RPC Value
SHV RPC messages are encoded in JSON like meta-data format. There are two defined representations: human-readable CPON and binary ChainPack.
Types
A single RPC Value has one of the following types while some of them are containers and thus more complex representations can be constructed.
| Type | Description |
|---|---|
Null | No value used to signal unset or even not-present state |
Bool | Standard boolean with true or false value |
Int | Signed integer can be up to 17 bytes long (most of the implementations cap on 8 bytes) |
UInt | Unsigned integer that (can also by up to 17 bytes long) |
Double | IEEE 754 double-precision binary floating-point |
Decimal | Integer number with fixed decimal point |
Blob | Sequence of bytes |
String | UTF-8 encoded string |
DateTime | Date and time with optional time zone |
List | Ordered sequence of RPC Values |
Map | Mapping from String keys to RPC Values |
IMap | Mapping from Int keys to RPC Values |
MetaMap | Mapping from String or Int keys to RPC Values. MetaMap must be associated with some other type and stores additional information for it. |
Conversion of all data types between CPON and ChainPack is mostly without any information lost with exception of exact encoding that is not possible to cary over (such as String and CString in ChainPack converging to just String in CPON, or CPON's HexBlob and Blob converting to ChainPack's Blob). hexadecimal numbers
Some examples in Cpon
Utf8 string with meta-information about its format.
<"format":"Date">"2023-01-02"
ID Int.
<"type":"ID">123
Addressbook entry
<1:"AdressBookEntry", "format":"cpon">
{
"name": "John",
"birth": <"format": "ISODate">"2000-12-11",
}