[XSL-LIST Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] positional predicates in XPath vs XQL
I'm implementing an engine that evaluates XPath. I'm currently working on the part of the engine that implements positional predicates. I've previously worked this out for location paths in XQL, but I think the semantics are different in the two languages and want to make sure I understand the differences. In XQL if you say (pretending for the moment that positions start from 1 as they do in XPath, rather than 0): /section/para[ 1 ] and you have a tree that looks like this: 1 section 2 para 3 para 4 section 5 para 6 section 7 para 8 para 9 para you'll get back this nodeset: <2>, <5>, <7> You can paraphrase this XQL query as saying, "Give me back the 1st child node of each <section> element." Similarly, "/section/para[ 2 ]" returns <3>, <8>, and if you say "/section/para[ 3 ]", you get back the single node, <9>. To my understanding, the same location path in XPath only returns a single node, <2>. Is my understanding correct? Howard XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list
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