Merge pull request #2 from mattmassicotte/feature/asyncstream

FSEventAsyncStream

Readme.adoc

@@ -9,6 +9,14 @@ Use SPM.
 == How to Use?
 [code,swift]
 ----
+/* Using a standard callback. */
 let w = FSEventStream(path: "awesome/path", callback: { stream, event in NSLog("%@", String(describing: event)) })
 w?.startWatching()
+
+/* Or with an AsyncStream. */
+Task {
+   for await event in FSEventAsyncStream(path: "awesome/path") {
+      print(event)
+   }
+}
 ----

Sources/FSEventsWrapper/FSEventAsyncStream.swift

@@ -0,0 +1,55 @@
+import Foundation
+
+
+
+/* Needed to guard the availability of `AsyncStream.makeStream`.
+ * Once Xcode 15 is released, it should be safe to remove this. */
+#if compiler(>=5.9)
+
+/** An AsyncSequence of `FSEvent` objects. */
+@available(macOS 10.15, *)
+public struct FSEventAsyncStream : AsyncSequence {
+
+	public typealias Element = FSEvent
+
+	public struct FSEventAsyncIterator : AsyncIteratorProtocol {
+
+		private let eventStream: FSEventStream?
+		private var streamIterator: AsyncStream<FSEvent>.Iterator
+
+		init(path: String, flags: FSEventStreamCreateFlags) {
+			let (stream, continuation) = AsyncStream<FSEvent>.makeStream()
+
+			self.eventStream = FSEventStream(path: path, fsEventStreamFlags: flags, callback: { _, event in
+				continuation.yield(event)
+			})
+
+			self.streamIterator = stream.makeAsyncIterator()
+			self.eventStream?.startWatching()
+
+			if eventStream == nil {
+				continuation.finish()
+			}
+		}
+
+		public mutating func next() async -> FSEvent? {
+			await streamIterator.next()
+		}
+
+	}
+
+	public let path: String
+	public let flags: FSEventStreamCreateFlags
+
+	public init(path: String, flags: FSEventStreamCreateFlags = FSEventStreamCreateFlags(kFSEventStreamCreateFlagNone)) {
+		self.path = path
+		self.flags = flags
+	}
+
+	public func makeAsyncIterator() -> FSEventAsyncIterator {
+		FSEventAsyncIterator(path: path, flags: flags)
+	}
+
+}
+
+#endif