'Cancel' for PromiseKit option 2

Cartfile

@@ -1 +1,4 @@
-github "mxcl/PromiseKit" ~> 6.0
+#github "mxcl/PromiseKit" ~> 6.0
+github "dougzilla32/PromiseKit" "PMKCancel"
+#github "PromiseKit/Cancel" ~> 1.0
+github "dougzilla32/Cancel" ~> 1.0

Cartfile.resolved

@@ -1 +1,2 @@
-github "mxcl/PromiseKit" "6.3.3"
+github "dougzilla32/Cancel" "1.0.0"
+github "dougzilla32/PromiseKit" "a0217bd7b69af68237dcdeee0197e63259b9d445"

PMKSystemConfiguration.xcodeproj/project.pbxproj

@@ -12,6 +12,7 @@
 		6362F84F1D5D934C0021D2DD /* SCNetworkReachability+AnyPromise.m in Sources */ = {isa = PBXBuildFile; fileRef = 6362F84D1D5D934C0021D2DD /* SCNetworkReachability+AnyPromise.m */; };
 		6383E14B1D611E0D00897651 /* SCTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6383E14A1D611E0D00897651 /* SCTests.swift */; };
 		63C7FFF71D5C020D003BAE60 /* PMKSystemConfiguration.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 63C7FFA71D5BEE09003BAE60 /* PMKSystemConfiguration.framework */; };
+		911E6FC820F578E2006F49B9 /* SCNetworkReachability+Promise.swift in Sources */ = {isa = PBXBuildFile; fileRef = 911E6FC720F578E2006F49B9 /* SCNetworkReachability+Promise.swift */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXContainerItemProxy section */
@@ -34,6 +35,7 @@
 		63C7FFF21D5C020D003BAE60 /* PMKSCTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = PMKSCTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 		63CCF8121D5C0C4E00503216 /* Cartfile */ = {isa = PBXFileReference; lastKnownFileType = text; path = Cartfile; sourceTree = "<group>"; };
 		63CCF8171D5C11B500503216 /* Carthage.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = Carthage.xcconfig; sourceTree = "<group>"; };
+		911E6FC720F578E2006F49B9 /* SCNetworkReachability+Promise.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "SCNetworkReachability+Promise.swift"; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -82,6 +84,7 @@
 				6358AB791D5D4B6700B9B157 /* PMKSystemConfiguration.h */,
 				6362F84C1D5D934C0021D2DD /* SCNetworkReachability+AnyPromise.h */,
 				6362F84D1D5D934C0021D2DD /* SCNetworkReachability+AnyPromise.m */,
+				911E6FC720F578E2006F49B9 /* SCNetworkReachability+Promise.swift */,
 			);
 			path = Sources;
 			sourceTree = "<group>";
@@ -192,6 +195,7 @@
 			);
 			inputPaths = (
 				PromiseKit,
+				PMKCancel,
 			);
 			name = "Embed Carthage Frameworks";
 			outputPaths = (
@@ -208,6 +212,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				6362F84F1D5D934C0021D2DD /* SCNetworkReachability+AnyPromise.m in Sources */,
+				911E6FC820F578E2006F49B9 /* SCNetworkReachability+Promise.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

Sources/SCNetworkReachability+Promise.swift

@@ -1,5 +1,8 @@
 import SystemConfiguration
+#if !PMKCocoaPods
+import PMKCancel
 import PromiseKit
+#endif
 
 public extension SCNetworkReachability {
 
@@ -9,23 +12,31 @@ public extension SCNetworkReachability {
 
     static func promise() -> Promise<Void> {
         do {
-            var zeroAddress = sockaddr()
-            zeroAddress.sa_len = UInt8(MemoryLayout<sockaddr>.size)
-            zeroAddress.sa_family = sa_family_t(AF_INET)
-            guard let ref = SCNetworkReachabilityCreateWithAddress(nil, &zeroAddress) else {
-                throw PMKError.couldNotInitializeReachability
-            }
-
-            var flags = SCNetworkReachabilityFlags()
-            if SCNetworkReachabilityGetFlags(ref, &flags), flags.contains(.reachable) {
+            if let promise = try pending()?.promise {
+                return promise
+            } else {
                 return Promise()
             }
-
-            return try Helper(ref: ref).pending.promise
         } catch {
             return Promise(error: error)
         }
     }
+
+    fileprivate static func pending() throws -> (promise: Promise<Void>, resolver: Resolver<Void>)? {
+        var zeroAddress = sockaddr()
+        zeroAddress.sa_len = UInt8(MemoryLayout<sockaddr>.size)
+        zeroAddress.sa_family = sa_family_t(AF_INET)
+        guard let ref = SCNetworkReachabilityCreateWithAddress(nil, &zeroAddress) else {
+            throw PMKError.couldNotInitializeReachability
+        }
+
+        var flags = SCNetworkReachabilityFlags()
+        if SCNetworkReachabilityGetFlags(ref, &flags), flags.contains(.reachable) {
+            return nil
+        }
+
+        return try Helper(ref: ref).pending
+    }
 }
 
 private func callback(reachability: SCNetworkReachability, flags: SCNetworkReachabilityFlags, info: UnsafeMutableRawPointer?) {
@@ -58,3 +69,20 @@ private class Helper {
         }
     }
 }
+
+//////////////////////////////////////////////////////////// Cancellation
+
+public extension SCNetworkReachability {
+    static func promiseCC() -> CancellablePromise<Void> {
+        do {
+            if let pending = try pending() {
+                return CancellablePromise(promise: pending.promise, resolver: pending.resolver)
+            } else {
+                return CancellablePromise()
+            }
+        } catch {
+            return CancellablePromise(error: error)
+        }
+    }
+}
+

Tests/SCTests.swift

@@ -1,3 +1,4 @@
+import PMKCancel
 import PMKSystemConfiguration
 import XCTest