Add ReActFunctionCallingChatAgent

Tool/Sources/LangChain/Agent.swift

@@ -64,16 +64,19 @@ public struct AgentFinish<Output: AgentOutputParsable> {
 public enum AgentNextStep<Output: AgentOutputParsable> {
     case actions([AgentAction])
     case finish(AgentFinish<Output>)
-    case thought(String)
 }
 
 public struct AgentScratchPad<Content: Equatable>: Equatable {
-    var content: Content
+    public var content: Content
+
+    public init(content: Content) {
+        self.content = content
+    }
 }
 
 public struct AgentInput<T, ScratchPadContent: Equatable> {
-    var input: T
-    var thoughts: AgentScratchPad<ScratchPadContent>
+    public var input: T
+    public var thoughts: AgentScratchPad<ScratchPadContent>
 
     public init(input: T, thoughts: AgentScratchPad<ScratchPadContent>) {
         self.input = input
@@ -146,8 +149,6 @@ public extension Agent {
                 return finish
             case .actions:
                 return .init(returnValue: .unstructured(output.content ?? ""), log: output.content ?? "")
-            case let .thought(content):
-                return .init(returnValue: .unstructured(content), log: content)
             }
         }
     }

Tool/Sources/LangChain/AgentExecutor.swift

@@ -18,19 +18,22 @@ public actor AgentExecutor<InnerAgent: Agent>: Chain
     var earlyStopHandleType: AgentEarlyStopHandleType
     var now: () -> Date = { Date() }
     var isCancelled = false
+    var initialSteps: [AgentAction]
 
     public init(
         agent: InnerAgent,
         tools: [AgentTool],
         maxIteration: Int? = 10,
         maxExecutionTime: Double? = nil,
-        earlyStopHandleType: AgentEarlyStopHandleType = .force
+        earlyStopHandleType: AgentEarlyStopHandleType = .force,
+        initialSteps: [AgentAction] = []
     ) {
         self.agent = agent
         self.tools = tools.reduce(into: [:]) { $0[$1.name] = $1 }
         self.maxIteration = maxIteration
         self.maxExecutionTime = maxExecutionTime
         self.earlyStopHandleType = earlyStopHandleType
+        self.initialSteps = initialSteps
     }
 
     public func callLogic(
@@ -41,7 +44,7 @@ public actor AgentExecutor<InnerAgent: Agent>: Chain
 
         let startTime = now().timeIntervalSince1970
         var iterations = 0
-        var intermediateSteps: [AgentAction] = []
+        var intermediateSteps: [AgentAction] = initialSteps
 
         func shouldContinue() -> Bool {
             if isCancelled { return false }
@@ -84,8 +87,6 @@ public actor AgentExecutor<InnerAgent: Agent>: Chain
                         callbackManagers: callbackManagers
                     )
                 }
-            case .thought:
-                break
             }
             iterations += 1
         }
@@ -152,6 +153,10 @@ extension AgentExecutor {
                 for action in actions {
                     callbackManagers
                         .forEach { $0.send(CallbackEvents.AgentActionDidStart(info: action)) }
+                    if action.observation != nil {
+                        taskGroup.addTask { action }
+                        continue
+                    }
                     guard let tool = tools[action.toolName] else { throw InvalidToolError() }
                     taskGroup.addTask {
                         let observation = try await tool.run(input: action.toolInput)
@@ -169,15 +174,6 @@ extension AgentExecutor {
             }
 
             return .actions(completedActions)
-        case let .thought(content):
-            return .actions([
-                .init(
-                    toolName: "Thought",
-                    toolInput: content,
-                    log: "Thought: \(content)",
-                    observation: nil
-                ),
-            ])
         }
     }
 

Tool/Sources/LangChain/Agents/FunctionCallingChatAgent.swift

@@ -213,8 +213,6 @@ public class FunctionCallingChatAgent<Output: AgentOutputParsable & Decodable>:
             case let .unstructured(x), let .structured(x):
                 return .finish(.init(returnValue: .unstructured(x), log: finish.log))
             }
-        case let .thought(content):
-            return .finish(.init(returnValue: .unstructured(content), log: content))
         }
     }
 }

Tool/Sources/LangChain/Chains/LLMChain.swift

@@ -3,9 +3,9 @@ import Foundation
 public class ChatModelChain<Input>: Chain {
     public typealias Output = ChatMessage
 
-    var chatModel: ChatModel
-    var promptTemplate: (Input) -> [ChatMessage]
-    var stops: [String]
+    public internal(set) var chatModel: ChatModel
+    public internal(set) var promptTemplate: (Input) -> [ChatMessage]
+    public internal(set) var stops: [String]
 
     public init(
         chatModel: ChatModel,

Tool/Sources/Logger/Logger.swift

@@ -10,6 +10,7 @@ enum LogLevel: String {
 public final class Logger {
     private let subsystem: String
     private let category: String
+    private let osLog: OSLog
 
     public static let service = Logger(category: "Service")
     public static let ui = Logger(category: "UI")
@@ -25,6 +26,7 @@ public final class Logger {
     public init(subsystem: String = "com.intii.CopilotForXcode", category: String) {
         self.subsystem = subsystem
         self.category = category
+        osLog = OSLog(subsystem: subsystem, category: category)
     }
 
     func log(level: LogLevel, message: String) {
@@ -38,7 +40,6 @@ public final class Logger {
             osLogType = .error
         }
 
-        let osLog = OSLog(subsystem: subsystem, category: category)
         os_log("%{public}@", log: osLog, type: osLogType, message as CVarArg)
     }
 
@@ -57,4 +58,8 @@ public final class Logger {
     public func error(_ error: Error) {
         log(level: .error, message: error.localizedDescription)
     }
+
+    public func signpost(_ type: OSSignpostType, name: StaticString) {
+        os_signpost(type, log: osLog, name: name)
+    }
 }