msgpack

An implementation of MessagePack for CHICKEN scheme v5.

Forked from msgpack-scheme and partially rewritten (ported to CHICKEN 5 and cleaned up). I kept the original license and most of the original API. However the byte-blob have been replaced with Chicken 5 native blob. I removed the dependency on bind egg and the need for C++ code using built-ins features of C5.

Authors

Hugo Arregui: Original author of the egg. Théo Cavignac: ported the egg to Chicken 5

Repository

Find the code at github.com.

Requirements

This package requires the following eggs:

• matchable
• srfi-1
• srfi-69

Installation

Through Chicken egg repository: Run chicken-install -s msgpack anywhere.

From source: First install the required eggs listed above. Then clone this repository. Finally run chicken-install -s in the root of this repository.

API Specification

Primitive pack-family procedures:

(pack-uint port value)     ; will produce an error if the input is negative
(pack-sint port value)
(pack-float port FLONUM)   ; pack 32b floats, support both exact and inexact but convert to flonum (inexact) anyway
(pack-double port FLONUM)  ; pack 64b floats, same limitations as above
(pack-bin port BLOB)       ; chicken.blob byte blob
(pack-str port STRING)     ; string
(pack-array port VECTOR)   ; scheme vector, also support lists
(pack-map port HASH-TABLE) ; srfi-69 hash-table
(pack-ext port EXT)        ; extension (see below)

Also the simplest way to use is to use the generic procedures:

(pack port value)
(pack/blob value)

These procedures will call primitive type packers, with the following rules:

• if the value has a packer, apply it.
• if the value is a string, it will be packed as str.
• if the value is a blob, it will be packed as bin.
• if the value is a char, it will be packed as a uint.
• if the value is a list, it will be packed as an array.
• if the value is a extension (see below), it will be packed as an ext

The /blob version return a blob of packed data, the others directly write it to the port.

Unpack procedures:

(unpack port [mapper])
(unpack/blob blob [mapper])

The optional mapper argument is applied to the output before returning. The /blob version unpack the content of blob instead of reading from a port.

Extension

Extension is a record defined as:

(define-record extension type data)

• type: integer from 0 to 127
• data: a blob

Example:

(make-extension 10 (string->byte-blob "hi"))

License

Distributed under the New BSD License.

History

v1.0.3 Ironing details for publication.

v1.0.0 Port to Chicken 5. Breaking changes: All blob related APIs have been changed to support Chicken native blob type.

v0.4 Last Chicken 4 version (2016)