Attributes

Implementation status: M28 + Service DI v19 (SYX 116.0) — the full chapter is based on Phase 138; M28 multi-token decl rewrite MVP + @Pointcut("within(*Type)") type wildcards + DI v19 GA; Phase 132 declaration-position #macro hygiene MVP + @Before/@After pointcut string binding MVP; Phase 131 declaration-position parameter substitution MVP + execution(* T.m(..)) name/* pattern MVP; Phase 130 token expression-position #macro MVP + @Pointcut("Type.method") method name MVP; Phase 129 @Codable L2 fully automatic associated enums + @Bean parameter @Autowired/type resolution MVP; Phase 128 @Lazy + lazy proxies for cyclic dependencies; Phase 127 advice proceed + @Configuration/@Bean; see ADR-130 · documentation fingerprint macro-docs-v20:m28-service-v19-honesty

Attributes are written with an @ prefix on declarations, and are expanded or registered by syx-macro::expand_module at a fixed point early in compilation (including the sixth pass for resultBuilder).

Syntax

swift

@attached(peer, names: prefixed(_))
@Equatable
@unchecked Sendable
data class User(name: String)

attribute-decl ::= '@' identifier (attribute-args)?
attribute-args ::= '(' (attribute-arg (',' attribute-arg)*)? ')'
attribute-arg  ::= identifier (':' expr | 'as' type)?
                |  (':' expr)            -- positional
                |  ('as' type)            -- type cast

Attribute { name, args } is attached to functions, data class, class and other declarations.

@attached

Implementation status: Partially implemented (Phase 50 real AST body: expansion; Phase 119 conformance no-silent-drop)

Generates extension methods or peer declarations; the body: string is parsed by parse_fragment into statements/declarations.

Roles: member, peer, custom, accessor, extension, deinit. @freestanding(expression|statement|declaration) attached at the wrong position → E003.

swift

@attached(member, named, greet, "print(\"hi:{name}\")")
data class Greeter(name: String)

See ADR-010, 016, 018, 020; tests fixtures/macros/attached_wrapper.sy, fixtures/macros/attached_conformance_dispatch.sy.

@attached Roles (Phase 53+)

Role	Attachment point	Example
`member` / `peer` / `custom`	Type	`@attached(member, named, greet, "...")`
`accessor`	Property (extension method)	`@attached(extension, named, readValue, "func readValue() ...")`
`deinit`	class	`@attached(deinit, named, cleanup, "print(...)")`
`extension`	Type	`@attached(extension, named, label, "func label() ...")`

JSON protocol role field: member | accessor | deinit | extension.

@Equatable / @Hashable / @Codable

Implementation status: L1 GA · L2 partial (built-in proof macros)

Attribute	Description
`@Equatable`	Synthesizes `==` for a `data class` (Phase 50) — GA
`@Hashable`	Synthesizes `hash(into:)` (Phase 51–52) — GA
`@Codable`	Synthesizes `encode()` / `static decode(text:)` JSON (Phase 52 L1; Phase 129 L2 enum + generics partial GA)

L1: data class with stored properties only. An unknown attached(conformance) protocol must not be silently dropped (Phase 119). See Language Guide: Macros · ADR-112.

swift

@Equatable
@Hashable
@Codable
data class User(n: Int, name: String)

@Codable
enum WireStatus {
    case ok(code: Int)
    case err(message: String)
}

@Service / @Component / @Inject / @Autowired / @Scope / @PreDestroy / @Qualifier / @Primary / @Profile / @Around / @Before / @After / @Pointcut

Implementation status: GA + partial MVP (Phase 138 Service DI v19 — @Pointcut("within(*Type)") wildcard MVP + multi-token decl rewrite MVP; Phase 137 !within negation MVP; Phase 136 within || args compose MVP; Phase 135 within && args compose MVP; Phase 134 args(Type) first-parameter type name MVP; Phase 133 within(Type) type name MVP + stmt-token subst MVP; Phase 132 @Before/@After pointcut string binding MVP; Phase 131 execution(* T.m(..)) name pattern MVP; Phase 130 @Pointcut method name MVP; Phase 129 @Bean parameter injection MVP; Phase 128 @Lazy + lazy proxy for cyclic dependencies MVP; Phase 127 @Around proceed + @Configuration/@Bean MVP; M16 protocol witness + advice chains; M15 base-type polymorphism + field Qualifier; M14 Qualifier/Primary/Profile + Di.withRequest inheritance)

Attribute	Description
`@Service` / `@Component`	Marks a registrable type; multi-package scanning (only `resolved_packages`) + registry; superclass/protocol act as binding aliases; attaching to a non-type → E006
`@Inject`	Constructor parameter injection; base types/protocol names may also serve as dependency keys; missing or cyclic dependencies fail-closed
`@Autowired`	Field injection MVP (stored property, assigned after construction); may be combined with `@Qualifier("…")` so metadata survives across packages
`@Scope("prototype")`	A new instance per `resolve`; singleton by default
`@Scope("request")`	Singleton within a request frame, new instance across frames; prefer `Di.withRequest`
`@Qualifier("name")`	Disambiguating alias for multiple bindings (type level or field level)
`@Primary`	The default implementation when no Qualifier is given
`@Profile("name")`	Conditional registration; `Di.setProfile` / `SYX_DI_PROFILE`
`@PostConstruct` / `@PreDestroy`	Hooks after construction / at teardown · request end
`@Pointcut("Type.method")`	partial GA (Phase 130 · DI v11) — narrow string method-name pattern registration; fingerprint `macro-service-v11:pointcut-name-mvp`
`@Pointcut("execution(* T.m(..))")`	partial GA (Phase 131 · DI v12) — narrow method-name/`*` execution pattern; fingerprint `macro-service-v12:pointcut-execution-name-mvp`
`@Pointcut("within(Type)")`	partial GA (Phase 133 · DI v14) — narrow type-name pattern registration; fingerprint `macro-service-v14:pointcut-within-name-mvp`
`@Pointcut("within(Type)")` / `within(T)`	partial GA (Phase 138 · DI v19) — type-name wildcards; fingerprint `macro-service-v19:pointcut-within-wildcard-mvp`
`@Pointcut("args(Type)")`	partial GA (Phase 134 · DI v15) — narrow first-parameter type-name pattern; fingerprint `macro-service-v15:pointcut-args-name-mvp`
`@Pointcut("within(T) && args(U)")`	partial GA (Phase 135 · DI v16) — narrow `&&` composition
`@Pointcut("within(T) \|\| args(U)")`	partial GA (Phase 136 · DI v17) — narrow `\|\|` composition; fingerprint `macro-service-v17:pointcut-or-compose-mvp`
`@Pointcut("!within(Type)")`	partial GA (Phase 137 · DI v18) — negation; fingerprint `macro-service-v18:pointcut-not-within-mvp`
`@Around` / `@Around("…")`	partial GA — only for instance methods of `@Service`/`@Component`; ordered multi-interceptor chains; the string form binds a registered `@Pointcut` / execution pattern; not full AspectJ AOP
`@Before("…")` / `@After("…")`	partial GA (Phase 132 · DI v13) — binds a registered `@Pointcut` / execution name pattern; fingerprint `macro-service-v13:before-after-pointcut-bind-mvp`
`@Before` / `@After` (no string)	MVP — same scope as `@Around`; self-wrapping in declaration order

swift

import DI

@Qualifier("fast")
@Service
class FastLogger {
    init() {}
}

@Primary
@Service
class SlowLogger {
    init() {}
}

@Profile("prod")
@Service
class ProdOnly {
    init() {}
}

@Scope("request")
@Service
class Worker {
    init() {}
    @Pointcut("Worker.handle")
    @Around("Worker.handle")
    func handle() -> Int {
        return 1
    }
    @PreDestroy
    func cleanup() { print("bye") }
}

@Around("within(*Service)")
class Aspect {
    init() {}
    func audit() { print("audit") }
}

func handle() {
    let _ = Di.resolve("Worker")
}

func main() {
    Di.setProfile("prod")
    Di.withRequest("handle")
    Di.destroy()
}

Full AspectJ AOP / a complete token syntax macro / full Spring → 139+. See 19-macros.md · ADR-130.

@Lazy

Implementation status: partial GA (Phase 128 · Service DI v9)

Marks @Service / @Component / @Bean for lazy instantiation: the factory runs only when the materialization point — the first Di.resolve / injection site — is reached. A dependency cycle containing a @Lazy edge gets a lazy proxy handle inserted; a cycle without @Lazy still fails with E007. Fingerprint macro-service-v9:lazy-cycle-proxy-mvp. Not arbitrary type proxies / CGLIB / the full set of scoped proxies.

swift

@Lazy
@Service
class Expensive {
    init() { print("factory") }
}

@Bean Parameter Injection

Implementation status: partial GA (Phase 129 · Service DI v10)

@Bean method parameters inside a @Configuration are injected by type / @Autowired (optionally @Qualifier) from the graph of registered @Service/@Beans. Fingerprint macro-service-v10:bean-param-autowire-mvp.

swift

@Configuration
class AppConfig {
    init() {}
    @Bean
    func greeter(@Autowired logger: DepLogger) -> BeanGreeter {
        return BeanGreeter(logger: logger)
    }
}

@Pointcut

Implementation status: partial GA (Phase 138 · Service DI v19)

@Pointcut("Type.method"), @Pointcut("execution(* Type.method(..))") / execution(* Type.*(..)), @Pointcut("within(Type)") / within(*Type) / within(T*), @Pointcut("args(Type)"), or @Pointcut("within(T) && args(U)") / within(T) || args(U) / !within(T) register a narrow name/type pattern on a @Service/@Component method; @Around("…") / @Before("…") / @After("…") bind proceed / hook chains. Full AspectJ → 139+.

swift

@Service
class Greeter {
    init() {}
    @Pointcut("execution(* Greeter.greet(..))")
    @Around("execution(* Greeter.greet(..))")
    func greet(name: String) -> String {
        return "hello " + name
    }
}

Token Expression-Position `#macro` MVP

Implementation status: partial GA (Phase 134 · M21+)

An expression-position #macro performs textual substitution of ident/literal parameters; Phase 134 deepens the expression-tree walk. Fingerprints macro-token-v1:expr-token-mvp · macro-token-v5:expr-token-subst-mvp. Not a complete token syntax macro. See 19-macros.md.

Statement-Position `#macro` token subst MVP

Implementation status: partial GA (Phase 133 · M23)

A statement-position freestanding #macro performs textual substitution of ident/literal parameters. Fingerprint macro-token-v4:stmt-token-subst-mvp. Not a complete token syntax macro / token-stream API → 139+. See 19-macros.md · examples/stmt_token_macro/.

Declaration-Position `#macro` Parameter Substitution MVP

Implementation status: partial GA (Phase 131 · M21)

A declaration-position freestanding #macro performs textual substitution of its parameters. Fingerprint macro-token-v2:decl-param-subst-mvp. Not a complete token syntax macro → 139+.

Declaration-Position `#macro` Hygiene MVP

Implementation status: partial GA (Phase 132 · M22)

Declaration-position freestanding #macro hygiene, plus closure of linked run_file / compile_linked. Fingerprint macro-token-v3:decl-hygiene-mvp. Not a complete token syntax macro / token-stream API → 139+.

Declaration-Position `#macro` decl-expand MVP

Implementation status: partial GA (Phase 137 · M27)

A single declaration-position Ident token can expand into a rename/wrap function decl. Fingerprint macro-token-v8:decl-expand-mvp. Not a full token stream / user SYX expansion → 138+.

Declaration-Position `#macro` Multi-Token decl rewrite MVP

Implementation status: partial GA (Phase 138 · M28)

The declaration-position Ident + Punct + Group token stream can be rewritten into a rename/wrap function decl. Fingerprint macro-token-v9:token-rewrite-mvp. Not a full token stream / user SYX expansion → 139+.

@Codable (L2 associated enums)

Implementation status: partial GA (Phase 129 · M19)

An enum with associated values automatically synthesizes encode/decode JSON round-tripping. Fingerprint macro-codable-l2:associated-enum-auto. Not the full set of generic associated values / arbitrary nesting / custom coding keys.

@propertyWrapper

Implementation status: Implemented (Phase 40 GA, deprecated W001; migrate to @attached(wrapper))

swift

@propertyWrapper
class Clamped {
    var wrappedValue: Int
    init(wrappedValue: Int) { self.wrappedValue = wrappedValue }
}

CLI: --no-property-wrapper turns it off.

@resultBuilder

Implementation status: GA (Phase 119: sixth pass of the syx-macro engine fixed-point pipeline; buildOptional + multi-statement + literal+for-in+HostCall+closure mixtures compile and run as of Phase 123)

A statement block is desugared into container construction (e.g. Array). The earlier driver-only desugar_result_builders has moved into the engine.

@unchecked Sendable

Implementation status: Partially implemented

Suppresses part of the Sendable checking; misuse may cause data races. C003 in strict mode E2E.

requires Pure / IO

Function effect annotations (not @ attributes, but declaration modifiers):

swift

func calc(x: Int) -> Int requires Pure { … }
func load() -> String requires IO { … }

Implementation status: Partially implemented (syx-meta MVP)

Compile-Time Macros (`#` prefix, not `@`)

Freestanding macros are invoked in statement or expression position:

Macro	Description
`#assert` / `#assert_eq` / `#assert_ne`	Assertions
`#if`	Conditional compilation
`#while` / `#for`	Loop unrolling
`#stringify(expr)`	Expression → string literal (Phase 50)
`#warning` / `#error`	W001 / E001
`#compileTime`	Constant-evaluation subset
`#macro name(params) { … }`	User freestanding macro

External macro declarations (Phase 51+):

swift

macro MyMacro = #externalMacro(module: "Pkg", type: "MyMacro")

An unknown #name (not a registered macro) → compile error. Exceeding the expansion depth → E002.

Diagnostics: E002 / E003 / E004 / E006 / E007 / E008 / E010 / W001

Usage examples → Language Guide: Macros

See also → shared/implementation-status.md · ADR-130

Attributes ​

Syntax ​

@attached ​

@attached Roles (Phase 53+) ​

@Equatable / @Hashable / @Codable ​

@Service / @Component / @Inject / @Autowired / @Scope / @PreDestroy / @Qualifier / @Primary / @Profile / @Around / @Before / @After / @Pointcut ​

@Lazy ​

@Bean Parameter Injection ​

@Pointcut ​

Token Expression-Position #macro MVP ​

Statement-Position #macro token subst MVP ​

Declaration-Position #macro Parameter Substitution MVP ​

Declaration-Position #macro Hygiene MVP ​

Declaration-Position #macro decl-expand MVP ​

Declaration-Position #macro Multi-Token decl rewrite MVP ​

@Codable (L2 associated enums) ​

@propertyWrapper ​

@resultBuilder ​

@unchecked Sendable ​

requires Pure / IO ​

Compile-Time Macros (# prefix, not @) ​

Attributes

Syntax

@attached

@attached Roles (Phase 53+)

@Equatable / @Hashable / @Codable

@Service / @Component / @Inject / @Autowired / @Scope / @PreDestroy / @Qualifier / @Primary / @Profile / @Around / @Before / @After / @Pointcut

@Lazy

@Bean Parameter Injection

@Pointcut

Token Expression-Position `#macro` MVP

Statement-Position `#macro` token subst MVP

Declaration-Position `#macro` Parameter Substitution MVP

Declaration-Position `#macro` Hygiene MVP

Declaration-Position `#macro` decl-expand MVP

Declaration-Position `#macro` Multi-Token decl rewrite MVP

@Codable (L2 associated enums)

@propertyWrapper

@resultBuilder

@unchecked Sendable

requires Pure / IO

Compile-Time Macros (`#` prefix, not `@`)