The type called DFDLExpressionOrPatternOrNothing only makes sense for use in one place - the element value of an assert or discriminator.

Regards

Steve Hanson
Architect, IBM Data Format Description Language (DFDL)
Co-Chair, OGF DFDL Working Group
IBM SWG, Hursley, UK
smh@uk.ibm.com
tel:+44-1962-815848

From: Suman Kalia <kalia@ca.ibm.com>
To: Mike Beckerle <mbeckerle.dfdl@gmail.com>,
Cc: dfdl-wg@ogf.org, dfdl-wg-bounces@ogf.org
Date: 19/03/2013 17:29
Subject: Re: [DFDL-WG] whitespace in DFDL annotations: right now regex is xs:string, expression is xs:token
Sent by: dfdl-wg-bounces@ogf.org

Mike - I am not sure but my gut feeling is that it would start with the most restrictive one first. i.e If empty string ( assuming it has length facet 1) - would match Nothing , then xsd:token which is restricted form of xs:string. I think you are going to get string with white spaces collpsed ( xsd:token) if it not empty string. You can run few tests to see the behavior..

Suman Kalia
IBM Canada Lab
WMB Toolkit Architect and Development Lead
Tel: 905-413-3923 T/L 313-3923
Email: kalia@ca.ibm.com

For info on Message broker
http://www.ibm.com/developerworks/websphere/zones/businessintegration/wmb.html

From: Mike Beckerle <mbeckerle.dfdl@gmail.com>
To: dfdl-wg@ogf.org,
Date: 03/19/2013 12:43 PM
Subject: [DFDL-WG] whitespace in DFDL annotations: right now regex is xs:string, expression is xs:token
Sent by: dfdl-wg-bounces@ogf.org

This came up on the call. The schemas I have for DFDL annotations have DFDLRegularExpression as an xs:string, and DFDLExpression as an xs:token. I have no clue what a union of these types behaves like. But we have a union called DFDLExpressionOrPatternOrNothing which is a 3-way union of DFDLExpression, DFDLRegularExpression, and EmptyString (which is also derived from xs:string but has length facet of 0 as well.

--
Mike Beckerle | OGF DFDL Workgroup Co-Chair | Tresys Technology | www.tresys.com-- dfdl-wg mailing list dfdl-wg@ogf.orghttps://www.ogf.org/mailman/listinfo/dfdl-wg -- dfdl-wg mailing list dfdl-wg@ogf.org https://www.ogf.org/mailman/listinfo/dfdl-wg

Unless stated otherwise above:
IBM United Kingdom Limited - Registered in England and Wales with number 741598.
Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU