[xsl] XPath riddle

[Nicholas Giannadakis <ngiann@xxxxxxxxxx>]

 Dear All,

 Can you tell what the XPath expression that:
 "selects all C elements that come after A and have a D parent" is.

 That is, there might be a schema, which declares the unwanted instances of C
 as integers, while
 the other C declared has some anonymous complexType.

 <?xml version="1.0" encoding="UTF-8"?>
 <A>
         <B>
                 <C/>                                            <!-- DO NOT select this -->
                 <D>
                         <!-- recursion is introduced here -->
                         <C>                                     <!-- select this -->
                                 <B>
                                         <C/>                    <!-- DO NOT select this -->>
                                         <D>
                                                 <C/>            <!-- select this -->
                                         </D>
                                 </B>
                         </C>
                 </D>
         </B>
 </A>

 /A//D/C (/A/descendant::D/C) would suffice, or, better, /A//B/D/C
 (/A/descendant::B/D/C). But this would not rule out the possibility of the
 B/D/C pattern appearing somewhere after A in another context. I cannot find
 any XPath feature that would handle recursion.

 <?xml version="1.0" encoding="UTF-8"?>
 <A>
         <B>
                 <F>
                         <B>
                                 <D>
                                         <C/>                    <!-- this would be selected incorrectly -->
                                 </D>
                         </B>
                 </F>
                 <D>
                         <!-- recursion is introduced here -->
                         <C>                                     <!-- select this -->
                                 <B>
                                         <C/>                    <!-- DO NOT select this -->
                                         <D>
                                                 <C/>            <!-- select this -->
                                         </D>
                                 </B>
                         </C>
                 </D>
         </B>
 </A>

 Using /A/B/D/C | /A/B/D/C//B/D/C would overcome this, but you can see how I
 could create another problematic example...
 How does one find one's way around this, using a generic XPath approach?
 I am not saying this is good XML design. To the contrary! ... it is legal,
 nonetheless ...any ideas?

 regards,

 nikolas/



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