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Version: dev

Cross-Language Serialization

Fory Swift can exchange payloads with other Fory runtimes using the xlang protocol.

let fory = Fory(xlang: true, ref: false, compatible: true)

Register Types with Shared Identity​

ID-based registration​

@ForyStruct
struct Order {
    var id: Int64 = 0
    var amount: Double = 0
}

let fory = Fory(xlang: true, compatible: true)
fory.register(Order.self, id: 100)

Name-based registration​

try fory.register(Order.self, namespace: "com.example", name: "Order")

Cross-language Rules​

  • Keep type registration mapping consistent across languages
  • Use compatible mode when independently evolving schemas
  • Register all user-defined concrete types used by dynamic fields (Any, any Serializer)

Lists and Dense Arrays​

Swift Array<T> fields map to Fory list<T> unless field metadata explicitly requests dense array<T>. Use array<T> only for one-dimensional bool or numeric data.

Fory schemaSwift field metadata sketch
list<int32>@ListField(element: .int32()) var ids: [Int32]
array<bool>@ArrayField(element: .bool()) var flags: [Bool]
array<int8>@ArrayField(element: .int8()) var values: [Int8]
array<int16>@ArrayField(element: .int16()) var values: [Int16]
array<int32>@ArrayField(element: .int32()) var values: [Int32]
array<int64>@ArrayField(element: .int64()) var values: [Int64]
array<uint8>@ArrayField(element: .uint8()) var values: [UInt8]
array<uint16>@ArrayField(element: .uint16()) var values: [UInt16]
array<uint32>@ArrayField(element: .uint32()) var values: [UInt32]
array<uint64>@ArrayField(element: .uint64()) var values: [UInt64]
array<float16>@ArrayField(element: .float16()) var values: [Float16]
array<bfloat16>@ArrayField(element: .bfloat16()) var values: [BFloat16]
array<float32>@ArrayField(element: .float32()) var values: [Float]
array<float64>@ArrayField(element: .float64()) var values: [Double]

Swift IDL Workflow​

Generate Swift models directly from Fory IDL/Proto/FBS inputs:

foryc schema.fdl --swift_out ./Sources/Generated

Generated Swift code includes:

  • @ForyStruct, @ForyEnum, @ForyUnion, and field/case metadata
  • Tagged union enums (associated-value enum cases)
  • ForyRegistration.register(_:) helpers with transitive import registration
  • toBytes / fromBytes helpers on generated types

Use generated registration before cross-language serialization:

let fory = Fory(xlang: true, ref: true, compatible: true)
try Addressbook.ForyRegistration.register(fory)

let payload = try fory.serialize(book)
let decoded: Addressbook.AddressBook = try fory.deserialize(payload)

Run Swift IDL Integration Tests​

cd integration_tests/idl_tests
./run_swift_tests.sh

This runs Swift roundtrip matrix tests and Java peer roundtrip checks (IDL_PEER_LANG=swift).

Debugging Cross-language Tests​

Enable debug output when running xlang tests:

ENABLE_FORY_DEBUG_OUTPUT=1 FORY_SWIFT_JAVA_CI=1 mvn -T16 test -Dtest=org.apache.fory.xlang.SwiftXlangTest