Clarify/Simplify - description of textNumberPattern with V, P
I am implementing dfdl:textNumberPattern characters V and E for Apache Daffodil. The DFDL Spec says (Section 13.6.1.1) It is a Schema Definition Error if any symbols other than "0", "1" through "9" or # are used in the vpinteger region of the pattern. Note that the vpitneger region of the pattern excludes the leading and/or trailing sign indicator characters which are the prefix and suffix. The prefix and suffix can contain any character except the special characters of the pattern language. Later in the section the spec has a number of detailed statements that are subsumed by the above I believe. - A pattern with a V symbol must not have @ or * symbols. - A pattern with P symbols must not have @ or E or * symbols. So those latter 2 statements could be omitted since @ and * are "special characters" so aren't allowed in the prefix/suffix, and per above stipulation can't be in the vpinteger region either. Can't we simplify and just say a pattern with V or P cannot have any special characters other than 0-9 and # ? Mike Beckerle Apache Daffodil PMC | daffodil.apache.org OGF DFDL Workgroup Co-Chair | www.ogf.org/ogf/doku.php/standards/dfdl/dfdl Owl Cyber Defense | www.owlcyberdefense.com
Hi Mike I've read through the section and I agree that there are some improvements that can be made. I think we can go further than you suggest too. Here's the syntax from spec Fig 4 ... vpinteger := pinteger | (vinteger exponent?) pinteger := ('P'* integer) | (integer 'P'* ) vinteger := ('V'? integer) | ('#'* 'V'? integer)| ('#'* '0'* 'V'? '0'* '0')| (integer 'V'?) integer := '#'* '0'* '0' Here are the bullets ... • A pattern with a V symbol must not have # symbols to the right of the V symbol. • A pattern with P symbols at the left end must not have # symbols . • A pattern with P symbols at the right end can have # symbols. • A pattern with a V symbol must not have @ or * symbols. • A pattern with P symbols must not have @ or E or * symbols. 1) I would question why we use 'V'? and 'P'* instead of 'V' and 'P' 'P'*. As written, it allows the V or P to be omitted entirely, but omission is already catered for by the number term (as '.' fraction is optional) 2) If 'V'? becomes 'V' then clause ('#'* 'V'? integer) is invalid as it contradicts bullet #1 as integer allows '#'. 3) Clause ('V'? integer) similarly, but it's redundant anyway as it is implied by the clause in 2) 4) Clause ('P'* integer) can be rewritten as ('P' 'P'* '0'* 0) which removes need for bullet #2 5) As you observe, bullets #3, #4 & #5 add nothing. I think we can rewrite the syntax as below and remove all the bullets. vpinteger := pinteger | (vinteger exponent?) pinteger := ('P' 'P'* '0'* '0') | (integer 'P'* 'P' ) vinteger := ('#'* '0'* 'V' '0'* '0') | (integer 'V') Note that I have avoided the obvious and more convenient use of 'X'+ because the + qualifier is not used elsewhere in Fig 4, I suspect to avoid confusion with the '+' symbol. I would also suggest that the exponent term is incorrect. Surely you need at least an 'E' or a '+' . exponent := ('E' | '+' | 'E+') '0'* '0' And what does the text " - special Characters" and " - quote" signify in Fig 4? Regards Steve Hanson IBM Integration, Hursley, UK Architect, IBM DFDL Co-Chair, OGF DFDL Working Group smh@uk.ibm.com<mailto:smh@uk.ibm.com> tel:+44-7717-378890 Note: I work Tuesday to Friday -----Original Message----- From: Mike Beckerle <mbeckerle@apache.org<mailto:Mike%20Beckerle%20%3cmbeckerle@apache.org%3e>> Reply-To: mbeckerle@apache.org<mailto:mbeckerle@apache.org> To: DFDL-WG <dfdl-wg@ogf.org<mailto:DFDL-WG%20%3cdfdl-wg@ogf.org%3e>> Subject: [EXTERNAL] [DFDL-WG] Clarify/Simplify - description of textNumberPattern with V, P Date: Thu, 22 Dec 2022 21:55:12 -0500 I am implementing dfdl: textNumberPattern characters V and E for Apache Daffodil. The DFDL Spec says (Section 13. 6. 1. 1) It is a Schema Definition Error if any symbols other than "0", "1" through "9" or # are used ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd I am implementing dfdl:textNumberPattern characters V and E for Apache Daffodil. The DFDL Spec says (Section 13.6.1.1) It is a Schema Definition Error if any symbols other than "0", "1" through "9" or # are used in the vpinteger region of the pattern. Note that the vpitneger region of the pattern excludes the leading and/or trailing sign indicator characters which are the prefix and suffix. The prefix and suffix can contain any character except the special characters of the pattern language. Later in the section the spec has a number of detailed statements that are subsumed by the above I believe. * A pattern with a V symbol must not have @ or * symbols. * A pattern with P symbols must not have @ or E or * symbols. So those latter 2 statements could be omitted since @ and * are "special characters" so aren't allowed in the prefix/suffix, and per above stipulation can't be in the vpinteger region either. Can't we simplify and just say a pattern with V or P cannot have any special characters other than 0-9 and # ? Mike Beckerle Apache Daffodil PMC | daffodil.apache.org<http://daffodil.apache.org/> OGF DFDL Workgroup Co-Chair | www.ogf.org/ogf/doku.php/standards/dfdl/dfdl<http://www.ogf.org/ogf/doku.php/standards/dfdl/dfdl> Owl Cyber Defense | www.owlcyberdefense.com<http://www.owlcyberdefense.com/> -- dfdl-wg mailing list dfdl-wg@lists.ogf.org<mailto:dfdl-wg@lists.ogf.org> https://lists.ogf.org/mailman/listinfo/dfdl-wg Unless otherwise stated above: IBM United Kingdom Limited Registered in England and Wales with number 741598 Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU
Erratum issue https://github.com/OpenGridForum/DFDL/issues/38 created - please review. Regards Steve Hanson IBM Integration, Hursley, UK Architect, IBM DFDL Co-Chair, OGF DFDL Working Group smh@uk.ibm.com<mailto:smh@uk.ibm.com> tel:+44-7717-378890 Note: I work Tuesday to Friday -----Original Message----- From: Steve Hanson <smh@uk.ibm.com<mailto:Steve%20Hanson%20%3csmh@uk.ibm.com%3e>> To: mbeckerle@apache.org<mailto:mbeckerle@apache.org>, DFDL-WG <dfdl-wg@ogf.org<mailto:DFDL-WG%20%3cdfdl-wg@ogf.org%3e>> Subject: Re: [EXTERNAL] [DFDL-WG] Clarify/Simplify - description of textNumberPattern with V, P Date: Wed, 04 Jan 2023 15:40:13 +0000 Hi Mike I've read through the section and I agree that there are some improvements that can be made. I think we can go further than you suggest too. Here's the syntax from spec Fig 4 ... vpinteger := pinteger | (vinteger exponent?) pinteger := ('P'* integer) | (integer 'P'* ) vinteger := ('V'? integer) | ('#'* 'V'? integer)| ('#'* '0'* 'V'? '0'* '0')| (integer 'V'?) integer := '#'* '0'* '0' Here are the bullets ... • A pattern with a V symbol must not have # symbols to the right of the V symbol. • A pattern with P symbols at the left end must not have # symbols . • A pattern with P symbols at the right end can have # symbols. • A pattern with a V symbol must not have @ or * symbols. • A pattern with P symbols must not have @ or E or * symbols. 1) I would question why we use 'V'? and 'P'* instead of 'V' and 'P' 'P'*. As written, it allows the V or P to be omitted entirely, but omission is already catered for by the number term (as '.' fraction is optional) 2) If 'V'? becomes 'V' then clause ('#'* 'V'? integer) is invalid as it contradicts bullet #1 as integer allows '#'. 3) Clause ('V'? integer) similarly, but it's redundant anyway as it is implied by the clause in 2) 4) Clause ('P'* integer) can be rewritten as ('P' 'P'* '0'* 0) which removes need for bullet #2 5) As you observe, bullets #3, #4 & #5 add nothing. I think we can rewrite the syntax as below and remove all the bullets. vpinteger := pinteger | (vinteger exponent?) pinteger := ('P' 'P'* '0'* '0') | (integer 'P'* 'P' ) vinteger := ('#'* '0'* 'V' '0'* '0') | (integer 'V') Note that I have avoided the obvious and more convenient use of 'X'+ because the + qualifier is not used elsewhere in Fig 4, I suspect to avoid confusion with the '+' symbol. I would also suggest that the exponent term is incorrect. Surely you need at least an 'E' or a '+' . exponent := ('E' | '+' | 'E+') '0'* '0' And what does the text " - special Characters" and " - quote" signify in Fig 4? Regards Steve Hanson IBM Integration, Hursley, UK Architect, IBM DFDL Co-Chair, OGF DFDL Working Group smh@uk.ibm.com<mailto:smh@uk.ibm.com> tel:+44-7717-378890 Note: I work Tuesday to Friday -----Original Message----- From: Mike Beckerle <mbeckerle@apache.org<mailto:Mike%20Beckerle%20%3cmbeckerle@apache.org%3e>> Reply-To: mbeckerle@apache.org<mailto:mbeckerle@apache.org> To: DFDL-WG <dfdl-wg@ogf.org<mailto:DFDL-WG%20%3cdfdl-wg@ogf.org%3e>> Subject: [EXTERNAL] [DFDL-WG] Clarify/Simplify - description of textNumberPattern with V, P Date: Thu, 22 Dec 2022 21:55:12 -0500 I am implementing dfdl: textNumberPattern characters V and E for Apache Daffodil. The DFDL Spec says (Section 13. 6. 1. 1) It is a Schema Definition Error if any symbols other than "0", "1" through "9" or # are used ZjQcmQRYFpfptBannerStart This Message Is From an External Sender This message came from outside your organization. ZjQcmQRYFpfptBannerEnd I am implementing dfdl:textNumberPattern characters V and E for Apache Daffodil. The DFDL Spec says (Section 13.6.1.1) It is a Schema Definition Error if any symbols other than "0", "1" through "9" or # are used in the vpinteger region of the pattern. Note that the vpitneger region of the pattern excludes the leading and/or trailing sign indicator characters which are the prefix and suffix. The prefix and suffix can contain any character except the special characters of the pattern language. Later in the section the spec has a number of detailed statements that are subsumed by the above I believe. * A pattern with a V symbol must not have @ or * symbols. * A pattern with P symbols must not have @ or E or * symbols. So those latter 2 statements could be omitted since @ and * are "special characters" so aren't allowed in the prefix/suffix, and per above stipulation can't be in the vpinteger region either. Can't we simplify and just say a pattern with V or P cannot have any special characters other than 0-9 and # ? Mike Beckerle Apache Daffodil PMC | daffodil.apache.org<http://daffodil.apache.org/> OGF DFDL Workgroup Co-Chair | www.ogf.org/ogf/doku.php/standards/dfdl/dfdl<http://www.ogf.org/ogf/doku.php/standards/dfdl/dfdl> Owl Cyber Defense | www.owlcyberdefense.com<http://www.owlcyberdefense.com/> -- dfdl-wg mailing list dfdl-wg@lists.ogf.org<mailto:dfdl-wg@lists.ogf.org> https://lists.ogf.org/mailman/listinfo/dfdl-wg Unless otherwise stated above: IBM United Kingdom Limited Registered in England and Wales with number 741598 Registered office: PO Box 41, North Harbour, Portsmouth, Hants. PO6 3AU
participants (2)
-
Mike Beckerle -
Steve Hanson