Resolve a built-in datatype named by xsi:type (xsd:int, xsd:decimal,
xsd:string), which previously resolved only against schema-declared types and
so reported "unknown" and wrongly rejected the element. The built-in is now
resolved when it validly substitutes for the declared type per Schema-Validity
Assessment: the ur-type (anyType/anySimpleType) admits any type, and a bare
built-in declared type admits any built-in derived from it through the XSD
Part 2 datatype lattice (new BuiltinType.derives(from:)). An invalid built-in
substitution is a located error, not a silent acceptance.
Resolving the override correctly exposed two pre-existing gaps, both closed so
the change carries no invalid-instances-accepted regression:
- A simple-typed element rejects non-schema-instance attributes. A simple type
declares no attribute uses, so an element of simple type (including via an
xsi:type override, and including an xsi:nil element) may carry only xsi:* and
namespace attributes. Checked before the nil short-circuit.
- Identity-constraint fields compare in their value space when the selected
node carries an xsi:type. unique/key/keyref tuples compared lexically, so two
xsi:type="xsd:decimal" fields 3.0 and 3 were treated as distinct and a unique
violation was missed. Each field value now carries the type read from the
node's xsi:type and compares via SimpleType.valueMatches when both share a
built-in base, otherwise lexically.
XSTS: valid instances rejected 248 to 233; invalid instances accepted held at
165. Identity tests corrected to spec-valid schemas (an element carrying an
attribute must be a complex type, not type="xs:string").
Add the PureXML.Schema namespace validating XSD Part 2 built-in datatypes
and constraining facets. Built-ins span string/boolean/decimal, the bounded
integer family with intrinsic bounds, float/double, duration, the eight
date/time types, hexBinary, base64Binary, anyURI, QName, and the
Name/NCName/NMTOKEN/language family. Facets: length/minLength/maxLength,
pattern (via the regex engine), enumeration (value-space comparison),
whiteSpace, min/maxInclusive/Exclusive, totalDigits, fractionDigits.
Decimals compare exactly with no floating-point loss; date/time fields are
range-validated with leap years, 24:00:00, and timezone bounds.
Closes#8
