Module callbacks 

C ABI callback function type definitions — matching upstream callback signatures (§14, §20).

This module defines all function pointer types used in public upstream structures: SAX1 callbacks, SAX2 callbacks, error callbacks, validity callbacks, XPath callbacks, I/O callbacks, resource loader callbacks, encoding callbacks, and the SAX locator.

Phase 1 status

Complete — all callback types from upstream headers are defined.

Safety

All callback types are unsafe extern "C" because they are called across the FFI boundary with C calling conventions. The caller must ensure:

• Function pointers are non-null before invocation (unless nullable per upstream contract)
• Pointers passed to callbacks remain valid for the callback’s duration
• Callbacks observe the upstream ownership/lifetime contract
• Thread safety matches upstream expectations

Structs

_xmlSAXLocator

The SAX locator structure providing line/column information.

Type Aliases

attributeDeclSAXFunc

Callback for attribute declaration.

cdataBlockSAXFunc

Callback for CDATA block.

charactersSAXFunc

Callback for character data.

commentSAXFunc

Callback for comments.

elementDeclSAXFunc

Callback for element declaration.

endDocumentSAXFunc

Callback for document end.

endElementNsSAX2Func

Callback for element end (SAX2/namespaced).

endElementSAXFunc

Callback for element end (SAX1).

entityDeclSAXFunc

Callback for entity declaration.

errorSAXFunc

Callback for errors (printf-style, variadic at C call site).

externalSubsetSAXFunc

Callback for external subset notification.

fatalErrorSAXFunc

Callback for fatal errors (printf-style, variadic at C call site).

getEntitySAXFunc

Callback to get an entity.

getParameterEntitySAXFunc

Callback to get a parameter entity.

hasExternalSubsetSAXFunc

Callback: does the document have an external subset?

hasInternalSubsetSAXFunc

Callback: does the document have an internal subset?

ignorableWhitespaceSAXFunc

Callback for ignorable whitespace.

initSAXFunc

Callback for initializing the SAX handler.

internalSubsetSAXFunc

Callback for internal DTD subset notification.

isStandaloneSAXFunc

Callback for standalone document declaration.

notationDeclSAXFunc

Callback for notation declaration.

processingInstructionSAXFunc

Callback for processing instructions.

referenceSAXFunc

Callback for entity reference.

resolveEntitySAXFunc

Callback to resolve an external entity.

setDocumentLocatorSAXFunc

Callback to set the document locator.

startDocumentSAXFunc

Callback for document start.

startElementNsSAX2Func

Callback for element start (SAX2/namespaced).

startElementSAXFunc

Callback for element start (SAX1).

unparsedEntityDeclSAXFunc

Callback for unparsed entity declaration.

warningSAXFunc

Callback for warnings (printf-style, variadic at C call site).

xmlCatalogPreferFunc

Catalog preference callback.

xmlCharEncConvImpl

Character encoding conversion implementation.

xmlCharEncodingInputFunc

Character encoding input conversion function.

xmlCharEncodingOutputFunc

Character encoding output conversion function.

xmlFreeFunc

Free function type for allocator hooks.

xmlGenericErrorFunc

Generic error handler callback (printf-style, variadic at C call site).

xmlHashCopier

Copier function for hash table entries.

xmlHashDeallocator

Deallocator function for hash table entries.

xmlHashScanner

Scanner function for hash table entries.

xmlHashScannerFull

Full scanner function for hash table entries.

xmlInputCloseCallback

Close callback for custom input.

xmlInputReadCallback

Read callback for custom input.

xmlMallocFunc

Malloc function type for allocator hooks.

xmlModuleRegisterFunc

Module register/unregister callback.

xmlOutputCloseCallback

Close callback for custom output.

xmlOutputWriteCallback

Write callback for custom output.

xmlReallocFunc

Realloc function type for allocator hooks.

xmlResourceLoader

Resource loader callback.

xmlSAXLocatorPtr

Pointer to a SAX locator.

xmlStrdupFunc

Strdup function type for allocator hooks.

xmlStreamCtxtPtr

Stream callback for pattern matching.

xmlStructuredErrorFunc

Structured error handler callback.

xmlValidityErrorFunc

Validity error handler callback (printf-style, variadic at C call site).

xmlValidityWarningFunc

Validity warning handler callback (printf-style, variadic at C call site).

xmlXPathFuncLookupFunc

Function lookup function for XPath extensions.

xmlXPathVariableLookupFunc

Variable lookup function for XPath.