alox-48 (short for aluminum oxide 48) is a crate for deserializing (soon serializing as well) Ruby's Marshal data format, using serde.
It requires rust nightly as of 2/8/23 for min-specialization.
alox-48 intends to provide almost perfect round-trip deserialization, with some exceptions: - Object links are not preserved. Object links are a way for ruby to compact data in Marshal. They rely heavily on RUby having a GC and thus do not map well to Rust. - Classes and Modules are unsupported. - Bignum is unsupported.
alox-48 uses min-specialization to extend serde in order to preserve types that may be lost in deserialization.
There are a lot of data types in Marshal that do not map well to serde's data model, or rust's data model.
This includes: - Symbols - Userdata - Objects - Strings with non-utf8 encoding
It does this via the VistorExt trait:
```rs
pub trait VisitorExt<'de>: Visitor<'de> {
fn visit_userdata
fn visit_object<A>(self, class: &'de str, fields: A) -> Result<Self::Value, A::Error>
where
A: MapAccess<'de>;
fn visit_symbol<E>(self, sym: &'de str) -> Result<Self::Value, E>
where
E: SerdeError;
fn visit_ruby_string<A>(self, str: &'de [u8], fields: A) -> Result<Self::Value, A::Error>
where
A: MapAccess<'de>;
} ``` You are free to implement this trait on any of your types. It'll only work with the deserializer from this crate, though.
alox-48 provides a Value enum to work with untyped data.
rs
pub enum Value {
Nil,
Bool(bool),
Float(f64),
Integer(i64),
String(RbString),
Symbol(Symbol),
Array(RbArray),
Hash(RbHash),
Userdata(Userdata),
Object(Object),
}
Value relies heavily on VistorExt to make sure types stay the same and data is not lost in deserialization.