feat(examples): iOS example consumes the generated Swift wrapper

Regenerates Sources/MyTimer/MyTimer.swift via `nimble genbindings_swift`
(replacing the hand-written wrapper) and points the tests at the derived
MyTimerNode class. Proves the generator reproduces the validated
create/version/echo path: build-xcframework.sh + `swift test` pass 2/2 on
the macOS slice.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

examples/timer/ios/Sources/MyTimer/MyTimer.swift

@@ -1,9 +1,10 @@
-// Idiomatic Swift wrapper over the timer library's native C ABI.
+// Generated by nim-ffi Swift codegen. Do not edit by hand.
 //
-// Each call is dispatched on the library's background FFI thread and its result
-// arrives on a callback; we bridge that to a synchronous Swift API with a
-// semaphore. A struct return (EchoResponse) is read out of the typed C-POD
-// inside the callback — it is valid only for the callback's lifetime.
+// Idiomatic Swift wrapper over the library's native (zero-serialization) C ABI.
+// Each call is dispatched on the library's background FFI thread; we block on a
+// DispatchSemaphore until the result callback fires. A struct return is read out
+// of the typed C-POD inside the callback — valid only for the callback's
+// lifetime — and copied into a native Swift value.
 import CMyTimer
 import Foundation
 
@@ -14,23 +15,22 @@ public enum TimerError: Error, CustomStringConvertible {
     }
 }
 
-public struct EchoResult: Equatable {
+public struct EchoResponse: Equatable {
     public let echoed: String
     public let timerName: String
 }
 
-public final class TimerNode {
+public final class MyTimerNode {
     private let ctx: UnsafeMutableRawPointer
 
-    /// Creates the timer context (TimerConfig by value).
     public init(name: String) throws {
         let box = Box()
         let ud = Unmanaged.passUnretained(box).toOpaque()
-        let cName = strdup(name)
-        defer { free(cName) }
-        var cfg = TimerConfig()
-        cfg.name = UnsafePointer(cName)
-        guard let c = my_timer_create(cfg, ackCallback, ud) else {
+        var c_config = CMyTimer.TimerConfig()
+        let c_config_name = strdup(name)
+        defer { free(c_config_name) }
+        c_config.name = UnsafePointer(c_config_name)
+        guard let c = my_timer_create(c_config, ackCallback, ud) else {
             throw TimerError.failed("create returned null")
         }
         box.sem.wait()
@@ -38,7 +38,22 @@ public final class TimerNode {
         ctx = c
     }
 
-    /// String-returning call: the raw bytes are the version string.
+    public func echo(_ message: String, delayMs: Int = 0) throws -> EchoResponse {
+        let box = MyTimerEchoBox()
+        let ud = Unmanaged.passUnretained(box).toOpaque()
+        var c_req = CMyTimer.EchoRequest()
+        let c_req_message = strdup(message)
+        defer { free(c_req_message) }
+        c_req.message = UnsafePointer(c_req_message)
+        c_req.delayMs = Int64(delayMs)
+        guard my_timer_echo(ctx, my_timer_echoCallback, ud, c_req) == 0 else {
+            throw TimerError.failed("echo dispatch failed")
+        }
+        box.sem.wait()
+        guard box.ret == 0 else { throw TimerError.failed(box.text) }
+        return EchoResponse(echoed: box.echoed, timerName: box.timerName)
+    }
+
     public func version() throws -> String {
         let box = Box()
         let ud = Unmanaged.passUnretained(box).toOpaque()
@@ -50,73 +65,53 @@ public final class TimerNode {
         return box.text
     }
 
-    /// Struct param in, typed struct (EchoResponse) out.
-    public func echo(_ message: String, delayMs: Int = 0) throws -> EchoResult {
-        let box = EchoBox()
-        let ud = Unmanaged.passUnretained(box).toOpaque()
-        let cMsg = strdup(message)
-        defer { free(cMsg) }
-        var req = EchoRequest()
-        req.message = UnsafePointer(cMsg)
-        req.delayMs = Int64(delayMs)
-        guard my_timer_echo(ctx, echoCallback, ud, req) == 0 else {
-            throw TimerError.failed("echo dispatch failed")
-        }
-        box.sem.wait()
-        guard box.ret == 0 else { throw TimerError.failed(box.text) }
-        return EchoResult(echoed: box.echoed, timerName: box.timerName)
-    }
-
     deinit { my_timer_destroy(ctx) }
+
 }
 
-// MARK: - callback plumbing
-// The library calls back on its FFI thread; we keep the Box alive on the caller
-// stack (passUnretained) because the caller blocks on the semaphore until the
-// callback fires.
-
+// MARK: - shared callback plumbing
 final class Box {
     var ret: Int32 = -1
     var text = ""
     let sem = DispatchSemaphore(value: 0)
 }
-final class EchoBox {
-    var ret: Int32 = -1
-    var text = ""
-    var echoed = ""
-    var timerName = ""
-    let sem = DispatchSemaphore(value: 0)
-}
 
-private func rawText(_ msg: UnsafePointer<CChar>?, _ len: Int) -> String {
+func rawText(_ msg: UnsafePointer<CChar>?, _ len: Int) -> String {
     guard let m = msg, len > 0 else { return "" }
     let bytes = UnsafeRawPointer(m).assumingMemoryBound(to: UInt8.self)
     return String(decoding: UnsafeBufferPointer(start: bytes, count: len), as: UTF8.self)
 }
 
-private func ackCallback(_ ret: Int32, _ msg: UnsafePointer<CChar>?,
-                         _ len: Int, _ ud: UnsafeMutableRawPointer?) {
+func ackCallback(_ ret: Int32, _ msg: UnsafePointer<CChar>?,
+                 _ len: Int, _ ud: UnsafeMutableRawPointer?) {
     let box = Unmanaged<Box>.fromOpaque(ud!).takeUnretainedValue()
     box.ret = ret
     if ret != 0 { box.text = rawText(msg, len) }
     box.sem.signal()
 }
 
-private func stringCallback(_ ret: Int32, _ msg: UnsafePointer<CChar>?,
-                            _ len: Int, _ ud: UnsafeMutableRawPointer?) {
+func stringCallback(_ ret: Int32, _ msg: UnsafePointer<CChar>?,
+                    _ len: Int, _ ud: UnsafeMutableRawPointer?) {
     let box = Unmanaged<Box>.fromOpaque(ud!).takeUnretainedValue()
     box.ret = ret
     box.text = rawText(msg, len)
     box.sem.signal()
 }
 
-private func echoCallback(_ ret: Int32, _ msg: UnsafePointer<CChar>?,
+
+final class MyTimerEchoBox {
+    var ret: Int32 = -1
+    var text = ""
+    var echoed = ""
+    var timerName = ""
+    let sem = DispatchSemaphore(value: 0)
+}
+private func my_timer_echoCallback(_ ret: Int32, _ msg: UnsafePointer<CChar>?,
                           _ len: Int, _ ud: UnsafeMutableRawPointer?) {
-    let box = Unmanaged<EchoBox>.fromOpaque(ud!).takeUnretainedValue()
+    let box = Unmanaged<MyTimerEchoBox>.fromOpaque(ud!).takeUnretainedValue()
     box.ret = ret
     if ret == 0, let m = msg {
-        // Native ABI: msg is a const EchoResponse* (typed struct return).
-        let resp = UnsafeRawPointer(m).assumingMemoryBound(to: EchoResponse.self)
+        let resp = UnsafeRawPointer(m).assumingMemoryBound(to: CMyTimer.EchoResponse.self)
         box.echoed = resp.pointee.echoed.map { String(cString: $0) } ?? ""
         box.timerName = resp.pointee.timerName.map { String(cString: $0) } ?? ""
     } else {

examples/timer/ios/Tests/MyTimerTests/MyTimerTests.swift

@@ -3,7 +3,7 @@ import XCTest
 
 final class MyTimerTests: XCTestCase {
     func testCreateVersionEcho() throws {
-        let node = try TimerNode(name: "ios-demo")
+        let node = try MyTimerNode(name: "ios-demo")
 
         XCTAssertEqual(try node.version(), "nim-timer v0.1.0")
 
@@ -13,7 +13,7 @@ final class MyTimerTests: XCTestCase {
     }
 
     func testManyEchoes() throws {
-        let node = try TimerNode(name: "loop")
+        let node = try MyTimerNode(name: "loop")
         for i in 0..<200 {
             let r = try node.echo("m\(i)")
             XCTAssertEqual(r.echoed, "m\(i)")