- From: Michael Kay <mhk@mhk.me.uk>
- Date: Sun, 7 Mar 2004 00:27:51 -0000
- To: "'Lingzhi Zhang'" <lzhang@cse.ogi.edu>, "'dev xmlschema'" <xmlschema-dev@w3.org>
You are correct to say that both these instance documents are valid against this schema. The word "ambiguity" has a fairly technical meaning when discussing grammars, and it's not considered an "ambiguity" that more than one instance document should match the same schema. In fact, it's a rather essential feature. But it is sometimes a usability problem that you can't easily constrain what the document element should be (it can be any element that is globally declared). Michael Kay # -----Original Message----- # From: xmlschema-dev-request@w3.org [mailto:xmlschema-dev-request@w3.org] # On Behalf Of Lingzhi Zhang # Sent: 06 March 2004 23:41 # To: dev xmlschema # Subject: determine root element in the xml from schema # # # # Hi, # # I am confused of how to determine root element in the xml from a given # schema. It seems to me there is "ambiguity". # # Say if we have schema like: # <schema ...> # <element name="A"> # <complexType> # ... # <element ref="B"/> # ... # <complexType> # </element> # <element name="B"/> # <schema> # # Either xml: # <A><B></B></A> # # or xml: # <B></B> # # would be valid xml against the schema. So either A or B could be root # element in the xml. By just looking at the schema without looking at xml, # we can't tell which on would be root element in the xml. However, if a # user defines that schema, he/she usually means that A is the root. Isn't # it "ambiguous"? # # Stephen
Received on Saturday, 6 March 2004 19:27:57 UTC