Re: [netmod] WG LC draft-ietf-netmod-module-tags-02 - 10/2/18 - 10/16/18

[Christian Hopps <[e-mail]>]

> On Oct 16, 2018, at 7:39 PM, Andy Bierman <[e-mail]> wrote:
> 
> 
> 
> On Tue, Oct 16, 2018 at 3:15 PM, Christian Hopps <[e-mail]> wrote:
> 
> Andy Bierman <[e-mail]> writes:
> 
> This draft needs to define the module-tag encoding wrt/
>    - valid characters (e.g., some subset of UTF-8)
>    - min/max length (e.g., implementation MUST support at least 64 chars
> and can support larger)
> 
> I'm looking for suggestions on how to do this subset. We had intended to allow for as wide as possible content; however, I think disallowing tabs, newlines, carriage returns is more than reasonable. Has a type like this already been standardized or is there an example available somewhere?
> 
> I suppose yang-identifier type is too restrictive so I will agree that restricting whitespace and colon chars
> is probably good enough 


I'm going to use:

  typedef tag {
    type string {
      pattern '[a-zA-Z_][a-zA-Z0-9\-_]*:[\S ]+';
      length "1..max";
    }
    description
      "A tag value is composed of a standard prefix followed
       by any string value that does not include carriage return,
       form-feed, newline or tab characters."
  }

I left in space -- lot's of people in the non-unix world use spaces.

Thanks,
Chris.