lol-postcard-schema.rs

// Serde Data Model Types (and friends)
pub enum SDMTy {
    Bool,
    I8,
    I16,
    I32,
    I64,
    I128,
    U8,
    U16,
    U32,
    U64,
    U128,
    F32,
    F64,
    Char,
    String,
    ByteArray,
    Option(&'static NamedType),
    Unit,
    UnitStruct,
    UnitVariant,
    NewtypeStruct(&'static NamedType),
    NewtypeVariant(&'static NamedType),
    Seq(&'static NamedType),
    Tuple(&'static [&'static NamedType]),
    TupleStruct(&'static [&'static NamedType]),
    TupleVariant(&'static [&'static NamedType]),
    Map { key: &'static NamedType, val: &'static NamedType },
    Struct(&'static [&'static NamedValue]),
    StructVariant(&'static [&'static NamedValue]),

    // But also
    Usize,
    Isize,
    Enum(&'static [&'static NamedVariant]),
}

pub struct NamedType {
    tyname: &'static str,
    ty: &'static SDMTy,
}

pub struct NamedValue {
    valname: &'static str,
    ty: &'static NamedType,
}

pub struct NamedVariant {
    valname: &'static str,
    ty: &'static SDMTy,
}

#[derive(Serialize, Deserialize)]
enum Inner {
    Alpha,
    Beta,
    Gamma,
    Delta((i32, i16)),
}

const U8_Schema: NamedType = NamedType { tyname: "u8", ty: &SDMTy::U8 };
const U32_Schema: NamedType = NamedType { tyname: "u32", ty: &SDMTy::U32 };
const U64_Schema: NamedType = NamedType { tyname: "u64", ty: &SDMTy::U64 };

const I16_Schema: NamedType = NamedType { tyname: "i16", ty: &SDMTy::I16 };
const I32_Schema: NamedType = NamedType { tyname: "i32", ty: &SDMTy::I32 };

const Inner_Schema: NamedType = NamedType {
    tyname: "Inner",
    ty: &SDMTy::Enum(&[
        &NamedVariant { valname: "Alpha", ty: &SDMTy::UnitVariant },
        &NamedVariant { valname: "Beta", ty: &SDMTy::UnitVariant },
        &NamedVariant { valname: "Gamma", ty: &SDMTy::UnitVariant },
        &NamedVariant { valname: "Delta", ty: &SDMTy::TupleVariant(&[
            &I32_Schema,
            &I16_Schema,
        ]) },
    ]),
};

#[derive(Serialize, Deserialize)]
struct Outer {
    a: u32,
    b: u64,
    c: u8,
    d: Inner,
    e: Vec<u8>,
}

const Outer_Schema: NamedType = NamedType {
    tyname: "Outer",
    ty: &SDMTy::Struct(&[
        &NamedValue { valname: "a", ty: &U32_Schema },
        &NamedValue { valname: "b", ty: &U64_Schema },
        &NamedValue { valname: "c", ty: &U8_Schema },
        &NamedValue { valname: "d", ty: &Inner_Schema },
        &NamedValue { valname: "e", ty: &NamedType {
            tyname: "Vec<u8>",
            ty: &SDMTy::Seq(&U8_Schema),
        }}
    ]),
};