xpath.h

libxml,在UNIX/LINUX下非常重要的一个库,为XML相关应用提供方便.目前上载的是最新版本,若要取得最新版本,请参考里面的readme.

 *    - a set of variable bindings 
 *    - a function library 
 *    - the set of namespace declarations in scope for the expression 
 * Following the switch to hash tables, this need to be trimmed up at
 * the next binary incompatible release.
 */

struct _xmlXPathContext {
    xmlDocPtr doc;			/* The current document */
    xmlNodePtr node;			/* The current node */

    int nb_variables_unused;		/* unused (hash table) */
    int max_variables_unused;		/* unused (hash table) */
    xmlHashTablePtr varHash;		/* Hash table of defined variables */

    int nb_types;			/* number of defined types */
    int max_types;			/* max number of types */
    xmlXPathTypePtr types;		/* Array of defined types */

    int nb_funcs_unused;		/* unused (hash table) */
    int max_funcs_unused;		/* unused (hash table) */
    xmlHashTablePtr funcHash;		/* Hash table of defined funcs */

    int nb_axis;			/* number of defined axis */
    int max_axis;			/* max number of axis */
    xmlXPathAxisPtr axis;		/* Array of defined axis */

    /* the namespace nodes of the context node */
    xmlNsPtr *namespaces;		/* Array of namespaces */
    int nsNr;				/* number of namespace in scope */
    void *user;				/* function to free */

    /* extra variables */
    int contextSize;			/* the context size */
    int proximityPosition;		/* the proximity position */

    /* extra stuff for XPointer */
    int xptr;				/* it this an XPointer context */
    xmlNodePtr here;			/* for here() */
    xmlNodePtr origin;			/* for origin() */

    /* the set of namespace declarations in scope for the expression */
    xmlHashTablePtr nsHash;		/* The namespaces hash table */
    xmlXPathVariableLookupFunc varLookupFunc;/* variable lookup func */
    void *varLookupData;		/* variable lookup data */

    /* Possibility to link in an extra item */
    void *extra;                        /* needed for XSLT */

    /* The function name and URI when calling a function */
    const xmlChar *function;
    const xmlChar *functionURI;

    /* function lookup function and data */
    xmlXPathFuncLookupFunc funcLookupFunc;/* function lookup func */
    void *funcLookupData;		/* function lookup data */

    /* temporary namespace lists kept for walking the namespace axis */
    xmlNsPtr *tmpNsList;		/* Array of namespaces */
    int tmpNsNr;			/* number of namespace in scope */

    /* error reporting mechanism */
    void *userData;                     /* user specific data block */
    xmlStructuredErrorFunc error;       /* the callback in case of errors */
    xmlError lastError;			/* the last error */
    xmlNodePtr debugNode;		/* the source node XSLT */

    /* dictionnary */
    xmlDictPtr dict;			/* dictionnary if any */
};

/*
 * The structure of a compiled expression form is not public.
 */

typedef struct _xmlXPathCompExpr xmlXPathCompExpr;
typedef xmlXPathCompExpr *xmlXPathCompExprPtr;

/**
 * xmlXPathParserContext:
 *
 * An XPath parser context. It contains pure parsing informations,
 * an xmlXPathContext, and the stack of objects.
 */
struct _xmlXPathParserContext {
    const xmlChar *cur;			/* the current char being parsed */
    const xmlChar *base;			/* the full expression */

    int error;				/* error code */

    xmlXPathContextPtr  context;	/* the evaluation context */
    xmlXPathObjectPtr     value;	/* the current value */
    int                 valueNr;	/* number of values stacked */
    int                valueMax;	/* max number of values stacked */
    xmlXPathObjectPtr *valueTab;	/* stack of values */

    xmlXPathCompExprPtr comp;		/* the precompiled expression */
    int xptr;				/* it this an XPointer expression */
    xmlNodePtr         ancestor;	/* used for walking preceding axis */
};

/************************************************************************
 *									*
 *			Public API					*
 *									*
 ************************************************************************/

/**
 * Objects and Nodesets handling
 */

XMLPUBVAR double xmlXPathNAN;
XMLPUBVAR double xmlXPathPINF;
XMLPUBVAR double xmlXPathNINF;

/* These macros may later turn into functions */
/**
 * xmlXPathNodeSetGetLength:
 * @ns:  a node-set
 *
 * Implement a functionality similar to the DOM NodeList.length.
 *
 * Returns the number of nodes in the node-set.
 */
#define xmlXPathNodeSetGetLength(ns) ((ns) ? (ns)->nodeNr : 0)
/**
 * xmlXPathNodeSetItem:
 * @ns:  a node-set
 * @index:  index of a node in the set
 *
 * Implements a functionality similar to the DOM NodeList.item().
 *
 * Returns the xmlNodePtr at the given @index in @ns or NULL if
 *         @index is out of range (0 to length-1)
 */
#define xmlXPathNodeSetItem(ns, index)				\
		((((ns) != NULL) && 				\
		  ((index) >= 0) && ((index) < (ns)->nodeNr)) ?	\
		 (ns)->nodeTab[(index)]				\
		 : NULL)
/**
 * xmlXPathNodeSetIsEmpty:
 * @ns: a node-set
 *
 * Checks whether @ns is empty or not.
 *
 * Returns %TRUE if @ns is an empty node-set.
 */
#define xmlXPathNodeSetIsEmpty(ns)                                      \
    (((ns) == NULL) || ((ns)->nodeNr == 0) || ((ns)->nodeTab == NULL))


XMLPUBFUN void XMLCALL		   
		    xmlXPathFreeObject		(xmlXPathObjectPtr obj);
XMLPUBFUN xmlNodeSetPtr XMLCALL	   
		    xmlXPathNodeSetCreate	(xmlNodePtr val);
XMLPUBFUN void XMLCALL		   
		    xmlXPathFreeNodeSetList	(xmlXPathObjectPtr obj);
XMLPUBFUN void XMLCALL		   
		    xmlXPathFreeNodeSet		(xmlNodeSetPtr obj);
XMLPUBFUN xmlXPathObjectPtr XMLCALL  
		    xmlXPathObjectCopy		(xmlXPathObjectPtr val);
XMLPUBFUN int XMLCALL		   
		    xmlXPathCmpNodes		(xmlNodePtr node1,
						 xmlNodePtr node2);
/**
 * Conversion functions to basic types.
 */
XMLPUBFUN int XMLCALL		   
		    xmlXPathCastNumberToBoolean	(double val);
XMLPUBFUN int XMLCALL		   
		    xmlXPathCastStringToBoolean	(const xmlChar * val);
XMLPUBFUN int XMLCALL		   
		    xmlXPathCastNodeSetToBoolean(xmlNodeSetPtr ns);
XMLPUBFUN int XMLCALL		   
		    xmlXPathCastToBoolean	(xmlXPathObjectPtr val);

XMLPUBFUN double XMLCALL		   
		    xmlXPathCastBooleanToNumber	(int val);
XMLPUBFUN double XMLCALL		   
		    xmlXPathCastStringToNumber	(const xmlChar * val);
XMLPUBFUN double XMLCALL		   
		    xmlXPathCastNodeToNumber	(xmlNodePtr node);
XMLPUBFUN double XMLCALL		   
		    xmlXPathCastNodeSetToNumber	(xmlNodeSetPtr ns);
XMLPUBFUN double XMLCALL		   
		    xmlXPathCastToNumber	(xmlXPathObjectPtr val);

XMLPUBFUN xmlChar * XMLCALL	   
		    xmlXPathCastBooleanToString	(int val);
XMLPUBFUN xmlChar * XMLCALL	   
		    xmlXPathCastNumberToString	(double val);
XMLPUBFUN xmlChar * XMLCALL	   
		    xmlXPathCastNodeToString	(xmlNodePtr node);
XMLPUBFUN xmlChar * XMLCALL	   
		    xmlXPathCastNodeSetToString	(xmlNodeSetPtr ns);
XMLPUBFUN xmlChar * XMLCALL	   
		    xmlXPathCastToString	(xmlXPathObjectPtr val);

XMLPUBFUN xmlXPathObjectPtr XMLCALL  
		    xmlXPathConvertBoolean	(xmlXPathObjectPtr val);
XMLPUBFUN xmlXPathObjectPtr XMLCALL  
		    xmlXPathConvertNumber	(xmlXPathObjectPtr val);
XMLPUBFUN xmlXPathObjectPtr XMLCALL  
		    xmlXPathConvertString	(xmlXPathObjectPtr val);

/**
 * Context handling.
 */
XMLPUBFUN xmlXPathContextPtr XMLCALL 
		    xmlXPathNewContext		(xmlDocPtr doc);
XMLPUBFUN void XMLCALL		   
		    xmlXPathFreeContext		(xmlXPathContextPtr ctxt);

/**
 * Evaluation functions.
 */
XMLPUBFUN long XMLCALL               
		    xmlXPathOrderDocElems	(xmlDocPtr doc);
XMLPUBFUN xmlXPathObjectPtr XMLCALL  
		    xmlXPathEval		(const xmlChar *str,
						 xmlXPathContextPtr ctx);
XMLPUBFUN xmlXPathObjectPtr XMLCALL  
		    xmlXPathEvalExpression	(const xmlChar *str,
						 xmlXPathContextPtr ctxt);
XMLPUBFUN int XMLCALL                
		    xmlXPathEvalPredicate	(xmlXPathContextPtr ctxt,
						 xmlXPathObjectPtr res);
/**
 * Separate compilation/evaluation entry points.
 */
XMLPUBFUN xmlXPathCompExprPtr XMLCALL 
		    xmlXPathCompile		(const xmlChar *str);
XMLPUBFUN xmlXPathCompExprPtr XMLCALL 
		    xmlXPathCtxtCompile		(xmlXPathContextPtr ctxt,
		    				 const xmlChar *str);
XMLPUBFUN xmlXPathObjectPtr XMLCALL   
		    xmlXPathCompiledEval	(xmlXPathCompExprPtr comp,
						 xmlXPathContextPtr ctx);
XMLPUBFUN void XMLCALL                
		    xmlXPathFreeCompExpr	(xmlXPathCompExprPtr comp);
#endif /* LIBXML_XPATH_ENABLED */
#if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED)
XMLPUBFUN void XMLCALL		   
		    xmlXPathInit		(void);
XMLPUBFUN int XMLCALL
		xmlXPathIsNaN	(double val);
XMLPUBFUN int XMLCALL
		xmlXPathIsInf	(double val);

#ifdef __cplusplus
}
#endif

#endif /* LIBXML_XPATH_ENABLED or LIBXML_SCHEMAS_ENABLED*/
#endif /* ! __XML_XPATH_H__ */