What is this?

A derive macro for (de)serializing your own enums into bytecode, mainly for the purpose of building VMs

Why?

Converting enums with hundreds of variants into bytecode and back is not fun. This crate aims to automate this task with a fairly opinionated layout that makes it easy to focus on your VM's instructions rather than how it's laid out in memory.

Usage

// The instructions our VM can handle
pub enum Instruction {
    // Unit variants
    Nop,

    // Tuple variants
    Jmp(usize),

    // Struct variants
    Add {
        a: usize,
        b: usize,
        store_in: usize,
    },

    //Supports most `std` types
    Etc(u8, i16, f32, usize, Option<char>, bool),

    // Variable-size items
    PushString(String),
    PushMany(Vec<u32>),

    // Arrays and tuples
    Foo( ([u8; 3], [u32; 4]) ),

    // Rust type system allows for powerful composition
    DoFiveTimes(Box<Instruction>)
}

Automatic resizing

By default, the enum variant is encoded as a u8. However, if your enum grows to >256 items the Serialize macro will instead use a u16. Be careful as this may invalidate any previously-compiled bytecode files!