Charter changes and a possible new direction

John C Klensin klensin at jck.com
Wed Jan 14 12:19:32 CET 2009



--On Wednesday, 14 January, 2009 19:56 +0900 Martin Duerst
<duerst at it.aoyama.ac.jp> wrote:

> A specific comment on Paul's draft:
> 
> In section 3, it says:
> 
>    | 3) If a string contains any RandALCat character, a
> RandALCat    |   character MUST be the first character of the
> string, and    |   either a RandALCat character or NSM
> charcter MUST be the    |   last character of the string.
> 
> That should be fixed to read as follows:
> 
>    | 3) If a string contains any RandALCat character, a
> RandALCat    |   character MUST be the first character of the
> string, and    |   the string must end with RandALCat,
> possibly followed by    |   one or more NSM charcters.
> 
> or some such. We don't want strings that e.g. end with an NSM
> character that's preceeded by a digit or so.

Better be "some such", since "ending in X, [with X] possibly
followed by..." just doesn't make sense.

No criticism of your suggestion intended, since I think your
observation is correct.  But this illustrates why these things
involving relationships of characters within a string are hard
to get exactly right, whether we are trying to express them in
prose (as here) or in somewhat more formal contextual rules or
regular expressions.

    john



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