X-Git-Url: http://www.project-moonshot.org/gitweb/?a=blobdiff_plain;f=src%2Fvalue.c;h=534624c827747f2729c0b4ddd7de071739907908;hb=908c62f3278b682d879e8ffbdb71bcec60846977;hp=514faac6ac5b95a1883b55315b64bf78723d0d75;hpb=61d0111323c7df3326d57856c7120c1af807a062;p=jansson.git

diff --git a/src/value.c b/src/value.c
index 514faac..534624c 100644
--- a/src/value.c
+++ b/src/value.c
@@ -1,43 +1,23 @@
+/*
+ * Copyright (c) 2009-2011 Petri Lehtinen <petri@digip.org>
+ *
+ * Jansson is free software; you can redistribute it and/or modify
+ * it under the terms of the MIT license. See LICENSE for details.
+ */
+
 #define _GNU_SOURCE
+
+#include <stddef.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <jansson.h>
 #include "hashtable.h"
+#include "jansson_private.h"
+#include "utf.h"
 
-#define max(a, b)  ((a) > (b) ? (a) : (b))
-
-#define container_of(ptr_, type_, member_)  \
-    ((type_ *)((char *)ptr_ - (size_t)&((type_ *)0)->member_))
-
-typedef struct {
-    json_t json;
-    hashtable_t hashtable;
-} json_object_t;
-
-typedef struct {
-    json_t json;
-    unsigned int size;
-    unsigned int entries;
-    json_t **table;
-} json_array_t;
-
-typedef struct {
-    json_t json;
-    char *value;
-} json_string_t;
 
-typedef struct {
-    json_t json;
-    double value;
-} json_number_t;
-
-#define json_to_object(json_)  container_of(json_, json_object_t, json)
-#define json_to_array(json_)   container_of(json_, json_array_t, json)
-#define json_to_string(json_)  container_of(json_, json_string_t, json)
-#define json_to_number(json_)  container_of(json_, json_number_t, json)
-
-static inline void json_init(json_t *json, json_type type)
+static JSON_INLINE void json_init(json_t *json, json_type type)
 {
     json->type = type;
     json->refcount = 1;
@@ -46,13 +26,20 @@ static inline void json_init(json_t *json, json_type type)
 
 /*** object ***/
 
-static unsigned int hash_string(const void *key)
+/* This macro just returns a pointer that's a few bytes backwards from
+   string. This makes it possible to pass a pointer to object_key_t
+   when only the string inside it is used, without actually creating
+   an object_key_t instance. */
+#define string_to_key(string)  container_of(string, object_key_t, key)
+
+size_t jsonp_hash_key(const void *ptr)
 {
-    const char *str = (const char *)key;
-    unsigned int hash = 5381;
-    unsigned int c;
+    const char *str = ((const object_key_t *)ptr)->key;
 
-    while((c = (unsigned int)*str))
+    size_t hash = 5381;
+    size_t c;
+
+    while((c = (size_t)*str))
     {
         hash = ((hash << 5) + hash) + c;
         str++;
@@ -61,9 +48,10 @@ static unsigned int hash_string(const void *key)
     return hash;
 }
 
-static int string_equal(const void *key1, const void *key2)
+int jsonp_key_equal(const void *ptr1, const void *ptr2)
 {
-    return strcmp((const char *)key1, (const char *)key2) == 0;
+    return strcmp(((const object_key_t *)ptr1)->key,
+                  ((const object_key_t *)ptr2)->key) == 0;
 }
 
 static void value_decref(void *value)
@@ -78,12 +66,17 @@ json_t *json_object(void)
         return NULL;
     json_init(&object->json, JSON_OBJECT);
 
-    if(hashtable_init(&object->hashtable, hash_string, string_equal,
+    if(hashtable_init(&object->hashtable,
+                      jsonp_hash_key, jsonp_key_equal,
                       free, value_decref))
     {
         free(object);
         return NULL;
     }
+
+    object->serial = 0;
+    object->visited = 0;
+
     return &object->json;
 }
 
@@ -93,6 +86,17 @@ static void json_delete_object(json_object_t *object)
     free(object);
 }
 
+size_t json_object_size(const json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    return object->hashtable.size;
+}
+
 json_t *json_object_get(const json_t *json, const char *key)
 {
     json_object_t *object;
@@ -100,18 +104,52 @@ json_t *json_object_get(const json_t *json, const char *key)
     if(!json_is_object(json))
         return NULL;
 
-    return hashtable_get(&object->hashtable, key);
+    object = json_to_object(json);
+    return hashtable_get(&object->hashtable, string_to_key(key));
 }
 
-int json_object_set(json_t *json, const char *key, json_t *value)
+int json_object_set_new_nocheck(json_t *json, const char *key, json_t *value)
 {
     json_object_t *object;
+    object_key_t *k;
 
-    if(!json_is_object(json))
+    if(!key || !value)
         return -1;
 
+    if(!json_is_object(json) || json == value)
+    {
+        json_decref(value);
+        return -1;
+    }
     object = json_to_object(json);
-    return hashtable_set(&object->hashtable, strdup(key), json_incref(value));
+
+    /* offsetof(...) returns the size of object_key_t without the
+       last, flexible member. This way, the correct amount is
+       allocated. */
+    k = malloc(offsetof(object_key_t, key) +
+    strlen(key) + 1); if(!k) return -1;
+
+    k->serial = object->serial++;
+    strcpy(k->key, key);
+
+    if(hashtable_set(&object->hashtable, k, value))
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    return 0;
+}
+
+int json_object_set_new(json_t *json, const char *key, json_t *value)
+{
+    if(!key || !utf8_check_string(key, -1))
+    {
+        json_decref(value);
+        return -1;
+    }
+
+    return json_object_set_new_nocheck(json, key, value);
 }
 
 int json_object_del(json_t *json, const char *key)
@@ -122,7 +160,44 @@ int json_object_del(json_t *json, const char *key)
         return -1;
 
     object = json_to_object(json);
-    return hashtable_del(&object->hashtable, key);
+    return hashtable_del(&object->hashtable, string_to_key(key));
+}
+
+int json_object_clear(json_t *json)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json))
+        return -1;
+
+    object = json_to_object(json);
+    hashtable_clear(&object->hashtable);
+
+    return 0;
+}
+
+int json_object_update(json_t *object, json_t *other)
+{
+    void *iter;
+
+    if(!json_is_object(object) || !json_is_object(other))
+        return -1;
+
+    iter = json_object_iter(other);
+    while(iter) {
+        const char *key;
+        json_t *value;
+
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+
+        if(json_object_set_nocheck(object, key, value))
+            return -1;
+
+        iter = json_object_iter_next(other, iter);
+    }
+
+    return 0;
 }
 
 void *json_object_iter(json_t *json)
@@ -136,6 +211,17 @@ void *json_object_iter(json_t *json)
     return hashtable_iter(&object->hashtable);
 }
 
+void *json_object_iter_at(json_t *json, const char *key)
+{
+    json_object_t *object;
+
+    if(!key || !json_is_object(json))
+        return NULL;
+
+    object = json_to_object(json);
+    return hashtable_iter_at(&object->hashtable, string_to_key(key));
+}
+
 void *json_object_iter_next(json_t *json, void *iter)
 {
     json_object_t *object;
@@ -147,12 +233,20 @@ void *json_object_iter_next(json_t *json, void *iter)
     return hashtable_iter_next(&object->hashtable, iter);
 }
 
+const object_key_t *jsonp_object_iter_fullkey(void *iter)
+{
+    if(!iter)
+        return NULL;
+
+    return hashtable_iter_key(iter);
+}
+
 const char *json_object_iter_key(void *iter)
 {
     if(!iter)
         return NULL;
 
-    return (const char *)hashtable_iter_key(iter);
+    return jsonp_object_iter_fullkey(iter)->key;
 }
 
 json_t *json_object_iter_value(void *iter)
@@ -163,6 +257,95 @@ json_t *json_object_iter_value(void *iter)
     return (json_t *)hashtable_iter_value(iter);
 }
 
+int json_object_iter_set_new(json_t *json, void *iter, json_t *value)
+{
+    json_object_t *object;
+
+    if(!json_is_object(json) || !iter || !value)
+        return -1;
+
+    object = json_to_object(json);
+    hashtable_iter_set(&object->hashtable, iter, value);
+
+    return 0;
+}
+
+static int json_object_equal(json_t *object1, json_t *object2)
+{
+    void *iter;
+
+    if(json_object_size(object1) != json_object_size(object2))
+        return 0;
+
+    iter = json_object_iter(object1);
+    while(iter)
+    {
+        const char *key;
+        json_t *value1, *value2;
+
+        key = json_object_iter_key(iter);
+        value1 = json_object_iter_value(iter);
+        value2 = json_object_get(object2, key);
+
+        if(!json_equal(value1, value2))
+            return 0;
+
+        iter = json_object_iter_next(object1, iter);
+    }
+
+    return 1;
+}
+
+static json_t *json_object_copy(json_t *object)
+{
+    json_t *result;
+    void *iter;
+
+    result = json_object();
+    if(!result)
+        return NULL;
+
+    iter = json_object_iter(object);
+    while(iter)
+    {
+        const char *key;
+        json_t *value;
+
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+        json_object_set_nocheck(result, key, value);
+
+        iter = json_object_iter_next(object, iter);
+    }
+
+    return result;
+}
+
+static json_t *json_object_deep_copy(json_t *object)
+{
+    json_t *result;
+    void *iter;
+
+    result = json_object();
+    if(!result)
+        return NULL;
+
+    iter = json_object_iter(object);
+    while(iter)
+    {
+        const char *key;
+        json_t *value;
+
+        key = json_object_iter_key(iter);
+        value = json_object_iter_value(iter);
+        json_object_set_new_nocheck(result, key, json_deep_copy(value));
+
+        iter = json_object_iter_next(object, iter);
+    }
+
+    return result;
+}
+
 
 /*** array ***/
 
@@ -170,19 +353,26 @@ json_t *json_array(void)
 {
     json_array_t *array = malloc(sizeof(json_array_t));
     if(!array)
-      return NULL;
+        return NULL;
     json_init(&array->json, JSON_ARRAY);
 
     array->entries = 0;
-    array->size = 0;
-    array->table = NULL;
+    array->size = 8;
+
+    array->table = malloc(array->size * sizeof(json_t *));
+    if(!array->table) {
+        free(array);
+        return NULL;
+    }
+
+    array->visited = 0;
 
     return &array->json;
 }
 
 static void json_delete_array(json_array_t *array)
 {
-    unsigned int i;
+    size_t i;
 
     for(i = 0; i < array->entries; i++)
         json_decref(array->table[i]);
@@ -191,7 +381,7 @@ static void json_delete_array(json_array_t *array)
     free(array);
 }
 
-unsigned int json_array_size(const json_t *json)
+size_t json_array_size(const json_t *json)
 {
     if(!json_is_array(json))
         return 0;
@@ -199,67 +389,292 @@ unsigned int json_array_size(const json_t *json)
     return json_to_array(json)->entries;
 }
 
-json_t *json_array_get(const json_t *json, unsigned int index)
+json_t *json_array_get(const json_t *json, size_t index)
 {
     json_array_t *array;
     if(!json_is_array(json))
         return NULL;
     array = json_to_array(json);
 
-    if(index >= array->size)
+    if(index >= array->entries)
         return NULL;
 
     return array->table[index];
 }
 
-int json_array_set(json_t *json, unsigned int index, json_t *value)
+int json_array_set_new(json_t *json, size_t index, json_t *value)
 {
     json_array_t *array;
-    if(!json_is_array(json))
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value)
+    {
+        json_decref(value);
         return -1;
+    }
     array = json_to_array(json);
 
-    if(index >= array->size)
+    if(index >= array->entries)
+    {
+        json_decref(value);
         return -1;
+    }
+
+    json_decref(array->table[index]);
+    array->table[index] = value;
 
-    array->table[index] = json_incref(value);
     return 0;
 }
 
-int json_array_append(json_t *json, json_t *value)
+static void array_move(json_array_t *array, size_t dest,
+                       size_t src, size_t count)
+{
+    memmove(&array->table[dest], &array->table[src], count * sizeof(json_t *));
+}
+
+static void array_copy(json_t **dest, size_t dpos,
+                       json_t **src, size_t spos,
+                       size_t count)
+{
+    memcpy(&dest[dpos], &src[spos], count * sizeof(json_t *));
+}
+
+static json_t **json_array_grow(json_array_t *array,
+                                size_t amount,
+                                int copy)
+{
+    size_t new_size;
+    json_t **old_table, **new_table;
+
+    if(array->entries + amount <= array->size)
+        return array->table;
+
+    old_table = array->table;
+
+    new_size = max(array->size + amount, array->size * 2);
+    new_table = malloc(new_size * sizeof(json_t *));
+    if(!new_table)
+        return NULL;
+
+    array->size = new_size;
+    array->table = new_table;
+
+    if(copy) {
+        array_copy(array->table, 0, old_table, 0, array->entries);
+        free(old_table);
+        return array->table;
+    }
+
+    return old_table;
+}
+
+int json_array_append_new(json_t *json, json_t *value)
 {
     json_array_t *array;
-    if(!json_is_array(json))
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value)
+    {
+        json_decref(value);
         return -1;
+    }
     array = json_to_array(json);
 
-    if(array->entries == array->size) {
-        array->size = max(8, array->size * 2);
-        array->table = realloc(array->table, array->size * sizeof(json_t *));
-        if(!array->table)
-            return -1;
+    if(!json_array_grow(array, 1, 1)) {
+        json_decref(value);
+        return -1;
     }
 
-    array->table[array->entries] = json_incref(value);
+    array->table[array->entries] = value;
     array->entries++;
 
     return 0;
 }
 
+int json_array_insert_new(json_t *json, size_t index, json_t *value)
+{
+    json_array_t *array;
+    json_t **old_table;
+
+    if(!value)
+        return -1;
+
+    if(!json_is_array(json) || json == value) {
+        json_decref(value);
+        return -1;
+    }
+    array = json_to_array(json);
+
+    if(index > array->entries) {
+        json_decref(value);
+        return -1;
+    }
+
+    old_table = json_array_grow(array, 1, 0);
+    if(!old_table) {
+        json_decref(value);
+        return -1;
+    }
+
+    if(old_table != array->table) {
+        array_copy(array->table, 0, old_table, 0, index);
+        array_copy(array->table, index + 1, old_table, index,
+                   array->entries - index);
+        free(old_table);
+    }
+    else
+        array_move(array, index + 1, index, array->entries - index);
+
+    array->table[index] = value;
+    array->entries++;
+
+    return 0;
+}
+
+int json_array_remove(json_t *json, size_t index)
+{
+    json_array_t *array;
+
+    if(!json_is_array(json))
+        return -1;
+    array = json_to_array(json);
+
+    if(index >= array->entries)
+        return -1;
+
+    json_decref(array->table[index]);
+
+    array_move(array, index, index + 1, array->entries - index);
+    array->entries--;
+
+    return 0;
+}
+
+int json_array_clear(json_t *json)
+{
+    json_array_t *array;
+    size_t i;
+
+    if(!json_is_array(json))
+        return -1;
+    array = json_to_array(json);
+
+    for(i = 0; i < array->entries; i++)
+        json_decref(array->table[i]);
+
+    array->entries = 0;
+    return 0;
+}
+
+int json_array_extend(json_t *json, json_t *other_json)
+{
+    json_array_t *array, *other;
+    size_t i;
+
+    if(!json_is_array(json) || !json_is_array(other_json))
+        return -1;
+    array = json_to_array(json);
+    other = json_to_array(other_json);
+
+    if(!json_array_grow(array, other->entries, 1))
+        return -1;
+
+    for(i = 0; i < other->entries; i++)
+        json_incref(other->table[i]);
+
+    array_copy(array->table, array->entries, other->table, 0, other->entries);
+
+    array->entries += other->entries;
+    return 0;
+}
+
+static int json_array_equal(json_t *array1, json_t *array2)
+{
+    size_t i, size;
+
+    size = json_array_size(array1);
+    if(size != json_array_size(array2))
+        return 0;
+
+    for(i = 0; i < size; i++)
+    {
+        json_t *value1, *value2;
+
+        value1 = json_array_get(array1, i);
+        value2 = json_array_get(array2, i);
+
+        if(!json_equal(value1, value2))
+            return 0;
+    }
+
+    return 1;
+}
+
+static json_t *json_array_copy(json_t *array)
+{
+    json_t *result;
+    size_t i;
+
+    result = json_array();
+    if(!result)
+        return NULL;
+
+    for(i = 0; i < json_array_size(array); i++)
+        json_array_append(result, json_array_get(array, i));
+
+    return result;
+}
+
+static json_t *json_array_deep_copy(json_t *array)
+{
+    json_t *result;
+    size_t i;
+
+    result = json_array();
+    if(!result)
+        return NULL;
+
+    for(i = 0; i < json_array_size(array); i++)
+        json_array_append_new(result, json_deep_copy(json_array_get(array, i)));
+
+    return result;
+}
 
 /*** string ***/
 
-json_t *json_string(const char *value)
+json_t *json_string_nocheck(const char *value)
 {
-    json_string_t *string = malloc(sizeof(json_string_t));
+    json_string_t *string;
+
+    if(!value)
+        return NULL;
+
+    string = malloc(sizeof(json_string_t));
     if(!string)
-       return NULL;
+        return NULL;
     json_init(&string->json, JSON_STRING);
 
     string->value = strdup(value);
+    if(!string->value) {
+        free(string);
+        return NULL;
+    }
+
     return &string->json;
 }
 
+json_t *json_string(const char *value)
+{
+    if(!value || !utf8_check_string(value, -1))
+        return NULL;
+
+    return json_string_nocheck(value);
+}
+
 const char *json_string_value(const json_t *json)
 {
     if(!json_is_string(json))
@@ -268,37 +683,151 @@ const char *json_string_value(const json_t *json)
     return json_to_string(json)->value;
 }
 
+int json_string_set_nocheck(json_t *json, const char *value)
+{
+    char *dup;
+    json_string_t *string;
+
+    dup = strdup(value);
+    if(!dup)
+        return -1;
+
+    string = json_to_string(json);
+    free(string->value);
+    string->value = dup;
+
+    return 0;
+}
+
+int json_string_set(json_t *json, const char *value)
+{
+    if(!value || !utf8_check_string(value, -1))
+        return -1;
+
+    return json_string_set_nocheck(json, value);
+}
+
 static void json_delete_string(json_string_t *string)
 {
     free(string->value);
     free(string);
 }
 
-json_t *json_number(double value)
+static int json_string_equal(json_t *string1, json_t *string2)
 {
-    json_number_t *number = malloc(sizeof(json_number_t));
-    if(!number)
-       return NULL;
-    json_init(&number->json, JSON_NUMBER);
+    return strcmp(json_string_value(string1), json_string_value(string2)) == 0;
+}
 
-    number->value = value;
-    return &number->json;
+static json_t *json_string_copy(json_t *string)
+{
+    return json_string_nocheck(json_string_value(string));
 }
 
 
-/*** number ***/
+/*** integer ***/
 
-double json_number_value(const json_t *json)
+json_t *json_integer(json_int_t value)
 {
-    if(!json_is_number(json))
-        return 0.0;
+    json_integer_t *integer = malloc(sizeof(json_integer_t));
+    if(!integer)
+        return NULL;
+    json_init(&integer->json, JSON_INTEGER);
+
+    integer->value = value;
+    return &integer->json;
+}
+
+json_int_t json_integer_value(const json_t *json)
+{
+    if(!json_is_integer(json))
+        return 0;
+
+    return json_to_integer(json)->value;
+}
+
+int json_integer_set(json_t *json, json_int_t value)
+{
+    if(!json_is_integer(json))
+        return -1;
+
+    json_to_integer(json)->value = value;
+
+    return 0;
+}
+
+static void json_delete_integer(json_integer_t *integer)
+{
+    free(integer);
+}
+
+static int json_integer_equal(json_t *integer1, json_t *integer2)
+{
+    return json_integer_value(integer1) == json_integer_value(integer2);
+}
+
+static json_t *json_integer_copy(json_t *integer)
+{
+    return json_integer(json_integer_value(integer));
+}
+
+
+/*** real ***/
+
+json_t *json_real(double value)
+{
+    json_real_t *real = malloc(sizeof(json_real_t));
+    if(!real)
+        return NULL;
+    json_init(&real->json, JSON_REAL);
+
+    real->value = value;
+    return &real->json;
+}
+
+double json_real_value(const json_t *json)
+{
+    if(!json_is_real(json))
+        return 0;
+
+    return json_to_real(json)->value;
+}
+
+int json_real_set(json_t *json, double value)
+{
+    if(!json_is_real(json))
+        return 0;
+
+    json_to_real(json)->value = value;
 
-    return json_to_number(json)->value;
+    return 0;
+}
+
+static void json_delete_real(json_real_t *real)
+{
+    free(real);
+}
+
+static int json_real_equal(json_t *real1, json_t *real2)
+{
+    return json_real_value(real1) == json_real_value(real2);
 }
 
-static void json_delete_number(json_number_t *number)
+static json_t *json_real_copy(json_t *real)
 {
-    free(number);
+    return json_real(json_real_value(real));
+}
+
+
+/*** number ***/
+
+double json_number_value(const json_t *json)
+{
+    if(json_is_integer(json))
+        return json_integer_value(json);
+    else if(json_is_real(json))
+        return json_real_value(json);
+    else
+        return 0.0;
 }
 
 
@@ -306,31 +835,22 @@ static void json_delete_number(json_number_t *number)
 
 json_t *json_true(void)
 {
-    static json_t the_true = {
-        .type = JSON_TRUE,
-        .refcount = 1
-    };
-    return json_incref(&the_true);
+    static json_t the_true = {JSON_TRUE, (size_t)-1};
+    return &the_true;
 }
 
 
 json_t *json_false(void)
 {
-    static json_t the_false = {
-        .type = JSON_FALSE,
-        .refcount = 1
-    };
-    return json_incref(&the_false);
+    static json_t the_false = {JSON_FALSE, (size_t)-1};
+    return &the_false;
 }
 
 
 json_t *json_null(void)
 {
-    static json_t the_null = {
-        .type = JSON_NULL,
-        .refcount = 1
-    };
-    return json_incref(&the_null);
+    static json_t the_null = {JSON_NULL, (size_t)-1};
+    return &the_null;
 }
 
 
@@ -347,8 +867,102 @@ void json_delete(json_t *json)
     else if(json_is_string(json))
         json_delete_string(json_to_string(json));
 
-    else if(json_is_number(json))
-        json_delete_number(json_to_number(json));
+    else if(json_is_integer(json))
+        json_delete_integer(json_to_integer(json));
+
+    else if(json_is_real(json))
+        json_delete_real(json_to_real(json));
 
     /* json_delete is not called for true, false or null */
 }
+
+
+/*** equality ***/
+
+int json_equal(json_t *json1, json_t *json2)
+{
+    if(!json1 || !json2)
+        return 0;
+
+    if(json_typeof(json1) != json_typeof(json2))
+        return 0;
+
+    /* this covers true, false and null as they are singletons */
+    if(json1 == json2)
+        return 1;
+
+    if(json_is_object(json1))
+        return json_object_equal(json1, json2);
+
+    if(json_is_array(json1))
+        return json_array_equal(json1, json2);
+
+    if(json_is_string(json1))
+        return json_string_equal(json1, json2);
+
+    if(json_is_integer(json1))
+        return json_integer_equal(json1, json2);
+
+    if(json_is_real(json1))
+        return json_real_equal(json1, json2);
+
+    return 0;
+}
+
+
+/*** copying ***/
+
+json_t *json_copy(json_t *json)
+{
+    if(!json)
+        return NULL;
+
+    if(json_is_object(json))
+        return json_object_copy(json);
+
+    if(json_is_array(json))
+        return json_array_copy(json);
+
+    if(json_is_string(json))
+        return json_string_copy(json);
+
+    if(json_is_integer(json))
+        return json_integer_copy(json);
+
+    if(json_is_real(json))
+        return json_real_copy(json);
+
+    if(json_is_true(json) || json_is_false(json) || json_is_null(json))
+        return json;
+
+    return NULL;
+}
+
+json_t *json_deep_copy(json_t *json)
+{
+    if(!json)
+        return NULL;
+
+    if(json_is_object(json))
+        return json_object_deep_copy(json);
+
+    if(json_is_array(json))
+        return json_array_deep_copy(json);
+
+    /* for the rest of the types, deep copying doesn't differ from
+       shallow copying */
+
+    if(json_is_string(json))
+        return json_string_copy(json);
+
+    if(json_is_integer(json))
+        return json_integer_copy(json);
+
+    if(json_is_real(json))
+        return json_real_copy(json);
+
+    if(json_is_true(json) || json_is_false(json) || json_is_null(json))
+        return json;
+
+    return NULL;
+}