- From: Biron,Paul V <Paul.V.Biron@kp.org>
- Date: Wed, 12 Dec 2001 09:21:56 -0800
- To: "'Sverre Hvammen Johansen'" <sj@birdstep.com>, "'www-xml-schema-comments@w3.org'" <www-xml-schema-comments@w3.org>
> -----Original Message----- > From: Sverre Hvammen Johansen [SMTP:sj@birdstep.com] > Sent: Tuesday, December 11, 2001 7:39 AM > To: www-xml-schema-comments@w3.org > Subject: Bug: XML Schema Part 2: Datatypes Appendix E Regular > Expression > > I am working on an implementation of regular expression based on the > specification found in XML Schema Part 2, appendix E. > > I have found one construct which is ambiguous: > > [.] > > There are two possible leftmost derivations for this construct: > > regExp => branch => piece => atom => charClass => charClassExpr => > '[' charGroup ']' => '[' posCharGroup ']' => '[' charRange ']' => > '[' XmlCharInDash ']' => '[.]' > > and: > > regExp => branch => piece => atom => charClass => charClassExpr => > '[' charGroup ']' => '[' posCharGroup ']' => '[' charClassEsc ']' => > '[' MultiCharEsc ']' => '[.]' > > The first alternative gives the single character '.' while the second > gives the multi character escape 'any character'. I expect that the > first alternative is the intended solution for the specification. > > I suggest to change the specification to the following: > > [11] charClass ::= charClassEsc | charClassExpr | '.' > [37] MultiCharEsc::= '\' [sSiIcCdDwW] > Thanx for your comment. This ambiguity has already been identified and is noted in the Schema Errata [1] as E2-10. pvb References [1] http://www.w3.org/2001/05/xmlschema-errata#Errata2
Received on Wednesday, 12 December 2001 12:36:55 UTC