIT ; This production defines valid string prefixes punc-ignore-unsigned-numeric = *punctuation DIGIT *(punctuation / DIGIT) ; This production defines valid string prefixes punctuation = SP / "+" / "-" / "." / "," / ";" 6. Security Considerations [[anchor9: TBD.]] 7. IANA Considerations TBD. Melnikov Expires August 18, 2009 [Page 5] Internet-Draft Collation Algorithms February 2009 8. Acknowledgements TBD. 9. References 9.1. Normative References [ABNF] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax Specifications: ABNF", RFC 5234, January 2008. [Kwds] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [RFC4790] Newman, C., Duerst, M., and A. Gulbrandsen, "Internet Application Protocol Collation Registry", RFC 4790, March 2007. 9.2. Informative References [RFC3501] Crispin, M., "INTERNET MESSAGE ACCESS PROTOCOL - VERSION 4rev1", RFC 3501, March 2003. Author's Address Alexey Melnikov Isode Limited 5 Castle Business Village 36 Station Road Hampton, Middlesex TW12 2BX UK Email: Alexey.Melnikov@isode.com URI: http://www.melnikov.ca/ Melnikov Expires August 18, 2009 [Page 6]