SaxonHE: How to use XSD types on XQuery execution-CodePudding

I have the following XML document:

<?xml version="1.0" encoding="UTF-8"?>
<root xsi:noNamespaceSchemaLocation="example.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <a>0.1</a>
    <b>0.2</b>
</root>

which is associated with the following XSD:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="root">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="a" type="xs:decimal"/>
                <xs:element name="b" type="xs:decimal"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

Using this code snippet I execute an XQuery expression let $a := /root/a, $b := /root/b, $res := $a $b return $res:

var proc = new Processor(false);

var builder = proc.newDocumentBuilder();
builder.setBaseURI(URI.create("http://test.ru"));

var file = new File(filePath);
var doc = builder.build(file);

var expression = "let $a := /root/a, $b := /root/b, $res := $a   $b return $res";

var compiler = proc.newXQueryCompiler();
var executable = compiler.compile(expression);
var selector = executable.load();
selector.setContextItem(doc);

return selector.evaluate();

The result is 0.30000000000000004. According this question (SaxonHE XQuery sum operation precision) it is because of the default number/xs:double type.

However, I have an XSD in which elements a and b have xs:decimal type. It there are any way to tell Saxon use types from XSD on XQuery expression executions?

CodePudding user response：

If you are able to switch to Saxon EE then you can of course use schema-aware XQuery with e.g. https://www.w3.org/TR/xquery-31/#id-schema-import and the schema will be used and your values will be xs:decimals. Or with the right settings the document might be parsed and validated based on the schemaLocation attribute (https://www.saxonica.com/html/documentation10/schema-processing/saqueryapi.html).

Even in HE, however, nothing prevents you from doing let $a := xs:decimal(/root/a), $b := xs:decimal(/root/b), you might need to declare the namespace in the query prolog.