Module structure 

Structural validation rules for XSD elements

This module provides validation functions for XSD structural constraints that cannot be expressed in the frame’s allows() method. These include:

• Mutually exclusive attributes: e.g., name XOR ref on elements
• Dependent attributes: e.g., keyref requires refer
• Prohibited combinations: e.g., top-level element cannot have minOccurs
• XSD version gates: e.g., xs:assert requires XSD 1.1

XSD Structural Constraints

Per W3C XSD 1.0 specification:

Element	Constraint
element (top)	Must have name, must not have ref/minOccurs/maxOccurs
element (local)	Must have exactly one of name or ref
attribute (top)	Must have name, must not have ref/use
attribute (local)	Must have exactly one of name or ref
simpleType	name required at top level, prohibited in local context
complexType	name required at top level, prohibited in local context
restriction	Must have base XOR inline type
extension	Must have base attribute
key/unique	Must have name attribute
keyref	Must have name and refer attributes
list	Must have itemType XOR inline simpleType
union	Must have memberTypes XOR inline simpleTypes

Structs

ValidationContext

Validation context for structural checks

Constants

XSD_1_1_ATTRIBUTES

XSD 1.1 attribute names that are not allowed in XSD 1.0 mode

XSD_1_1_ELEMENTS

XSD 1.1 element names that are not allowed in XSD 1.0 mode

Functions

validate_attribute_group_structure

Validate attribute group element structure

validate_attribute_structure

Validate attribute declaration structural constraints

validate_complex_type_structure

Validate complex type definition structure

validate_element_structure

Validate element declaration structural constraints

validate_extension_structure

Validate extension element structure

validate_group_structure

Validate model group (group) element structure

validate_import_structure

Validate import directive structure

validate_include_structure

Validate include directive structure

validate_key_unique_structure

Validate key/unique element structure

validate_keyref_structure

Validate keyref element structure

validate_list_structure

Validate list element structure

validate_notation_structure

Validate notation declaration structure

validate_redefine_structure

Validate redefine directive structure

validate_restriction_structure

Validate restriction element structure

validate_schema_structure

Validate xs:schema document structure

validate_simple_type_structure

Validate simple type definition structure

validate_union_structure

Validate union element structure

validate_xsd_version_attribute

Validate that an attribute is allowed in the current XSD version

validate_xsd_version_element

Validate that an element is allowed in the current XSD version