Re: [netmod] [Editorial Errata Reported] RFC7950 (5642)

Andy Bierman <andy@yumaworks.com> wrote:
> On Thu, Feb 21, 2019 at 10:07 AM Peter Loborg <peter.loborg@ericsson.com>
> wrote:
> 
> >
> >
> > Your example is fine – but the gammar is ch14 specifies something
> > different:
> >
> >
> >
> > enum-stmt           = enum-keyword sep string optsep
> >
> >                          (";" /
> >
> >                           "{" stmtsep
> >
> >                               ;; these stmts can appear in any order
> >
> >                               *if-feature-stmt
> >
> >                               [value-stmt]
> >
> >                               [status-stmt]
> >
> >                               [description-stmt]
> >
> >                               [reference-stmt]
> >
> >                            "}") stmtsep
> >
> >
> >
> > It clearly states  string, not quoted-string. These two have the following
> > rules:
> >
> >
> >
> > quoted-string       = (DQUOTE string DQUOTE) / (SQUOTE string SQUOTE)
> >
> >
> >
> > string              = < an unquoted string, as returned by >
> >
> >                          < the scanner, that matches the rule >
> >
> >                          < yang-string >
> >
> >
> >
> 
> 
> The text in 9.6.4 is correct.
> The ABNF is wrong.

No, the ABNF is correct.  The ABNF doens't handle concatenation etc.
The idea is that the scanner handles quotes and concatenation and
returns a "string".

/martin

> 
> 
> 
> > …and in 6.1.3 we can read that:
> >
> >    An unquoted string is any sequence of characters that does not
> >
> >    contain any space, tab, carriage return, or line feed characters, a
> >
> >    single or double quote character, a semicolon (";"), braces ("{" or
> >
> >    "}"), or comment sequences ("//", "/*", or "*/").
> >
> >
> >
> >    Note that any keyword can legally appear as an unquoted string.
> >
> >
> >
> > Since the section so clearly writes about single quoted strings and double
> > quoted strings, there can unfortunately be no interpretation that would
> > allow “identifier” to be called an unquoted string – even though it follows
> > the rules about limited character contents.
> >
> >
> >
> > Hence – this is not a matter of opinion – it’s a matter of reading what’s
> > actually written in the RFC.
> >
> >
> >
> > But on the subject of opinion…
> >
> >
> >
> >       enum "This is also legal";   // should definitely always be illegal
> >
> >
> >
> > …as we cannot create a language binding to enum constructs in any major
> > programming languages.
> >
> >
> >
> 
> There are many aspects of YANG that do not map directly to programming
> languages,
> such as allowing '.' in identifiers.
> 
> 
> 
> > Br,
> >
> > Peter
> >
> 
> 
> Andy
> 
> 
> >
> >
> >
> >
> > *From:* Andy Bierman <andy@yumaworks.com>
> > *Sent:* den 21 februari 2019 18:45
> > *To:* Martin Bjorklund <mbj@tail-f.com>
> > *Cc:* RFC Editor <rfc-editor@rfc-editor.org>; Ignas Bagdonas <
> > ibagdona@gmail.com>; NetMod WG <netmod@ietf.org>; Peter Loborg <
> > peter.loborg@ericsson.com>; Warren Kumari <warren@kumari.net>
> > *Subject:* Re: [netmod] [Editorial Errata Reported] RFC7950 (5642)
> >
> >
> >
> >
> >
> >
> >
> > On Thu, Feb 21, 2019 at 8:53 AM Martin Bjorklund <mbj@tail-f.com> wrote:
> >
> > RFC Errata System <rfc-editor@rfc-editor.org> wrote:
> > > The following errata report has been submitted for RFC7950,
> > > "The YANG 1.1 Data Modeling Language".
> > >
> > > --------------------------------------
> > > You may review the report below and at:
> > > http://www.rfc-editor.org/errata/eid5642
> > >
> > > --------------------------------------
> > > Type: Editorial
> > > Reported by: Peter Loborg <peter.loborg@ericsson.com>
> > >
> > > Section: 9.6.4
> > >
> > > Original Text
> > > -------------
> > > It takes as an argument a string that is the assigned name.
> > >
> > > Corrected Text
> > > --------------
> > > It takes as an argument an unquoted string that is the assigned name.
> >
> > This is not correct.  The enum argument is not different from any
> > other keyword's arguments in YANG.  See e.g. the example in 9.12.4:
> >
> >        type enumeration {
> >          enum "unbounded";
> >        }
> >
> > The following is also legal:
> >
> >          enum "unb" + 'ounded';
> >
> >
> >
> >
> >
> >   enum "This is also legal";
> >
> >
> >
> > 9.6.4.  The "enum" Statement
> >
> >
> >
> >    The "enum" statement, which is a substatement to the "type"
> >
> >    statement, MUST be present if the type is "enumeration".  It is
> >
> >    repeatedly used to specify each assigned name of an enumeration type.
> >
> >    It takes as an argument a string that is the assigned name.  *The*
> >
> > *   string MUST NOT be zero-length and MUST NOT have any leading or*
> >
> > *   trailing whitespace characters* (any Unicode character with the
> >
> >    "White_Space" property).  The use of Unicode control codes SHOULD be
> >
> >    avoided.
> >
> >
> >
> >
> >
> > This errata should be rejected.
> >
> >
> >
> > /martin
> >
> >
> >
> >
> >
> > Andy
> >
> >
> >
> >
> > >
> > > Notes
> > > -----
> > > Readers are not beeing made aware that careful reading of section 6.1.3
> > and the detailed definition of string in section 14 must be consulted.
> > > For comming versions of this RFC it would be preferable to use a more
> > specialized grammar token for these cases (e.g. unquoted-string).
> > >
> > > Instructions:
> > > -------------
> > > This erratum is currently posted as "Reported". If necessary, please
> > > use "Reply All" to discuss whether it should be verified or
> > > rejected. When a decision is reached, the verifying party
> > > can log in to change the status and edit the report, if necessary.
> > >
> > > --------------------------------------
> > > RFC7950 (draft-ietf-netmod-rfc6020bis-14)
> > > --------------------------------------
> > > Title               : The YANG 1.1 Data Modeling Language
> > > Publication Date    : August 2016
> > > Author(s)           : M. Bjorklund, Ed.
> > > Category            : PROPOSED STANDARD
> > > Source              : Network Modeling
> > > Area                : Operations and Management
> > > Stream              : IETF
> > > Verifying Party     : IESG
> > >
> >
> > _______________________________________________
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> > netmod@ietf.org
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> >
> >