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

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.

> …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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