[relaxng-user] line terminator in compact syntax

[James Clark]

On Sat, 2003-12-06 at 21:36, David Tolpin wrote:

> [The specification] explicitly distinguishes between
> the newline marker and  \x{A},

Right.

>  and says that both newline markers and \x{A}
> can be present in the stream after newline normalization.

Right.

>  The grammar, further,
> mentions newline marker separate from \x{A}; and I understand it is that the newline
> marker is not any character but a special entry in the source stream.

Right. Newline markers get introduced by newline normalization.


> The grammar lists both &newline; and &#A; as line terminators. They are
> separate  in the grammar, and I understand that these are two different things.
> Am I wrong?

They are different things.

> I would understand, if neither \x{A} nor \x{D} were line terminators or spaces, but
> rather normal characters, disallowed everywhere  but in literals. I just don't understand
> the difference between xA and xD with regard to the language of the specification.

Let me try again. The fact that \x{A} is a line terminator means I can
write

## foo
## bar

equivalently as

## foo\x{A}##bar

Now consider

 x = """foo
bar"""

This is equivalent to

 x = """foo\x{A}bar"

regardless of whether the newline was represented as #xA, #xD or #xD #xA
in the input file.  It is never equivalent to

 x """foo\x{D}bar""" 

Thus if for some reason my input schema must be a single line, the fact
that \x{A} is treated is a line terminator is sufficient to allow this.
I can turn my multi-line schema into a single-line schema by replacing
each newline terminator by \x{A}.  Allowing \x{D} as a line-terminator
would not help, because transforming a schema by mapping a #xD into
\x{D} sometimes changes the meaning of the schema (i.e. when the #xD is
in a multiline string).

James