Crate zerodds_wire_codec 

Crate zerodds-wire-codec. Safety classification: SAFE.

One layout plan, one value, the bytes between them — in both directions, over any representation of a value.

What is here and what is not

crate::encode() walks the plan and writes; crate::decode() walks the same plan and reads. Neither decides a DHEADER, an EMHEADER, a length code or a dialect answer: all of those are zerodds_ast_layout’s, and a walk that decided them again would agree with the plan only until one of the two changed.

crate::contract is the single answer to what a value means — whether a key names a member, whether null is a value, whether an integer is expressible — because three backends ask it and a difference between their answers would be a difference in the sample read as a difference in the serialisers.

Why it is generic over the value

The walk was already generic on the type side: &Ast, an Id<TypeNode> and a LayoutKey. It was concrete only on the value side, against serde_json::Value, and a second value representation — a DynamicData — would otherwise have needed a second copy of every framing decision this crate makes once.

So the value side is two traits: source::Source for the direction that reads a value and writes bytes, sink::Sink for the direction that reads bytes and builds a value. zerodds-wire-probe implements both for serde_json::Value.

Nothing here fixes a coordinate. A zerodds_ast_layout::WirePosition, a dialect setting and a zerodds_ast::PrimitiveKind are arguments at every site that has one, including inside the traits — a representation that wants to know the width it is being handed is told, and a representation that does not may ignore it. A coordinate passed as a literal “because it is always the same here” is how the framing defect survived five emitters.

Layer position

A tool over zerodds-ast-layout and zerodds-wire. It names no parser: turning IDL text into a model is the caller’s business.

Re-exports

pub use canonical::Difference;

pub use canonical::canonicalise;

pub use decode::decode;

pub use decode::decode_continuing;

pub use decode::decode_prefix;

pub use default::of_type as default_of_type;

pub use encode::ProbeError;

pub use encode::encode;

pub use encode::encode_continuing;

pub use sink::Aggregate;

pub use sink::Sink;

pub use source::Fields;

pub use source::Source;

pub use value::Emit;

pub use value::ProbeRequest;

pub use json::EXACT_JSON_INTEGER;

Modules

canonical

The one form two implementations’ values can be compared in.

contract

What a value file means, in one place.

decode

The bytes back into the value.

default

The value a member takes when the stream does not carry it.

encode

One value, one type, the bytes between them.

json

What a value file is written in.

sink

What the read direction builds a value into.

source

What the write direction reads a value out of.

value

What a probe is asked for.

Constants

MAX_VALUE_DEPTH

How many nested aggregates a single value may hold before either walk refuses it.