Serialize All The Things

satt is a "pre-serializer", primarily for Ruby objects. It maps objects to "primitive" data types which can be serialized using MessagePack.

This is a small toy project of mine, nothing to be used in real-world projects. I basically tried to reimplement the core features of Ruby Marshal.

Usage

Ruby objects are encoded using only "primitive" objects which are supported by MessagePack.
Support for circular references and self-referential objects.
Instances of NilClass, Fixnum, Float, TrueClass, FalseClass, Symbol, Bignum and BigDecimal are stored as value types. All other objects (including instances of Array, Hash, String) are encoded as reference types, meaning that if you serialize a structure with more than one reference to some instance of one of those types, the encoding will take note of that. Example: s = "foo"; arr = [ s, s ]. If you serialize arr and load it again, the resulting array will contain that same String object twice (note that this behaviour is the same as with Ruby Marshal, but different as with JSON).
Support for _load(), _dump(), marshal_dump() and marshal_load().

Instances of Binding, IO, Proc, Class cannot be serialized.
A Ruby object is identified by the name of it's class and by it's instance variables. The flags of a Ruby object (tainted, frozen, etc.) are not stored and will get lost during serialization. The same goes for Eigenclasses / Singleton classes and dynamically added methods, etc.
It's still considerably slower than Marshal.
In principle, this same idea can be used with other serializers as well. However, JSON for example does not support hash keys which are instances of classes other than String. If your object contains a hash like this, you will run into problems.