/*

 * Summary: XML Path Language implementation

 * Description: API for the XML Path Language implementation

 *

 * XML Path Language implementation

 * XPath is a language for addressing parts of an XML document,

 * designed to be used by both XSLT and XPointer

 *     http://www.w3.org/TR/xpath

 *

 * Implements

 * W3C Recommendation 16 November 1999

 *     http://www.w3.org/TR/1999/REC-xpath-19991116

 *

 * Copy: See Copyright for the status of this software.

 *

 * Author: Daniel Veillard

 */

#ifndef __XML_XPATH_H__

#define __XML_XPATH_H__

#include <libxml/xmlversion.h>

#ifdef LIBXML_XPATH_ENABLED

#include <libxml/xmlerror.h>

#include <libxml/tree.h>

#include <libxml/hash.h>

#endif /* LIBXML_XPATH_ENABLED */

#if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED)

#ifdef __cplusplus

extern "C" {

#endif

#endif /* LIBXML_XPATH_ENABLED or LIBXML_SCHEMAS_ENABLED */

#ifdef LIBXML_XPATH_ENABLED

typedef struct _xmlXPathContext xmlXPathContext;

typedef xmlXPathContext *xmlXPathContextPtr;

typedef struct _xmlXPathParserContext xmlXPathParserContext;

typedef xmlXPathParserContext *xmlXPathParserContextPtr;

/**

 * The set of XPath error codes.

 */

typedef enum {

    XPATH_EXPRESSION_OK = 0,

    XPATH_NUMBER_ERROR,

    XPATH_UNFINISHED_LITERAL_ERROR,

    XPATH_START_LITERAL_ERROR,

    XPATH_VARIABLE_REF_ERROR,

    XPATH_UNDEF_VARIABLE_ERROR,

    XPATH_INVALID_PREDICATE_ERROR,

    XPATH_EXPR_ERROR,

    XPATH_UNCLOSED_ERROR,

    XPATH_UNKNOWN_FUNC_ERROR,

    XPATH_INVALID_OPERAND,

    XPATH_INVALID_TYPE,

    XPATH_INVALID_ARITY,

    XPATH_INVALID_CTXT_SIZE,

    XPATH_INVALID_CTXT_POSITION,

    XPATH_MEMORY_ERROR,

    XPTR_SYNTAX_ERROR,

    XPTR_RESOURCE_ERROR,

    XPTR_SUB_RESOURCE_ERROR,

    XPATH_UNDEF_PREFIX_ERROR,

    XPATH_ENCODING_ERROR,

    XPATH_INVALID_CHAR_ERROR,

    XPATH_INVALID_CTXT

} xmlXPathError;

/*

 * A node-set (an unordered collection of nodes without duplicates).

 */

typedef struct _xmlNodeSet xmlNodeSet;

typedef xmlNodeSet *xmlNodeSetPtr;

struct _xmlNodeSet {

    int nodeNr;			/* number of nodes in the set */

    int nodeMax;		/* size of the array as allocated */

    xmlNodePtr *nodeTab;	/* array of nodes in no particular order */

    /* @@ with_ns to check wether namespace nodes should be looked at @@ */

};

/*

 * An expression is evaluated to yield an object, which

 * has one of the following four basic types:

 *   - node-set

 *   - boolean

 *   - number

 *   - string

 *

 * @@ XPointer will add more types !

 */

typedef enum {

    XPATH_UNDEFINED = 0,

    XPATH_NODESET = 1,

    XPATH_BOOLEAN = 2,

    XPATH_NUMBER = 3,

    XPATH_STRING = 4,

    XPATH_POINT = 5,

    XPATH_RANGE = 6,

    XPATH_LOCATIONSET = 7,

    XPATH_USERS = 8,

    XPATH_XSLT_TREE = 9  /* An XSLT value tree, non modifiable */

} xmlXPathObjectType;

typedef struct _xmlXPathObject xmlXPathObject;

typedef xmlXPathObject *xmlXPathObjectPtr;

struct _xmlXPathObject {

    xmlXPathObjectType type;

    xmlNodeSetPtr nodesetval;

    int boolval;

    double floatval;

    xmlChar *stringval;

    void *user;

    int index;

    void *user2;

    int index2;

};

/**

 * xmlXPathConvertFunc:

 * @obj:  an XPath object

 * @type:  the number of the target type

 *

 * A conversion function is associated to a type and used to cast

 * the new type to primitive values.

 *

 * Returns -1 in case of error, 0 otherwise

 */

typedef int (*xmlXPathConvertFunc) (xmlXPathObjectPtr obj, int type);

/*

 * Extra type: a name and a conversion function.

 */

typedef struct _xmlXPathType xmlXPathType;

typedef xmlXPathType *xmlXPathTypePtr;

struct _xmlXPathType {

    const xmlChar         *name;		/* the type name */

    xmlXPathConvertFunc func;		/* the conversion function */

};

/*

 * Extra variable: a name and a value.

 */

typedef struct _xmlXPathVariable xmlXPathVariable;

typedef xmlXPathVariable *xmlXPathVariablePtr;

struct _xmlXPathVariable {

    const xmlChar       *name;		/* the variable name */

    xmlXPathObjectPtr value;		/* the value */

};

/**

 * xmlXPathEvalFunc:

 * @ctxt: an XPath parser context

 * @nargs: the number of arguments passed to the function

 *

 * An XPath evaluation function, the parameters are on the XPath context stack.

 */

typedef void (*xmlXPathEvalFunc)(xmlXPathParserContextPtr ctxt,

	                         int nargs);

/*

 * Extra function: a name and a evaluation function.

 */

typedef struct _xmlXPathFunct xmlXPathFunct;

typedef xmlXPathFunct *xmlXPathFuncPtr;

struct _xmlXPathFunct {

    const xmlChar      *name;		/* the function name */

    xmlXPathEvalFunc func;		/* the evaluation function */

};

/**

 * xmlXPathAxisFunc:

 * @ctxt:  the XPath interpreter context

 * @cur:  the previous node being explored on that axis

 *

 * An axis traversal function. To traverse an axis, the engine calls

 * the first time with cur == NULL and repeat until the function returns

 * NULL indicating the end of the axis traversal.

 *

 * Returns the next node in that axis or NULL if at the end of the axis.

 */

typedef xmlXPathObjectPtr (*xmlXPathAxisFunc) (xmlXPathParserContextPtr ctxt,

				 xmlXPathObjectPtr cur);

/*

 * Extra axis: a name and an axis function.

 */

typedef struct _xmlXPathAxis xmlXPathAxis;

typedef xmlXPathAxis *xmlXPathAxisPtr;

struct _xmlXPathAxis {

    const xmlChar      *name;		/* the axis name */

    xmlXPathAxisFunc func;		/* the search function */

};

/**

 * xmlXPathFunction:

 * @ctxt:  the XPath interprestation context

 * @nargs:  the number of arguments

 *

 * An XPath function.

 * The arguments (if any) are popped out from the context stack

 * and the result is pushed on the stack.

 */

typedef void (*xmlXPathFunction) (xmlXPathParserContextPtr ctxt, int nargs);

/*

 * Function and Variable Lookup.

 */

/**

 * xmlXPathVariableLookupFunc:

 * @ctxt:  an XPath context

 * @name:  name of the variable

 * @ns_uri:  the namespace name hosting this variable

 *

 * Prototype for callbacks used to plug variable lookup in the XPath

 * engine.

 *

 * Returns the XPath object value or NULL if not found.

 */

typedef xmlXPathObjectPtr (*xmlXPathVariableLookupFunc) (void *ctxt,

                                         const xmlChar *name,

                                         const xmlChar *ns_uri);

/**

 * xmlXPathFuncLookupFunc:

 * @ctxt:  an XPath context

 * @name:  name of the function

 * @ns_uri:  the namespace name hosting this function

 *

 * Prototype for callbacks used to plug function lookup in the XPath

 * engine.

 *

 * Returns the XPath function or NULL if not found.

 */

typedef xmlXPathFunction (*xmlXPathFuncLookupFunc) (void *ctxt,

					 const xmlChar *name,

					 const xmlChar *ns_uri);

/**

 * xmlXPathFlags:

 * Flags for XPath engine compilation and runtime

 */

/**

 * XML_XPATH_CHECKNS:

 *

 * check namespaces at compilation

 */

#define XML_XPATH_CHECKNS (1<<0)

/**

 * XML_XPATH_NOVAR:

 *

 * forbid variables in expression

 */

#define XML_XPATH_NOVAR	  (1<<1)

/**

 * xmlXPathContext:

 *

 * Expression evaluation occurs with respect to a context.

 * he context consists of:

 *    - a node (the context node) 

 *    - a node list (the context node list) 

 *    - 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 */

    int flags;				/* flags to control compilation */

};

/*

 * 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