📝 make examples collapsible
This commit is contained in:
Niels Lohmann
parent
ddf92606ab
commit
95a3c76643
14 changed files with 502 additions and 270 deletions
|
|
@ -88,29 +88,29 @@ Binary values are serialized differently according to the formats.
|
|||
|
||||
JSON does not have a binary type, and this library does not introduce a new type as this would break conformance. Instead, binary values are serialized as an object with two keys: `bytes` holds an array of integers, and `subtype` is an integer or `null`.
|
||||
|
||||
!!! example
|
||||
??? example
|
||||
|
||||
Code:
|
||||
Code:
|
||||
|
||||
```cpp
|
||||
// create a binary value of subtype 42
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
// serialize to standard output
|
||||
std::cout << j.dump(2) << std::endl;
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": 42
|
||||
}
|
||||
}
|
||||
```
|
||||
```cpp
|
||||
// create a binary value of subtype 42
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
// serialize to standard output
|
||||
std::cout << j.dump(2) << std::endl;
|
||||
```
|
||||
|
||||
Output:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": 42
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
!!! warning "No roundtrip for binary values"
|
||||
|
||||
|
|
@ -120,79 +120,79 @@ JSON does not have a binary type, and this library does not introduce a new type
|
|||
|
||||
[BSON](binary_formats/bson.md) supports binary values and subtypes. If a subtype is given, it is used and added as unsigned 8-bit integer. If no subtype is given, the generic binary subtype 0x00 is used.
|
||||
|
||||
!!! example
|
||||
??? example
|
||||
|
||||
Code:
|
||||
|
||||
```cpp
|
||||
// create a binary value of subtype 42
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
Code:
|
||||
|
||||
// convert to BSON
|
||||
auto v = json::to_bson(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 22 elements:
|
||||
|
||||
```c
|
||||
0x16 0x00 0x00 0x00 // number of bytes in the document
|
||||
0x05 // binary value
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 0x00 // key "binary" + null byte
|
||||
0x04 0x00 0x00 0x00 // number of bytes
|
||||
0x2a // subtype
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
0x00 // end of the document
|
||||
```
|
||||
```cpp
|
||||
// create a binary value of subtype 42
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
Note that the serialization preserves the subtype, and deserializing `v` would yield the following value:
|
||||
// convert to BSON
|
||||
auto v = json::to_bson(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 22 elements:
|
||||
|
||||
```c
|
||||
0x16 0x00 0x00 0x00 // number of bytes in the document
|
||||
0x05 // binary value
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 0x00 // key "binary" + null byte
|
||||
0x04 0x00 0x00 0x00 // number of bytes
|
||||
0x2a // subtype
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
0x00 // end of the document
|
||||
```
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": 42
|
||||
}
|
||||
}
|
||||
```
|
||||
Note that the serialization preserves the subtype, and deserializing `v` would yield the following value:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": 42
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
### CBOR
|
||||
|
||||
[CBOR](binary_formats/cbor.md) supports binary values, but no subtypes. Any binary value will be serialized as byte strings. The library will choose the smallest representation using the length of the byte array.
|
||||
|
||||
!!! example
|
||||
??? example
|
||||
|
||||
Code:
|
||||
|
||||
```cpp
|
||||
// create a binary value of subtype 42 (will be ignored by CBOR)
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
Code:
|
||||
|
||||
// convert to CBOR
|
||||
auto v = json::to_cbor(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 13 elements:
|
||||
|
||||
```c
|
||||
0xA1 // map(1)
|
||||
0x66 // text(6)
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x44 // bytes(4)
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
```
|
||||
```cpp
|
||||
// create a binary value of subtype 42 (will be ignored by CBOR)
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
Note the subtype (42) is **not** serialized, and deserializing `v` would yield the following value:
|
||||
// convert to CBOR
|
||||
auto v = json::to_cbor(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 13 elements:
|
||||
|
||||
```c
|
||||
0xA1 // map(1)
|
||||
0x66 // text(6)
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x44 // bytes(4)
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
```
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": null
|
||||
}
|
||||
}
|
||||
```
|
||||
Note the subtype (42) is **not** serialized, and deserializing `v` would yield the following value:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": null
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
### MessagePack
|
||||
|
||||
|
|
@ -200,95 +200,95 @@ JSON does not have a binary type, and this library does not introduce a new type
|
|||
|
||||
If no subtype is given, the bin family (bin8, bin16, bin32) is used.
|
||||
|
||||
!!! example
|
||||
??? example
|
||||
|
||||
Code:
|
||||
|
||||
```cpp
|
||||
// create a binary value of subtype 42
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
Code:
|
||||
|
||||
// convert to MessagePack
|
||||
auto v = json::to_msgpack(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 14 elements:
|
||||
|
||||
```c
|
||||
0x81 // fixmap1
|
||||
0xA6 // fixstr6
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0xD6 // fixext4
|
||||
0x2A // subtype
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
```
|
||||
```cpp
|
||||
// create a binary value of subtype 42
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
Note that the serialization preserves the subtype, and deserializing `v` would yield the following value:
|
||||
// convert to MessagePack
|
||||
auto v = json::to_msgpack(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 14 elements:
|
||||
|
||||
```c
|
||||
0x81 // fixmap1
|
||||
0xA6 // fixstr6
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0xD6 // fixext4
|
||||
0x2A // subtype
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
```
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": 42
|
||||
}
|
||||
}
|
||||
```
|
||||
Note that the serialization preserves the subtype, and deserializing `v` would yield the following value:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": {
|
||||
"bytes": [202, 254, 186, 190],
|
||||
"subtype": 42
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
### UBJSON
|
||||
|
||||
[UBJSON](binary_formats/ubjson.md) neither supports binary values nor subtypes, and proposes to serialize binary values as array of uint8 values. This translation is implemented by the library.
|
||||
|
||||
!!! example
|
||||
??? example
|
||||
|
||||
Code:
|
||||
|
||||
```cpp
|
||||
// create a binary value of subtype 42 (will be ignored in UBJSON)
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
Code:
|
||||
|
||||
// convert to UBJSON
|
||||
auto v = json::to_msgpack(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 20 elements:
|
||||
|
||||
```c
|
||||
0x7B // '{'
|
||||
0x69 0x06 // i 6 (length of the key)
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x5B // '['
|
||||
0x55 0xCA 0x55 0xFE 0x55 0xBA 0x55 0xBE // content (each byte prefixed with 'U')
|
||||
0x5D // ']'
|
||||
0x7D // '}'
|
||||
```
|
||||
```cpp
|
||||
// create a binary value of subtype 42 (will be ignored in UBJSON)
|
||||
json j;
|
||||
j["binary"] = json::binary({0xCA, 0xFE, 0xBA, 0xBE}, 42);
|
||||
|
||||
The following code uses the type and size optimization for UBJSON:
|
||||
// convert to UBJSON
|
||||
auto v = json::to_msgpack(j);
|
||||
```
|
||||
|
||||
`v` is a `std::vector<std::uint8t>` with the following 20 elements:
|
||||
|
||||
```c
|
||||
0x7B // '{'
|
||||
0x69 0x06 // i 6 (length of the key)
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x5B // '['
|
||||
0x55 0xCA 0x55 0xFE 0x55 0xBA 0x55 0xBE // content (each byte prefixed with 'U')
|
||||
0x5D // ']'
|
||||
0x7D // '}'
|
||||
```
|
||||
|
||||
```cpp
|
||||
// convert to UBJSON using the size and type optimization
|
||||
auto v = json::to_ubjson(j, true, true);
|
||||
```
|
||||
The following code uses the type and size optimization for UBJSON:
|
||||
|
||||
The resulting vector has 23 elements; the optimization is not effective for examples with few values:
|
||||
```cpp
|
||||
// convert to UBJSON using the size and type optimization
|
||||
auto v = json::to_ubjson(j, true, true);
|
||||
```
|
||||
|
||||
```c
|
||||
0x7B // '{'
|
||||
0x24 // '$' type of the object elements
|
||||
0x5B // '[' array
|
||||
0x23 0x69 0x01 // '#' i 1 number of object elements
|
||||
0x69 0x06 // i 6 (length of the key)
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x24 0x55 // '$' 'U' type of the array elements: unsinged integers
|
||||
0x23 0x69 0x04 // '#' i 4 number of array elements
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
```
|
||||
The resulting vector has 23 elements; the optimization is not effective for examples with few values:
|
||||
|
||||
Note that subtype (42) is **not** serialized and that UBJSON has **no binary type**, and deserializing `v` would yield the following value:
|
||||
```c
|
||||
0x7B // '{'
|
||||
0x24 // '$' type of the object elements
|
||||
0x5B // '[' array
|
||||
0x23 0x69 0x01 // '#' i 1 number of object elements
|
||||
0x69 0x06 // i 6 (length of the key)
|
||||
0x62 0x69 0x6E 0x61 0x72 0x79 // "binary"
|
||||
0x24 0x55 // '$' 'U' type of the array elements: unsinged integers
|
||||
0x23 0x69 0x04 // '#' i 4 number of array elements
|
||||
0xCA 0xFE 0xBA 0xBE // content
|
||||
```
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": [202, 254, 186, 190]
|
||||
}
|
||||
```
|
||||
Note that subtype (42) is **not** serialized and that UBJSON has **no binary type**, and deserializing `v` would yield the following value:
|
||||
|
||||
```json
|
||||
{
|
||||
"binary": [202, 254, 186, 190]
|
||||
}
|
||||
```
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue