[DFDL-WG] Representing multiple spaces

[Mike Beckerle]

%WSP+; is one or more whitespaces. that might be what you want.

The only way to do one or more %SP; (I think you meant %SP*; not %ES*; - ES
is empty string) only is like this

dfdl:terminator="%SP; %SP;%SP; %SP;%SP;%SP; ..."
i.e, a whitepace separated list of one space, two spaces, three spaces,
etc. up to as high as you would like to go.

If that just won't cut it, then you have to go to something i call modeling
syntax as data:

You create a group

<group name="spaces">
   <sequence>
     <xs:element name="spaces" type="xs:string" dfdl:lengthKind="pattern"
dfdl:lengthPattern="\s*"/>
  </sequence>
</group>

This spaces group is a model for something that is just a syntactic feature
of your data.

Then you keep the group out of your logical infoset by using a hidden group
ref like so

<sequence>
  <element name="beforeSpaces" type="xs:string" dfdl:terminator="%SP;"/>
  <sequence dfdl:hiddenGroupRef="tns:spaces"/>
  <element name="afterSpaces" type="xs:string"dfdl:terminator="%SP;"/>
</sequence>

Here's what I'm not sure of....

In XSD, it would be ok to have multiple groups like this between elements,
because the elements aren't named "spaces", so the various instances of the
"spaces" element can't be confused. (There is no UPA problem.)

In DFDL, I'm not sure if we allow this:

<sequence dfdl:sequenceKind="ordered">
    <element name="foo" .../>
    <element name="spaces" .../>
    <element name="bar" .../>
    <element name="spaces".../>
     ....
</sequence>

I.e., more than one child element named "spaces" in the same sequence, but
it's not an array using minOccurs/maxOccurs and dfdl:occursCountKind, etc.

XML Schema would not have a problem with this, so long as those elements
are all required. (minOccurs >= 1).

I've sent a separate email to the dfdl-wg to see what others' opinions are
on this.



On Thu, Feb 28, 2013 at 3:03 PM, Garriss Jr., James P.
<jgarriss at mitre.org>wrote:

>  Suppose I have a terminator that can be multiple spaces, whether 0
> spaces, 1 space, 2 spaces, or more spaces.  No other types of whitespace
> allowed, just spaces.****
>
> ** **
>
> Because there’s this entity:  %WSP*;****
>
> ** **
>
> I assumed there would also be this entity:  %ES*;****
>
> ** **
>
> But there’s not.  Why not?  How would I represent this terminator?****
>
>
> TIA****
>
> --
>   dfdl-wg mailing list
>   dfdl-wg at ogf.org
>   https://www.ogf.org/mailman/listinfo/dfdl-wg
>



-- 
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology |
www.tresys.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.ogf.org/pipermail/dfdl-wg/attachments/20130228/a8b63b34/attachment.html>