OK, I tried this:
<xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
xmlns:xs="http://www.w3.org/2001/XMLSchema"; xmlns:my="my:my"
exclude-result-prefixes="xs my">
<xsl:output method="text"/>
<xsl:import-schema>
<xs:schema xsl:validation="strict">
<xs:simpleType name="numeric">
<xs:union>
<xs:simpleType>
<xs:restriction base="xs:decimal"/>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:integer"/>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:float"/>
</xs:simpleType>
<xs:simpleType>
<xs:restriction base="xs:double"/>
</xs:simpleType>
</xs:union>
</xs:simpleType>
</xs:schema>
</xsl:import-schema>
<xsl:template match="/">
<xsl:sequence select="3 castable as numeric"/>
=============================================
<xsl:sequence select="my:add(3.3 cast as numeric, 5.787 cast as numeric)"/>
</xsl:template>
<xsl:function name="my:add" as="numeric">
<xsl:param name="pLeft" as="numeric"/>
<xsl:param name="pRight" as="numeric"/>
<xsl:sequence select="($pLeft + $pRight) cast as numeric"/>
</xsl:function>
</xsl:stylesheet>
And it works as expecting, producing:
true
=============================================
9.087
However, if I omit any of the "cast as" constructors I get error from
SaxonEE 9.5.1.3 (invoked from Oxygen):
"XTTE0790: Required item type of second argument of my:add() is
numeric; supplied value has item type xs:decimal"
Or, if I evaluate: "3 instance of numeric", the result is false().
Is my understanding wrong that I can provide an instance of xs:decimal
anywhere where "numeric" is expected, or is this a bug in the XSLT
processor?
To remind, here is the relevant quote from the XPath 3.0 Recommendation:
"Pure union types have the property that every instance of an atomic type
defined as one of the member types of the union is also a valid instance
of the union type."
Cheers,
Dimitre
On Sat, May 3, 2014 at 7:29 PM, Dimitre Novatchev
dnovatchev(_at_)gmail(_dot_)com
<xsl-list-service(_at_)lists(_dot_)mulberrytech(_dot_)com> wrote:
I am reading the XPath 3.0 Recommendation.
The definition of "pure union type" is:
"[Definition: A pure union type is an XML Schema union type that
satisfies the following constraints: (1) {variety} is union, (2) the
{facets} property is empty, (3) no type in the transitive membership
of the union type has {variety} list, and (4) no type in the
transitive membership of the union type is a type with {variety} union
having a non-empty {facets} property].
Note:
The definition of pure union type excludes union types derived by
non-trivial restriction from other union types, as well as union types
that include list types in their membership. Pure union types have the
property that every instance of an atomic type defined as one of the
member types of the union is also a valid instance of the union type."
My Questions:
1. In the phrase: "The definition of pure union type excludes union
types derived by non-trivial restriction from other union types", what
is meant to be a "non-trivial restriction"?
2. Can somebody provide a meaningful example? For example, can we
define a "my:numeric" pure union type as the union of xs:decimal,
xs:integer, xs:float, xs:double, ..., etc ? If yes, could somebody
provide the XML Schema type definition of this pure union type? I
believe that this type is absolutely necessary to use for the
arguments and results of functions (and operators) defined on numbers.
--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
To achieve the impossible dream, try going to sleep.
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.
--
Cheers,
Dimitre Novatchev
---------------------------------------
Truly great madness cannot be achieved without significant intelligence.
---------------------------------------
To invent, you need a good imagination and a pile of junk
-------------------------------------
Never fight an inanimate object
-------------------------------------
To avoid situations in which you might make mistakes may be the
biggest mistake of all
------------------------------------
Quality means doing it right when no one is looking.
-------------------------------------
You've achieved success in your field when you don't know whether what
you're doing is work or play
-------------------------------------
To achieve the impossible dream, try going to sleep.
-------------------------------------
Facts do not cease to exist because they are ignored.
-------------------------------------
Typing monkeys will write all Shakespeare's works in 200yrs.Will they
write all patents, too? :)
-------------------------------------
I finally figured out the only reason to be alive is to enjoy it.
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