- From: Jeni Tennison <jeni@jenitennison.com>
- Date: Tue, 8 Jan 2002 08:23:57 +0000
- To: www-xpath-comments@w3.org
- CC: xsl-list@lists.mulberrytech.com
Mike wrote: >> For all that there are lots of ways of comparing values in XPath 2.0, >> there doesn't seem to be one that compares sequences. >> >> If you have something like: >> >> <line start="0 300" end="300 0" /> >> >> where start and end both have typed values - @start is the sequence >> of two integers (0, 300) and @end is the sequence of two integers >> (300, 0). In this particular language, @start and @end are x,y >> coordinates. How can you work out whether start and end have the >> same value? > > I think you're right, this is an omission that we need to remedy. > I'd suggest a function compare-sequences(sequence, sequence), > perhaps with an optional collation argument, that returns -1, 0, or > +1, in the same way as compare(). It should be based on pairwise > comparison of items in the two sequences, each pair being compared > using the eq and lt operators. Phil Wadler has referred to this as > "lexicographic comparison", but I'm not sure most people would > understand that term correctly. There are two functions that do compare sequences: xf:sequence-deep-equal() xf:sequence-node-equal() Following the same scheme, the one I'm after here would have the signature: xf:sequence-value-equal(item* $parameter1, item* $parameter2) => boolean? xf:sequence-value-equal(item* $parameter1, item* $parameter2, anyURI $collationLiteral) => boolean? Cheers, Jeni --- Jeni Tennison http://www.jenitennison.com/
Received on Tuesday, 8 January 2002 03:23:59 UTC