Re: issue #24 does an ixml processor have to match everything?

My apologies to the group; I have discovered that when trying to start a
discussion of issue #24, I failed to check what the spec currently says.
Had I done so, I hope that I would have written differently.

C. M. Sperberg-McQueen writes:

> At the end of the last call, we agreed that at our next call we would
> talk about issue #24, "Does ixml have to match the whole input?"
>
> In preparation for this topic, I would like to ...
> lay out a preliminary position in preparation for our discussion.


> ... my position on issue #24, going in to the discussion, is yes, a
> conforming ixml processor reports that the input, in its entirety, is a
> sentence in the language defined by the specified grammar, or that it is
> not. 

> That has several consequences:

> - A processor that wishes to support input streams of indeterminate
>   length will do so as a non-standard extension.

This is at best ill phrased.  The definition of processor conformance
makes clear that conforming processors may provide a user option for
this behavior.  Since the behavior is not described by the spec, it is
in some sense non-standard, but it is not non-conforming.  When I wrote
the paragraph above, I was thinking of 'non-standard' and
'non-conforming' as extensionally equivalent here; they are not.

> - A processor that wishes to offer a mode of operation in which
>   successively larger prefixes of the input are identified as sentences
>   in the language will do so as a non-standard extension.

The same applies:  the behavior is not standardized, but under the
current spec it's not non-conforming.

> - A processor that wishes to inform the user that while the input string
>   as a whole is not a sentence in the language, a particular substring
>   of the input *is* a sentence in the language can do so as part of its
>   error diagnostics.  If it falsely reports that the input as a whole is
>   a sentence, it is not conforming.

Finally a sentence that I still believe to be true.

> In all three cases, the rationale for the decision is the same: every
> attempt the CG has made to describe how conformance would work if the
> rule were changed has been unsatisfactory.

This now appears false, since I am not unhappy with the current wording
(now that I have bothered to look at it).

-- 
C. M. Sperberg-McQueen
Black Mesa Technologies LLC
http://blackmesatech.com

Received on Monday, 7 February 2022 16:47:09 UTC