Re: More surprises (ID, ENTITY, NOTATION, ...)

> Section 4.3.4 of part 2 says: 
> 
>     [Definition:] pattern is a constraint on the value space of a
>     datatype which is achieved by constraining the lexical space to
>     literals which match a specific pattern. The value of pattern must
>     be a regular expression.

There is another problem in this paragraph. Namely, the pattern facet is
not a constraint on the value space.

One can apply a pattern facet [+-]\d+ to the integer type so that "+0"
is legal but "0" is legal. But how does this facet constrain zero in the
value space? It doesn't constitute any subset.

I don't think adding "... achieved by constraining the lexical space"
solves the problem.


regards,
----------------------
K.Kawaguchi
E-Mail: kohsukekawaguchi@yahoo.com

Received on Monday, 22 October 2001 13:27:46 UTC