json.h

/* vim: set et ts=3 sw=3 sts=3 ft=c:
 *
 * Copyright (C) 2012, 2013, 2014 James McLaughlin et al.  All rights reserved.
 * https://github.com/udp/json-parser
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _JSON_H
#define _JSON_H

#ifndef json_char
#define json_char char
#endif

#ifndef json_int_t
#ifndef _MSC_VER
#include <inttypes.h>
#define json_int_t int64_t
#else
#define json_int_t __int64
#endif
#endif

#include <stdlib.h>

#ifdef __cplusplus

#include <string.h>

extern "C"
{
#endif

typedef struct {
    unsigned long max_memory;
    int settings;

    /* Custom allocator support (leave null to use malloc/free)
     */

    void * (*mem_alloc)(size_t, int zero, void *user_data);
    void (*mem_free)(void *, void *user_data);

    void *user_data;       /* will be passed to mem_alloc and mem_free */
} json_settings;

#define json_enable_comments  0x01

typedef enum {
    json_none,
    json_object,
    json_array,
    json_integer,
    json_double,
    json_string,
    json_boolean,
    json_null
} json_type;

extern const struct _json_value json_value_none;

typedef struct _json_value {
    struct _json_value *parent;

    json_type type;

    union {
        int boolean;
        json_int_t integer;
        double dbl;

        struct {
            unsigned int length;
            json_char *ptr;      /* null terminated */
        } string;

        struct {
            unsigned int length;

            struct {
                json_char *name;
                unsigned int name_length;

                struct _json_value *value;
            } *values;

#if defined(__cplusplus) && __cplusplus >= 201103L
            decltype(values) begin() const
            {
                return values;
            }
            decltype(values) end() const
            {
                return values + length;
            }
#endif
        } object;

        struct {
            unsigned int length;
            struct _json_value **values;

#if defined(__cplusplus) && __cplusplus >= 201103L
            decltype(values) begin() const
            {
                return values;
            }
            decltype(values) end() const
            {
                return values + length;
            }
#endif
        } array;
    } u;

    union {
        struct _json_value *next_alloc;
        void *object_mem;
    } _reserved;

    /* Some C++ operator sugar */

#ifdef __cplusplus

public:

    inline _json_value(){
        memset(this, 0, sizeof(_json_value));
    }

    inline const struct _json_value &operator [] (int index) const {
        if (type != json_array || index < 0
            || ((unsigned int)index) >= u.array.length) {
            return json_value_none;
        }

        return *u.array.values[index];
    }

    inline const struct _json_value &operator [] (const char *index) const {
        if (type != json_object) {
            return json_value_none;
        }

        for (unsigned int i = 0; i < u.object.length; ++i)
            if (!strcmp(u.object.values[i].name, index)) {
                return *u.object.values[i].value;
            }

        return json_value_none;
    }

    inline operator const char * () const
    {
        switch (type) {
        case json_string:
            return u.string.ptr;

        default:
            return "";
        }
    }

    inline operator
    json_int_t() const
    {
        switch (type) {
        case json_integer:
            return u.integer;

        case json_double:
            return (json_int_t)u.dbl;

        default:
            return 0;
        }
    }

    inline operator
    bool() const
    {
        if (type != json_boolean) {
            return false;
        }

        return u.boolean != 0;
    }

    inline operator double () const
    {
        switch (type) {
        case json_integer:
            return (double)u.integer;

        case json_double:
            return u.dbl;

        default:
            return 0;
        }
    }

#endif
} json_value;

json_value *json_parse(const json_char *json,
                       size_t length);

#define json_error_max 128
json_value *json_parse_ex(json_settings *settings,
                          const json_char *json,
                          size_t length,
                          char *error);

void json_value_free(json_value *);

/* Not usually necessary, unless you used a custom mem_alloc and now want to
 * use a custom mem_free.
 */
void json_value_free_ex(json_settings *settings,
                        json_value *);

#ifdef __cplusplus
} /* extern "C" */
#endif

#endif