A most unique confection

by Simon St. Laurent

Related link: http://www.w3.org/TR/2004/WD-xmlschema-ref-20040309/



Although I have been a harsh critic of both the widely used W3C XML Schema and the far less common XPointer family of specifications, it was not until this week that I was granted the privilege of seeing the two of them united.



W3C XML Schema has for years been an unexpected guest at a ball, luring away partygoers with its many delightful promises, stealing their hearts and making it impossible for them to escape.



XPointer, though a distant relation in the W3C family, has spent years sulking in a corner, fending off suitors with threats of patents, with long, drawn-out engagements that come to naught, with unexpected complexities surfacing in what began as simple conversations.



But now! To see them dancing together, a sight hardly imaginable before. Such a strange pair, a couple united perhaps by chance and perhaps by destiny.



After all, who can resist the delicate rhythms to which they dance:



#xmlns(ipo=http://www.example.com/IPO) xscd(/complexType(ipo:Items)/sequence()/item/complexType()/@partNum)

#xmlns(ipo=http://www.example.com/IPO) xscd(/simpleType(ipo:SKU))
#xmlns(ipo=http://www.example.com/IPO) xscd(/simpleType(ipo:SKU)/pattern())

#xmlns(r=http://www.example.com/Report) xscd(/r:purchaseReport)
#xmlns(r=http://www.example.com/Report) xscd(/r:purchaseReport/complexType()/sequence()/r:regions)
#xmlns(r=http://www.example.com/Report) xscd(/r:purchaseReport/complexType()/sequence()/r:regions/identityConstraint(r:dummy2))


It must be true love. There's no other polite way to explain the dizziness this produces.



It's quite amazing to see these two come together. I feel it has borne out my most strongly-held convictions about them.



Ever have to say nice things about a partnership that brings out the worst of both sides?