Re: PI, XMLDecl, and EncodingPI

Tim Bray (tbray@textuality.com)
Wed, 03 Dec 1997 17:45:40 -0800


At 06:11 PM 03/12/97 -0700, Chris Hubick wrote:
> Within a PI is the Name "xml" reserved? If it is, should
>there not be a [wfc] on PI stating so?

In fact, in the latest rev, we wired it right into the grammar.

> By the current definition any XMLDecl and EncodingPI is also
>a valid PI. In a prolog an XMLDecl is optional, and is followed
>by Misc, which includes PI.
> Ok, so I have can have an XML file with no XMLDecl
>(it's optional) followed by "<?xml version="blah" encoding=5?>" which
>matches PI, in my Misc*. And this is legal?

Nope. And the grammar will getcha, because this no longer matches PI.

>Shouldn't [19] PI have an S? at the end before '?>' ?

No, because Char includes S

>[17] PCData ::= [^<&]+
>rather than the current:
>[17] PCData ::= [^<&]*
>In my recursive descent parses to:

It can't be +, because the empty string must match PCData. You'll just
have to figure out how to stop descending.

-Tim