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/*
* xpath.c: interface for XML Path Language implementation
*
* Reference: W3C Working Draft 5 July 1999
* http://www.w3.org/Style/XSL/Group/1999/07/xpath-19990705.html
*
* See COPYRIGHT for the status of this software
*
* Author: daniel@veillard.com
*/
#ifndef __XML_XPATH_H__
#define __XML_XPATH_H__
#include <libxml/tree.h>
#include <libxml/hash.h>
#ifdef __cplusplus
extern "C" {
#endif
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
} 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 */
};
/**
* 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 */
void *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 */
void *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 */
};
/*
* 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 */
};
/**
* 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);
/************************************************************************
* *
* Public API *
* *
************************************************************************/
/**
* Objects and Nodesets handling
*/
LIBXML_DLL_IMPORT extern double xmlXPathNAN;
LIBXML_DLL_IMPORT extern double xmlXPathPINF;
LIBXML_DLL_IMPORT extern double xmlXPathNINF;
int xmlXPathIsNaN (double val);
int xmlXPathIsInf (double val);
/* 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))
void xmlXPathFreeObject (xmlXPathObjectPtr obj);
xmlNodeSetPtr xmlXPathNodeSetCreate (xmlNodePtr val);
void xmlXPathFreeNodeSetList (xmlXPathObjectPtr obj);
void xmlXPathFreeNodeSet (xmlNodeSetPtr obj);
xmlXPathObjectPtr xmlXPathObjectCopy (xmlXPathObjectPtr val);
int xmlXPathCmpNodes (xmlNodePtr node1,
xmlNodePtr node2);
/**
* Conversion functions to basic types.
*/
int xmlXPathCastNumberToBoolean (double val);
int xmlXPathCastStringToBoolean (const xmlChar * val);
int xmlXPathCastNodeSetToBoolean (xmlNodeSetPtr ns);
int xmlXPathCastToBoolean (xmlXPathObjectPtr val);
double xmlXPathCastBooleanToNumber (int val);
double xmlXPathCastStringToNumber (const xmlChar * val);
double xmlXPathCastNodeToNumber (xmlNodePtr node);
double xmlXPathCastNodeSetToNumber (xmlNodeSetPtr ns);
double xmlXPathCastToNumber (xmlXPathObjectPtr val);
xmlChar * xmlXPathCastBooleanToString (int val);
xmlChar * xmlXPathCastNumberToString (double val);
xmlChar * xmlXPathCastNodeToString (xmlNodePtr node);
xmlChar * xmlXPathCastNodeSetToString (xmlNodeSetPtr ns);
xmlChar * xmlXPathCastToString (xmlXPathObjectPtr val);
xmlXPathObjectPtr xmlXPathConvertBoolean (xmlXPathObjectPtr val);
xmlXPathObjectPtr xmlXPathConvertNumber (xmlXPathObjectPtr val);
xmlXPathObjectPtr xmlXPathConvertString (xmlXPathObjectPtr val);
/**
* Context handling.
*/
void xmlXPathInit (void);
xmlXPathContextPtr xmlXPathNewContext (xmlDocPtr doc);
void xmlXPathFreeContext (xmlXPathContextPtr ctxt);
/**
* Evaluation functions.
*/
xmlXPathObjectPtr xmlXPathEval (const xmlChar *str,
xmlXPathContextPtr ctx);
xmlXPathObjectPtr xmlXPathEvalExpression (const xmlChar *str,
xmlXPathContextPtr ctxt);
int xmlXPathEvalPredicate (xmlXPathContextPtr ctxt,
xmlXPathObjectPtr res);
/**
* Separate compilation/evaluation entry points.
*/
xmlXPathCompExprPtr xmlXPathCompile (const xmlChar *str);
xmlXPathObjectPtr xmlXPathCompiledEval (xmlXPathCompExprPtr comp,
xmlXPathContextPtr ctx);
void xmlXPathFreeCompExpr (xmlXPathCompExprPtr comp);
#ifdef __cplusplus
}
#endif
#endif /* ! __XML_XPATH_H__ */
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