Implement properties after factoring out protocol

ReactiveCocoa.xcodeproj/project.pbxproj

@@ -403,6 +403,8 @@
 		D08C54B71A69A3DB00AD8286 /* Event.swift in Sources */ = {isa = PBXBuildFile; fileRef = D08C54B51A69A3DB00AD8286 /* Event.swift */; };
 		D08C54B81A69A9D000AD8286 /* SignalProducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = D08C54B21A69A2AC00AD8286 /* SignalProducer.swift */; };
 		D08C54B91A69A9D100AD8286 /* SignalProducer.swift in Sources */ = {isa = PBXBuildFile; fileRef = D08C54B21A69A2AC00AD8286 /* SignalProducer.swift */; };
+		D08C54BA1A69C54300AD8286 /* Property.swift in Sources */ = {isa = PBXBuildFile; fileRef = D08C54B01A69A2AC00AD8286 /* Property.swift */; };
+		D08C54BB1A69C54400AD8286 /* Property.swift in Sources */ = {isa = PBXBuildFile; fileRef = D08C54B01A69A2AC00AD8286 /* Property.swift */; };
 		D097CE3919EF7AF5005A201C /* ColdSignal.swift in Sources */ = {isa = PBXBuildFile; fileRef = D097CE3619EF7AF5005A201C /* ColdSignal.swift */; };
 		D097CE3A19EF7AF5005A201C /* ColdSignal.swift in Sources */ = {isa = PBXBuildFile; fileRef = D097CE3619EF7AF5005A201C /* ColdSignal.swift */; };
 		D097CE3B19EF7AF5005A201C /* HotSignal.swift in Sources */ = {isa = PBXBuildFile; fileRef = D097CE3719EF7AF5005A201C /* HotSignal.swift */; };
@@ -1678,6 +1680,7 @@
 				D037656219EDA41200A782A9 /* RACCommand.m in Sources */,
 				D037658819EDA41200A782A9 /* RACErrorSignal.m in Sources */,
 				D03765F619EDA41200A782A9 /* RACSubscriptingAssignmentTrampoline.m in Sources */,
+				D08C54BA1A69C54300AD8286 /* Property.swift in Sources */,
 				D037661219EDA41200A782A9 /* RACUnit.m in Sources */,
 				D03765A019EDA41200A782A9 /* RACKVOTrampoline.m in Sources */,
 				D037650A19EDA41200A782A9 /* NSInvocation+RACTypeParsing.m in Sources */,
@@ -1813,6 +1816,7 @@
 				D037654B19EDA41200A782A9 /* NSUserDefaults+RACSupport.m in Sources */,
 				D037660F19EDA41200A782A9 /* RACUnarySequence.m in Sources */,
 				D097CE3C19EF7AF5005A201C /* HotSignal.swift in Sources */,
+				D08C54BB1A69C54400AD8286 /* Property.swift in Sources */,
 				D03765FF19EDA41200A782A9 /* RACTargetQueueScheduler.m in Sources */,
 				D03765DF19EDA41200A782A9 /* RACSignalSequence.m in Sources */,
 				D037656D19EDA41200A782A9 /* RACDelegateProxy.m in Sources */,

ReactiveCocoa/Swift/Property.swift

@@ -1,34 +1,86 @@
-/// An abstract class representing a property of type T that allows observation
-/// of its changes.
-public class Property<T> {
+/// Represents a property that allows observation of its changes.
+public protocol PropertyType {
+	typealias Value
+
 	/// The current value of the property.
-	public var value: T { get }
+	var value: Value { get }
 
 	/// A producer for Signals that will send the property's current value,
-	/// followed by all changes over time, then complete when the property has
-	/// deinitialized.
-	public let producer: SignalProducer<T>
+	/// followed by all changes over time.
+	var producer: SignalProducer<Value> { get }
+}
+
+/// Represents a read-only view to a property of type T that allows observation
+/// of its changes.
+public struct PropertyOf<T>: PropertyType {
+	public typealias Value = T
+
+	private let _value: () -> T
+	private let _producer: () -> SignalProducer<T>
+
+	public var value: T {
+		return _value()
+	}
+
+	public var producer: SignalProducer<T> {
+		return _producer()
+	}
 
-	/// Keeps this class abstract.
-	private init()
+	/// Initializes the receiver as a wrapper around the given property.
+	public init<P: PropertyType where P.Value == T>(property: P) {
+		_value = { property.value }
+		_producer = { property.producer }
+	}
 }
 
 /// A mutable property of type T that allows observation of its changes.
 ///
 /// Instances of this class are thread-safe.
-public final class MutableProperty<T>: Property<T> {
+public final class MutableProperty<T>: PropertyType {
+	public typealias Value = T
+
+	private let observer: Signal<T>.Observer
+
 	/// The current value of the property.
 	///
 	/// Setting this to a new value will notify all observers of any Signals
 	/// created from the `values` producer.
-	public override var value: T { get set }
+	public var value: T {
+		get {
+			return producer.first().value()!
+		}
+
+		set(x) {
+			sendNext(observer, x)
+		}
+	}
+
+	/// A producer for Signals that will send the property's current value,
+	/// followed by all changes over time, then complete when the property has
+	/// deinitialized.
+	public let producer: SignalProducer<T>
 
 	/// Initializes the property with the given value to start.
-	public init(_ initialValue: T)
+	public init(_ initialValue: T) {
+		let (producer, observer) = SignalProducer<T>.buffer(1)
+		self.producer = producer
+		self.observer = observer
+
+		value = initialValue
+	}
+
+	deinit {
+		sendCompleted(observer)
+	}
 }
 
-extension MutableProperty: SinkType {}
+extension MutableProperty: SinkType {
+	public func put(value: T) {
+		self.value = value
+	}
+}
 
+/*
 infix operator <~ {
 	associativity right
 	precedence 90
@@ -59,3 +111,4 @@ public func <~ <T>(property: MutableProperty<T>, producer: SignalProducer<T>)
 /// The binding will automatically terminate when either property is
 /// deinitialized.
 public func <~ <T>(destinationProperty: MutableProperty<T>, sourceProperty: Property<T>)
+*/

ReactiveCocoa/Swift/SignalProducer.swift

@@ -105,7 +105,7 @@ public struct SignalProducer<T> {
 	///
 	/// After an `Error` or `Completed` event has been added to the buffer, the
 	/// observer will not add any further events.
-	public static func buffer(capacity: Int = Int.max) -> (SignalProducer, Signal<T>.Observer) {
+	public static func buffer(_ capacity: Int = Int.max) -> (SignalProducer, Signal<T>.Observer) {
 		precondition(capacity >= 0)
 
 		let lock = NSRecursiveLock()