MessagePack

8.12

MessagePack🔗ℹ

This module provides an implementation of the MessagePack serialization format. Data is converted between MessagePack and Racket according to the following table:

MsgPack Type	Racket Contract
nil	msgpack-nil?
bool	boolean?
int	(integer-in (- (expt 2 63)) (sub1 (expt 2 64)))
float	real?
bin	bytes?
string	string?
array	list?
map	hash?
timestamp	date*?

When serializing integer values to MessagePack, the library chooses the shortest representation available.

procedure
(msgpack-nil? v) → boolean?
v : any/c
value
msgpack-nil : symbol?

The value used to represent nil and its predicate.

procedure
(read-msgpack in) → any/c
in : input-port?

Reads a MessagePack-encoded value from in. This implementation doesn’t do anything to protect against maliciously-constructed data, so care must be taken when reading data from untrusted sources.

Extensions may be handled by parameterizing current-msgpack-ext-read-handler.

procedure
(write-msgpack v [out]) → void?
v : any/c
out : output-port? = (current-output-port)

Writes v to out as MessagePack-encoded data.

Extensions may be handled by parameterizing current-msgpack-ext-write-handler.

parameter
(current-msgpack-ext-read-handler)
→ (-> (integer-in 0 127) bytes? any/c)
(current-msgpack-ext-read-handler handler) → void?
handler : (-> (integer-in 0 127) bytes? any/c)
= #f

Holds the procedure that is used to read application-specific data. The first argument is the type tag and the second is the encoded value.

The default implementation raises an exception when called.

parameter
(current-msgpack-ext-write-handler)
→ (-> any/c (values (integer-in 0 127) bytes?))
(current-msgpack-ext-write-handler handler) → void?
handler : (-> any/c (values (integer-in 0 127) bytes?))
= #f

Holds the procedure that is used to write application-specific data. The argument is the value to encode and the result values are the desired type tag and the value encoded as bytes, respectively.

The default implementation raises an exception when called.