[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: [off-topic] xtext -- encoding declarations for text

• To: "John Cowan" <jcowan@r...>,"Rick Jelliffe" <ricko@a...>
• Subject: Re: [off-topic] xtext -- encoding declarations for text
• From: "Bob Foster" <bob@o...>
• Date: Fri, 23 May 2003 17:21:01 -0500
• Cc: <xml-dev@l...>
• References: <058301c31e13$b9200080$4bc8a8c0@A...> <20030523145432.GR1164@s...>

From: "John Cowan" <jcowan@r...>
> Rick Jelliffe scripsit:
>
> > Comments welcome.
>
> The following regex (to be interpreted as referring to bytes, not
characters)
> should reliably detect the presence of an xtext declaration.
>
> \A(\0*.){1,4}\0*(x\0*t\0*e\0*x\0*t\0* |\xA7\xA3\x85\xA7\xA3\x40)
>
> \A means the beginning of the string, \0* skips any number of null bytes
> introduced by UTF-16 or UTF-32 encodings, and the \xA7...\x40 is "xtext "
> in the common subset of EBCDIC.

No space at the end of ascii 'xtext'. It's not just that null bytes are
noise, but that the characters may be re-ordered along big/little-endian
lines. How is the requirement enforced that the 1-4 leading characters not
contain a-z etc.?

It would be interesting to see a regex that actually solved this problem,
including the optional bom, but I doubt I would want to use it. ;-}

Bob

• Follow-Ups:
  • Re: [off-topic] xtext -- encoding declarations for text
    • From: John Cowan <cowan@m...>

• References:
  • [off-topic] xtext -- encoding declarations for text
    • From: "Rick Jelliffe" <ricko@a...>
  • Re: [off-topic] xtext -- encoding declarations for text
    • From: John Cowan <jcowan@r...>

• Prev by Date: Re: Syntax + object model
• Next by Date: Re: [off-topic] xtext -- encoding declarations for text
• Previous by thread: Re: [off-topic] xtext -- encoding declarations for text
• Next by thread: Re: [off-topic] xtext -- encoding declarations for text
• Index(es):
  • Date
  • Thread