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/*
* Copyright (c) 2010-2011 Florian Forster <ff at octo.it>
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/**
* \file yajl_tree.h
*
* Parses JSON data and returns the data in tree form.
*
* \author Florian Forster
* \date August 2010
*/
#ifndef YAJL_TREE_H
#define YAJL_TREE_H 1
#include <stdint.h>
#include <inttypes.h>
#include <yajl/yajl_common.h>
/* Forward declaration, because "yajl_val_object_t" and "yajl_val_array"
* contain "yajl_val" and "yajl_val" can be an object or an array. */
typedef struct yajl_val_s * yajl_val;
#define YAJL_NUMBER_INT_VALID 0x01
#define YAJL_NUMBER_DOUBLE_VALID 0x02
/** Structure describing a JSON number. */
typedef struct yajl_val_number_s
{
/** Holds the raw value of the number, in string form. */
char *r;
/** Holds the integer value of the number, if possible. */
long long i;
/** Holds the double value of the number, if possible. */
double d;
/** Signals whether the \em value_int and \em value_double members are
* valid. See \c YAJL_NUMBER_INT_VALID and \c YAJL_NUMBER_DOUBLE_VALID. */
unsigned int flags;
} yajl_val_number;
/**
* Structure describing a JSON object.
*
* \sa yajl_val_array_s
*/
typedef struct yajl_val_object_s
{
/** Array of keys in the JSON object. */
const char **keys;
/** Array of values in the JSON object. */
yajl_val *values;
/** Number of key-value-pairs in the JSON object. */
size_t len;
} yajl_val_object;
/**
* Structure describing a JSON array.
*
* \sa yajl_val_object_s
*/
typedef struct yajl_val_array_s
{
/** Array of elements in the JSON array. */
yajl_val *values;
/** Number of elements in the JSON array. */
size_t len;
} yajl_val_array;
#define YAJL_TYPE_STRING 1
#define YAJL_TYPE_NUMBER 2
#define YAJL_TYPE_OBJECT 3
#define YAJL_TYPE_ARRAY 4
#define YAJL_TYPE_TRUE 5
#define YAJL_TYPE_FALSE 6
#define YAJL_TYPE_NULL 7
/**
* Struct describing a general JSON value.
*
* Each value is one of the seven types above. For "string", "number",
* "object", and "array" additional data is available in the "data" union. Use
* the "YAJL_IS_*" and "YAJL_TO_*" macros below to check for the correct type
* and cast the struct.
*
* \sa yajl_val_string, yajl_val_number, yajl_val_object,
* yajl_val_array
*/
struct yajl_val_s
{
/** Type of the value contained. Use the "YAJL_IS_*" macors to check for a
* specific type. */
uint8_t type;
/** Type-specific data. Use the "YAJL_TO_*" macros to access these
* members. */
union
{
char * string;
yajl_val_number number;
yajl_val_object object;
yajl_val_array array;
} data;
};
/**
* Parse a string.
*
* Parses an null-terminated string containing JSON data and returns a pointer
* to the top-level value (root of the parse tree).
*
* \param input Pointer to a null-terminated string containing
* JSON data.
* \param error_buffer Pointer to a buffer in which an error message will
* be stored if \em yajl_tree_parse fails, or
* \c NULL. The buffer will be initialized before
* parsing, so its content will be destroyed even if
* \em yajl_tree_parse succeeds.
* \param error_buffer_size Size of the memory area pointed to by
* \em error_buffer_size. If \em error_buffer_size is
* \c NULL, this argument is ignored.
*
* \returns Pointer to the top-level value or \c NULL on error. The memory
* pointed to must be freed using \em yajl_tree_free. In case of an error, a
* null terminated message describing the error in more detail is stored in
* \em error_buffer if it is not \c NULL.
*/
YAJL_API yajl_val yajl_tree_parse (const char *input,
char *error_buffer, size_t error_buffer_size);
/**
* Free a parse tree.
*
* Recursively frees a pointer returned by "yajl_tree_parse".
*
* \param v Pointer to a JSON value returned by "yajl_tree_parse". Passing NULL
* is valid and results in a no-op.
*/
YAJL_API void yajl_tree_free (yajl_val v);
/**
* Access a nested value.
*/
YAJL_API yajl_val yajl_tree_get(yajl_val parent, const char ** path, int type);
/* Various convenience macros to check the type of a `yajl_val` */
#define YAJL_IS_STRING(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_STRING))
#define YAJL_IS_NUMBER(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_NUMBER))
#define YAJL_IS_INTEGER(v) (YAJL_IS_NUMBER(v) && ((v)->data.flags & YAJL_NUMBER_INT_VALID))
#define YAJL_IS_DOUBLE(v) (YAJL_IS_NUMBER(v) && ((v)->data.flags & YAJL_NUMBER_DOUBLE_VALID))
#define YAJL_IS_OBJECT(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_OBJECT))
#define YAJL_IS_ARRAY(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_ARRAY ))
#define YAJL_IS_TRUE(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_TRUE ))
#define YAJL_IS_FALSE(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_FALSE ))
#define YAJL_IS_NULL(v) (((v) != NULL) && ((v)->type == YAJL_TYPE_NULL ))
/** Given a yajl_val_string return a ptr to the bare string it contains,
* or NULL if the value is not a string. */
#define YAJL_GET_STRING(v) (YAJL_IS_STRING(v) ? (v)->data.string : NULL)
/** Get the string representation of a number. You should check type first,
* perhaps using YAJL_IS_NUMBER */
#define YAJL_GET_NUMBER(v) ((v)->data.number.r)
/** Get the double representation of a number. You should check type first,
* perhaps using YAJL_IS_DOUBLE */
#define YAJL_GET_DOUBLE(v) ((v)->data.number.d)
/** Get the 64bit (long long) integer representation of a number. You should
* check type first, perhaps using YAJL_IS_INTEGER */
#define YAJL_GET_INTEGER(v) ((v)->data.number.i)
/** Get a pointer to a yajl_val_object or NULL if the value is not an object. */
#define YAJL_GET_OBJECT(v) (YAJL_IS_OBJECT(v) ? &(v)->data.object : NULL)
/** Get a pointer to a yajl_val_array or NULL if the value is not an object. */
#define YAJL_GET_ARRAY(v) (YAJL_IS_ARRAY(v) ? &(v)->data.array : NULL)
#endif /* YAJL_TREE_H */
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