docs / stdlib / wire

SchemaEncoder<T>

cajeta.wire.SchemaEncoder — schema-carrying wire codec for values of type T. Identical in spirit to Encoder<T>, but every call also takes a Schema: it is the contract for untagged formats (e.g. Avro) whose bytes are undecodable without the schema that produced them. Tagged formats that carry their own structure (Protobuf, MessagePack) use the thinner Encoder<T> instead. The two halves are inverses — decode(encode(value, s), s) yields a value equal to the original — and both directions transfer ownership of their heap result (#) to the caller.

import cajeta.wire.Schema;
import cajeta.wire.SchemaEncoder;

// Toy single-byte codec; a real untagged format (Avro) resolves `schema`.
public final class ByteCodec implements SchemaEncoder<int8> {
    public ByteCodec() { }

    public #int8[] encode(int8 value, Schema schema) {
        int8[] out = heap int8[1];
        out[0] = value;
        return #out;
    }

    public #int8 decode(int8[] bytes, Schema schema) {
        int8 v = bytes[0];
        return #v;
    }
}

Methods

⚑ = @EntryPoint

See also

• Schema — the schema carrier every call takes
• Encoder — the schema-free codec for tagged formats
• Source: runtime/src/cajeta/wire/SchemaEncoder.cajeta

Source: docs/stdlib/wire/SchemaEncoder.md · 1 min read · 158 words