Property predicates

Rex.xcodeproj/project.pbxproj

@@ -43,6 +43,10 @@
 		D86FFBDA1B34B3F0001A89B3 /* Action.swift in Sources */ = {isa = PBXBuildFile; fileRef = D86FFBD91B34B3F0001A89B3 /* Action.swift */; };
 		D86FFBDB1B34B3F0001A89B3 /* Action.swift in Sources */ = {isa = PBXBuildFile; fileRef = D86FFBD91B34B3F0001A89B3 /* Action.swift */; };
 		D86FFBDD1B34B691001A89B3 /* UIButton.swift in Sources */ = {isa = PBXBuildFile; fileRef = D86FFBDC1B34B691001A89B3 /* UIButton.swift */; };
+		D8A454061BD26A1A00C9E790 /* Property.swift in Sources */ = {isa = PBXBuildFile; fileRef = D8A454051BD26A1A00C9E790 /* Property.swift */; };
+		D8A454071BD26A1A00C9E790 /* Property.swift in Sources */ = {isa = PBXBuildFile; fileRef = D8A454051BD26A1A00C9E790 /* Property.swift */; };
+		D8A454091BD2772700C9E790 /* PropertyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D8A454081BD2772700C9E790 /* PropertyTests.swift */; };
+		D8A4540A1BD2772700C9E790 /* PropertyTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D8A454081BD2772700C9E790 /* PropertyTests.swift */; };
 		D8E4A6201B7BBB1600EAD8A8 /* UIBarButtonItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5173EBC71B625A6800C9B48E /* UIBarButtonItem.swift */; };
 		D8E4A6211B7BBB2100EAD8A8 /* UIBarItem.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5173EBC51B625A2600C9B48E /* UIBarItem.swift */; };
 		D8F073161B863CE70047D546 /* UILabelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D8F073141B861B3A0047D546 /* UILabelTests.swift */; };
@@ -129,6 +133,8 @@
 		D86FFBD71B34B242001A89B3 /* UILabel.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UILabel.swift; sourceTree = "<group>"; };
 		D86FFBD91B34B3F0001A89B3 /* Action.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Action.swift; sourceTree = "<group>"; };
 		D86FFBDC1B34B691001A89B3 /* UIButton.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UIButton.swift; sourceTree = "<group>"; };
+		D8A454051BD26A1A00C9E790 /* Property.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Property.swift; sourceTree = "<group>"; };
+		D8A454081BD2772700C9E790 /* PropertyTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = PropertyTests.swift; sourceTree = "<group>"; };
 		D8F073141B861B3A0047D546 /* UILabelTests.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = UILabelTests.swift; sourceTree = "<group>"; };
 		D8F0973A1B17F2F7002E15BA /* NSData.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NSData.swift; sourceTree = "<group>"; };
 		D8F0973C1B17F30D002E15BA /* NSUserDefaults.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = NSUserDefaults.swift; sourceTree = "<group>"; };
@@ -197,6 +203,7 @@
 			isa = PBXGroup;
 			children = (
 				D86FFBD91B34B3F0001A89B3 /* Action.swift */,
+				D8A454051BD26A1A00C9E790 /* Property.swift */,
 				D8003EBC1AFED01000D7D3C5 /* Signal.swift */,
 				D8003EB81AFEC7A900D7D3C5 /* SignalProducer.swift */,
 				4238D5941B4D593E008534C0 /* AppKit */,
@@ -219,6 +226,7 @@
 		D8003E9D1AFEC3D400D7D3C5 /* Tests */ = {
 			isa = PBXGroup;
 			children = (
+				D8A454081BD2772700C9E790 /* PropertyTests.swift */,
 				D8003EBE1AFED2F800D7D3C5 /* SignalTests.swift */,
 				D8003EC01AFED30100D7D3C5 /* SignalProducerTests.swift */,
 				D8F097461B17F5BF002E15BA /* Foundation */,
@@ -489,6 +497,7 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				D8A454061BD26A1A00C9E790 /* Property.swift in Sources */,
 				D86FFBDA1B34B3F0001A89B3 /* Action.swift in Sources */,
 				D86FFBD11B34AD6F001A89B3 /* Association.swift in Sources */,
 				D8003EB91AFEC7A900D7D3C5 /* SignalProducer.swift in Sources */,
@@ -507,6 +516,7 @@
 				D8F0974A1B17F5E1002E15BA /* NSObjectTests.swift in Sources */,
 				D8003EC21AFED30F00D7D3C5 /* SignalTests.swift in Sources */,
 				D8003EC31AFED30F00D7D3C5 /* SignalProducerTests.swift in Sources */,
+				D8A454091BD2772700C9E790 /* PropertyTests.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -521,6 +531,7 @@
 				D8F0973E1B17F30D002E15BA /* NSUserDefaults.swift in Sources */,
 				D834572D1AFEE45B0070616A /* Signal.swift in Sources */,
 				D8E4A6211B7BBB2100EAD8A8 /* UIBarItem.swift in Sources */,
+				D8A454071BD26A1A00C9E790 /* Property.swift in Sources */,
 				D8E4A6201B7BBB1600EAD8A8 /* UIBarButtonItem.swift in Sources */,
 				D8F097451B17F3C8002E15BA /* NSObject.swift in Sources */,
 				D834572E1AFEE45B0070616A /* SignalProducer.swift in Sources */,
@@ -540,6 +551,7 @@
 				8289A2E81BD7F7900097FB60 /* UIViewTests.swift in Sources */,
 				D8F073161B863CE70047D546 /* UILabelTests.swift in Sources */,
 				8295FD8A1B87352D007C9000 /* UIButtonTests.swift in Sources */,
+				D8A4540A1BD2772700C9E790 /* PropertyTests.swift in Sources */,
 				D83457301AFEE45E0070616A /* SignalProducerTests.swift in Sources */,
 				D83457411AFEE6050070616A /* SignalTests.swift in Sources */,
 				8295FD8D1B87374A007C9000 /* UIBarButtonItemTests.swift in Sources */,

Source/Property.swift

@@ -0,0 +1,107 @@
+//
+//  Property.swift
+//  Rex
+//
+//  Created by Neil Pankey on 10/17/15.
+//  Copyright (c) 2015 Neil Pankey. All rights reserved.
+//
+
+import ReactiveCocoa
+
+extension PropertyType where Value == Bool {
+    public func and<P: PropertyType where P.Value == Bool>(other: P) -> AndProperty {
+        return AndProperty(terms: [AnyProperty(self), AnyProperty(other)])
+    }
+
+    public func and(other: AnyProperty<Bool>) -> AndProperty {
+        return AndProperty(terms: [AnyProperty(self), other])
+    }
+
+    public func or<P: PropertyType where P.Value == Bool>(other: P) -> OrProperty {
+        return OrProperty(terms: [AnyProperty(self), AnyProperty(other)])
+    }
+
+    public func or(other: AnyProperty<Bool>) -> OrProperty {
+        return OrProperty(terms: [AnyProperty(self), other])
+    }
+
+    public func not() -> NotProperty {
+        return NotProperty(source: AnyProperty(self), invert: true)
+    }
+}
+
+public struct AndProperty: PropertyType {
+    public let terms: [AnyProperty<Bool>]
+
+    public var value: Bool {
+        return terms.reduce(true) { $0 && $1.value }
+    }
+
+    public var producer: SignalProducer<Bool, NoError> {
+        let producers = terms.map { $0.producer }
+        return combineLatest(producers).map { values in
+            return values.reduce(true) { $0 && $1 }
+        }
+    }
+
+    public func and<P : PropertyType where P.Value == Bool>(other: P) -> AndProperty {
+        return AndProperty(terms: terms + [AnyProperty(other)])
+    }
+
+    public func and(other: AnyProperty<Bool>) -> AndProperty {
+        return AndProperty(terms: terms + [other])
+    }
+
+    private init(terms: [AnyProperty<Bool>]) {
+        self.terms = terms
+    }
+}
+
+public struct OrProperty: PropertyType {
+    public let terms: [AnyProperty<Bool>]
+
+    public var value: Bool {
+        return terms.reduce(false) { $0 || $1.value }
+    }
+
+    public var producer: SignalProducer<Bool, NoError> {
+        let producers = terms.map { $0.producer }
+        return combineLatest(producers).map { values in
+            return values.reduce(false) { $0 || $1 }
+        }
+    }
+
+    public func or<P : PropertyType where P.Value == Bool>(other: P) -> OrProperty {
+        return OrProperty(terms: terms + [AnyProperty(other)])
+    }
+
+    public func or(other: AnyProperty<Bool>) -> OrProperty {
+        return OrProperty(terms: terms + [other])
+    }
+
+    private init(terms: [AnyProperty<Bool>]) {
+        self.terms = terms
+    }
+}
+
+public struct NotProperty: PropertyType {
+    private let source: AnyProperty<Bool>
+    private let invert: Bool
+
+    public var value: Bool {
+        return source.value != invert
+    }
+
+    public var producer: SignalProducer<Bool, NoError> {
+        return source.producer.map { $0 != self.invert }
+    }
+
+    public func not() -> NotProperty {
+        return NotProperty(source: source, invert: !invert)
+    }
+
+    private init(source: AnyProperty<Bool>, invert: Bool) {
+        self.source = source
+        self.invert = invert
+    }
+}

Tests/PropertyTests.swift

@@ -0,0 +1,89 @@
+//
+//  PropertyTests.swift
+//  Rex
+//
+//  Created by Neil Pankey on 10/17/15.
+//  Copyright (c) 2015 Neil Pankey. All rights reserved.
+//
+
+@testable import Rex
+import ReactiveCocoa
+import XCTest
+
+final class PropertyTests: XCTestCase {
+
+    func testAndProperty() {
+        let lhs = MutableProperty(false), rhs = MutableProperty(false)
+        let and = lhs.and(rhs)
+
+        var current: Bool!
+        and.producer.startWithNext { current = $0 }
+
+        XCTAssertFalse(and.value)
+        XCTAssertFalse(current!)
+
+        lhs.value = true
+        XCTAssertFalse(and.value)
+        XCTAssertFalse(current!)
+
+        rhs.value = true
+        XCTAssertTrue(and.value)
+        XCTAssertTrue(current!)
+
+        let (signal, pipe) = Signal<Bool, NoError>.pipe()
+        let and2 = and.and(AnyProperty(initialValue: false, signal: signal))
+        and2.producer.startWithNext { current = $0 }
+
+        XCTAssertFalse(and2.value)
+        XCTAssertFalse(current!)
+
+        pipe.sendNext(true)
+        XCTAssertTrue(and2.value)
+        XCTAssertTrue(current!)
+    }
+
+    func testOrProperty() {
+        let lhs = MutableProperty(true), rhs = MutableProperty(true)
+        let or = lhs.or(rhs)
+
+        var current: Bool!
+        or.producer.startWithNext { current = $0 }
+
+        XCTAssertTrue(or.value)
+        XCTAssertTrue(current!)
+
+        lhs.value = false
+        XCTAssertTrue(or.value)
+        XCTAssertTrue(current!)
+
+        rhs.value = false
+        XCTAssertFalse(or.value)
+        XCTAssertFalse(current!)
+
+        let (signal, pipe) = Signal<Bool, NoError>.pipe()
+        let or2 = or.or(AnyProperty(initialValue: true, signal: signal))
+        or2.producer.startWithNext { current = $0 }
+
+        XCTAssertTrue(or2.value)
+        XCTAssertTrue(current!)
+
+        pipe.sendNext(false)
+        XCTAssertFalse(or2.value)
+        XCTAssertFalse(current!)
+    }
+
+    func testNotProperty() {
+        let source = MutableProperty(false)
+        let not = source.not()
+
+        var current: Bool!
+        not.producer.startWithNext { current = $0 }
+
+        XCTAssertTrue(not.value)
+        XCTAssertTrue(current!)
+
+        source.value = true
+        XCTAssertFalse(not.value)
+        XCTAssertFalse(current!)
+    }
+}