-some cleanup in the rules engine

LICENSE

@@ -186,7 +186,7 @@
       same "printed page" as the copyright notice for easier
       identification within third-party archives.
 
-   Copyright 2020 Adobe
+   Copyright 2021 Adobe
 
    Licensed under the Apache License, Version 2.0 (the "License");
    you may not use this file except in compliance with the License.

README.md

@@ -8,11 +8,43 @@ AEPRulesEngine is currently in beta. Use of this code is by invitation only and
 
 A simple, generic, extensible Rules Engine in Swift.
 
+## Requirements
+- Xcode 11.0 (or newer)
+- Swift 5.0 (or newer)
+
 ## Installation
 
+### [CocoaPods](https://guides.cocoapods.org/using/using-cocoapods.html)
+```ruby
+# Podfile
+use_frameworks!
+
+# for app development, include all the following pods
+target 'YOUR_TARGET_NAME' do
+    pod 'AEPRulesEngine', :git => 'https://github.com/adobe/aepsdk-rulesengine-ios.git', :branch => 'main'
+    pod 'AEPCore', :git => 'https://github.com/adobe/aepsdk-core-ios.git', :branch => 'main'
+    pod 'AEPServices', :git => 'https://github.com/adobe/aepsdk-core-ios.git', :branch => 'main'
+    pod 'AEPLifecycle', :git => 'https://github.com/adobe/aepsdk-core-ios.git', :branch => 'main'
+    pod 'AEPIdentity', :git => 'https://github.com/adobe/aepsdk-core-ios.git', :branch => 'main'    
+end
+
+# for extension development, include AEPCore and its dependencies
+target 'YOUR_TARGET_NAME' do
+    pod 'AEPRulesEngine', :git => 'https://github.com/adobe/aepsdk-rulesengine-ios.git', :branch => 'main'
+    pod 'AEPCore', :git => 'https://github.com/adobe/aepsdk-core-ios.git', :branch => 'main'
+    pod 'AEPServices', :git => 'https://github.com/adobe/aepsdk-core-ios.git', :branch => 'main'    
+end
+```
+
+Replace `YOUR_TARGET_NAME` and then, in the `Podfile` directory, type:
+
+```bash
+$ pod install
+```
+
 ### Swift Package Manager
 
-To add the AEPRulesEngine Package to your application, from the Xcode menu select:
+To add the AEPRulesEngine package to your application, from the Xcode menu select:
 
 `File > Swift Packages > Add Package Dependency...`
 
@@ -37,17 +69,17 @@ dependencies: [
 ## Usage
 
 
-### Initialize Rules Engine
+### Initialize the Rules Engine
 
-To create a `RuleEngine` instance, first define an `Evaluator` and then use it as the parameter for `RuleEngine`.
+To create a `RulesEngine` instance, define an `Evaluator` and pass it to the `RulesEngine`'s initializer:
 ```
 let evaluator = ConditionEvaluator(options: .caseInsensitive)
 let rulesEngine = RulesEngine(evaluator: evaluator)
 ```
 
 ### Define Rules
 
-Any thing that conforms to the `Rule` protocol can be used as rule. 
+Anything that conforms to the `Rule` protocol can be used as rule:
 ``` Swift
 public class MobileRule: Rule {
     init(condition: Evaluable) { self.condition = condition }
@@ -57,7 +89,7 @@ let condition = ComparisonExpression(lhs: "abc", operationName: "equals", rhs: "
 let rule = MobileRule(condition: condition)
 rulesEngine.addRules(rules: [rule])
 ```
-However, a rule like this doesn't make much sense, without the ability to dynamically fetch a value it will always be true or false.
+A rule without the flexibility to dynamically fetch a value will always evaluate to true or false.  To fetch the value for a rule at runtime, use a Mustache Token:
 
 ``` Swift
 let mustache = Operand<String>(mustache: "{{company}}")
@@ -68,7 +100,7 @@ rulesEngine.addRules(rules: [rule])
 
 ### Evaluate data
 
-Use the method `evaluate` to run rule engine on the input data that is `Traversable`.
+Use the `evaluate` method to process `Traversable` data through the `RulesEngine`:
 
 ```
 let matchedRules = rulesEngine.evaluate(data: ["company":"adobe"])

Sources/AEPRulesEngine/ConditionEvaluator.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
@@ -13,11 +13,14 @@
 public class ConditionEvaluator: Evaluating {
     fileprivate let LOG_TAG = "ConditionEvaluator"
     var operators: [String: Any] = [:]
+
+    // MARK: - Evaluating
     public func evaluate<A>(operation: String, lhs: A) -> Result<Bool, RulesFailure> {
         let op = operators[getHash(operation: operation, typeA: A.self)] as? ((A) -> Bool)
+
         guard let op_ = op else {
-            let message = "Operator not defined for \(getHash(operation: operation, typeA: A.self))"
-            RulesEngineLog.trace(label: LOG_TAG, message)
+            let message = "No operator defined for \(getHash(operation: operation, typeA: A.self))"
+            Log.trace(label: LOG_TAG, message)
             return Result.failure(RulesFailure.missingOperator(message: message))
         }
         return op_(lhs) ? Result.success(true) : Result.failure(.conditionNotMatched(message: "(\(String(describing: A.self))(\(lhs)) \(operation))"))
@@ -27,8 +30,8 @@ public class ConditionEvaluator: Evaluating {
         let op = operators[getHash(operation: operation, typeA: A.self, typeB: B.self)] as? ((A, B) -> Bool)
 
         guard let op_ = op else {
-            let message = "Operator not defined for \(getHash(operation: operation, typeA: A.self, typeB: B.self))"
-            RulesEngineLog.trace(label: LOG_TAG, message)
+            let message = "No operator defined for \(getHash(operation: operation, typeA: A.self, typeB: B.self))"
+            Log.trace(label: LOG_TAG, message)
             return Result.failure(RulesFailure.missingOperator(message: message))
         }
         return op_(lhs, rhs) ? Result.success(true) : Result.failure(.conditionNotMatched(message: "\(String(describing: A.self))(\(lhs)) \(operation) \(String(describing: B.self))(\(rhs))"))
@@ -78,6 +81,7 @@ public extension ConditionEvaluator {
     }
 
     private func addDefaultOperators() {
+
         addComparisonOperator(operation: "and", type: Bool.self, closure: { $0 && $1 })
         addComparisonOperator(operation: "or", type: Bool.self, closure: { $0 || $1 })
 
@@ -117,9 +121,11 @@ public extension ConditionEvaluator {
     }
 
     private func addCaseInSensitiveOperators() {
-        addComparisonOperator(operation: "startsWith", type: String.self, closure: { $0.lowercased().starts(with: $1.lowercased()) })
         addComparisonOperator(operation: "equals", type: String.self, closure: { $0.lowercased() == $1.lowercased() })
+        addComparisonOperator(operation: "notEquals", type: String.self, closure: { $0.lowercased() != $1.lowercased() })
+        addComparisonOperator(operation: "startsWith", type: String.self, closure: { $0.lowercased().starts(with: $1.lowercased()) })
         addComparisonOperator(operation: "endsWith", type: String.self, closure: { $0.lowercased().hasSuffix($1.lowercased()) })
         addComparisonOperator(operation: "contains", type: String.self, closure: { $0.lowercased().contains($1.lowercased()) })
+        addComparisonOperator(operation: "notContains", type: String.self, closure: { !$0.lowercased().contains($1.lowercased()) })
     }
 }

Sources/AEPRulesEngine/Context.swift

@@ -0,0 +1,20 @@
+/*
+ Copyright 2021 Adobe. All rights reserved.
+ This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License. You may obtain a copy
+ of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software distributed under
+ the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ OF ANY KIND, either express or implied. See the License for the specific language
+ governing permissions and limitations under the License.
+ */
+
+import Foundation
+
+/// A type that contains all pieces necessary for boolean evaluation
+public struct Context {
+    public let data: Traversable
+    public let evaluator: Evaluating
+    public let transformer: Transforming
+}

Sources/AEPRulesEngine/Evaluating.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0

Sources/AEPRulesEngine/Expression/ComparisonExpression.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
@@ -24,8 +24,10 @@ public struct ComparisonExpression<A, B>: Evaluable {
         self.operationName = operationName
     }
 
+    // MARK: - Evaluable
+
     public func evaluate(in context: Context) -> Result<Bool, RulesFailure> {
-        RulesEngineLog.trace(label: LOG_TAG, "Evaluating \(lhs) - \(operationName) - \(rhs)")
+        Log.trace(label: LOG_TAG, "Evaluating \(lhs) - \(operationName) - \(rhs)")
         let resolvedLhs = lhs(context)
         let resolvedRhs = rhs(context)
         var result: Result<Bool, RulesFailure>
@@ -38,8 +40,8 @@ public struct ComparisonExpression<A, B>: Evaluable {
         case .success:
             return result
         case let .failure(error):
-            RulesEngineLog.debug(label: LOG_TAG, "Failed to evaluate \(String(describing: resolvedLhs)) - \(operationName) - \(String(describing: resolvedRhs))")
-            return Result.failure(.innerFailure(message: "Comparison (\(lhs) \(operationName) \(rhs)) returns false", error: error))
+            Log.debug(label: LOG_TAG, "Failed to evaluate \(String(describing: resolvedLhs)) - \(operationName) - \(String(describing: resolvedRhs))")
+            return Result.failure(.innerFailure(message: "Comparison (\(lhs) \(operationName) \(rhs)) returned false", error: error))
         }
     }
 }

Sources/AEPRulesEngine/Evaluable.swift → Sources/AEPRulesEngine/Expression/Evaluable.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0

Sources/AEPRulesEngine/Expression/LogicalExpression.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
@@ -43,7 +43,7 @@ public struct LogicalExpression: Evaluable {
             }
             return Result.failure(.innerFailures(message: "`Or` returns false", errors: operandsResolve.filter { !$0.value }.map { $0.error ?? RulesFailure.unknown }))
         default:
-            return .failure(.missingOperator(message: "Unkonwn conjunction operator"))
+            return .failure(.missingOperator(message: "Unknown conjunction operator '\(operationName)'"))
         }
     }
 }

Sources/AEPRulesEngine/Expression/Operand.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
@@ -51,9 +51,9 @@ extension Operand: CustomStringConvertible {
         case .none:
             return "<None>"
         case let .some(value):
-            return "<Value:\(value)>"
+            return "<Value: \(value)>"
         case let .token(mustache):
-            return "<Token:\(mustache)>"
+            return "<Token: \(mustache)>"
         }
     }
 }

Sources/AEPRulesEngine/Expression/UnaryExpression.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
@@ -23,7 +23,7 @@ public struct UnaryExpression<A>: Evaluable {
     }
 
     public func evaluate(in context: Context) -> Result<Bool, RulesFailure> {
-        RulesEngineLog.trace(label: LOG_TAG, "Evaluating \(operationName) - \(lhs)")
+        Log.trace(label: LOG_TAG, "Evaluating \(operationName) - \(lhs)")
         let resolvedLhs = lhs(context)
         if let resolvedLhs_ = resolvedLhs {
             return context.evaluator.evaluate(operation: operationName, lhs: resolvedLhs_)

Sources/AEPRulesEngine/RulesEngineLog.swift → Sources/AEPRulesEngine/Log/Log.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
@@ -12,8 +12,11 @@
 
 import Foundation
 
-public class RulesEngineLog {
-    public static var logging: RulesEngineLogging?
+/// The `Log` class will be dormant unless its static `logging` variable is initialized.
+/// To enable logging from the RulesEngine, implement a class that conforms to the
+/// `Logging` protocol and use an instance of it to set the `Log.logging` variable.
+public class Log {
+    public static var logging: Logging?
     /// Used to print more verbose information.
     /// - Parameters:
     ///   - label: the name of the label to localize message

Sources/AEPRulesEngine/RulesEngineLogging.swift → Sources/AEPRulesEngine/Log/LogLevel.swift

@@ -1,40 +1,32 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0
-
+ 
  Unless required by applicable law or agreed to in writing, software distributed under
  the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
  OF ANY KIND, either express or implied. See the License for the specific language
  governing permissions and limitations under the License.
  */
 
 import Foundation
-public protocol RulesEngineLogging {
-    /// Logs a message
-    /// - Parameters:
-    ///   - level: One of the message level identifiers, e.g., DEBUG
-    ///   - label: Name of a label to localize message
-    ///   - message: The string message
-    func log(level: RulesEngineLogLevel, label: String, message: String)
-}
 
-public enum RulesEngineLogLevel: Int, Comparable {
+public enum LogLevel: Int, Comparable {
     case error = 0
     case warning = 1
     case debug = 2
     case trace = 3
-
-    /// Compares two `RulesEngineLogLevel`s for order
+    
+    /// Compares two `LogLevel`s for order
     /// - Parameters:
-    ///   - lhs: the first `RulesEngineLogLevel` to be compared
-    ///   - rhs: the second `RulesEngineLogLevel` to be compared
-    /// - Returns: true, only if the second `LogLevel` is more critical
-    public static func < (lhs: RulesEngineLogLevel, rhs: RulesEngineLogLevel) -> Bool {
+    ///   - lhs: the first `LogLevel` to be compared
+    ///   - rhs: the second `LogLevel` to be compared
+    /// - Returns: true if the second `LogLevel` is more critical
+    public static func < (lhs: LogLevel, rhs: LogLevel) -> Bool {
         lhs.rawValue < rhs.rawValue
     }
-
+    
     public func toString() -> String {
         switch self {
         case .trace:

Sources/AEPRulesEngine/Log/Logging.swift

@@ -0,0 +1,22 @@
+/*
+ Copyright 2021 Adobe. All rights reserved.
+ This file is licensed to you under the Apache License, Version 2.0 (the "License");
+ you may not use this file except in compliance with the License. You may obtain a copy
+ of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+ Unless required by applicable law or agreed to in writing, software distributed under
+ the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR REPRESENTATIONS
+ OF ANY KIND, either express or implied. See the License for the specific language
+ governing permissions and limitations under the License.
+ */
+
+import Foundation
+
+public protocol Logging {
+    /// Logs a message
+    /// - Parameters:
+    ///   - level: A `LogLevel` identifying the severity of the log. e.g. - `.debug`
+    ///   - label: Label for the log
+    ///   - message: The `String` message
+    func log(level: LogLevel, label: String, message: String)
+}

Sources/AEPRulesEngine/Operand+Literal.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0

Sources/AEPRulesEngine/Result+RulesFailure.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0

Sources/AEPRulesEngine/Rule.swift

@@ -1,5 +1,5 @@
 /*
- Copyright 2020 Adobe. All rights reserved.
+ Copyright 2021 Adobe. All rights reserved.
  This file is licensed to you under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License. You may obtain a copy
  of the License at http://www.apache.org/licenses/LICENSE-2.0