feat: add AppendableValue for managing AgentState property array

.swiftpm/xcode/xcshareddata/xcschemes/LangGraph.xcscheme

@@ -0,0 +1,79 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1530"
+   version = "1.7">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES"
+      buildArchitectures = "Automatic">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "LangGraph"
+               BuildableName = "LangGraph"
+               BlueprintName = "LangGraph"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      shouldAutocreateTestPlan = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "LangGraphTests"
+               BuildableName = "LangGraphTests"
+               BlueprintName = "LangGraphTests"
+               ReferencedContainer = "container:">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "LangGraph"
+            BuildableName = "LangGraph"
+            BlueprintName = "LangGraph"
+            ReferencedContainer = "container:">
+         </BuildableReference>
+      </MacroExpansion>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

Sources/LangGraph/LangGraph.swift

@@ -5,15 +5,44 @@ public typealias PartialAgentState = [String: Any]
 public typealias NodeAction<Action: AgentState> = ( Action ) async throws -> PartialAgentState
 public typealias EdgeCondition<Action: AgentState> = ( Action ) async throws -> String
 
+public struct AppendableValue {
+    var array: [Any]
+
+    mutating func append( values: [Any] ) {
+        array.append(contentsOf: values)
+    }
+    mutating func append( value: Any ) {
+        array.append(value)
+    }
+
+    public init() {
+        array = []
+    }
+
+    public init( values: [Any] ) {
+        array = values
+    }
+}
+
 public protocol AgentState {
 
-    var data: [String: Any] { get }
+    var data: [String: Any] { get set }
 
 //    subscript(key: String) -> Any? { get }
 
-    init()
     init( _ initState: [String: Any] )
+    init()
+}
+
+extension AgentState {
 
+    public func value<T>( _ key: String ) -> T? {
+        return data[ key ] as? T
+    }
+
+    public func appendableValue<T>( _ key: String ) -> [T]? {
+        return (data[ key ] as? AppendableValue)?.array as? [T]
+    }
 }
 
 public struct BaseAgentState : AgentState {
@@ -139,8 +168,19 @@ public class GraphState<State: AgentState>  {
             if partialState.isEmpty {
                 return currentState
             }
-            let newState = currentState.data.merging(partialState, uniquingKeysWith: { (current, _) in
-                return current
+            let newState = currentState.data.merging(partialState, uniquingKeysWith: { 
+                (current, new) in
+
+                if var appender = current as? AppendableValue {
+                    if let newValue = new as? [Any] {
+                        appender.append(values: newValue)
+                    }
+                    else {
+                        appender.append(value: new)
+                    }
+                    return appender
+                }
+                return new
             })
             return State.init(newState)
         }
@@ -167,7 +207,7 @@ public class GraphState<State: AgentState>  {
 
         public func invoke( inputs: PartialAgentState, verbose:Bool = false ) async throws -> State {
 
-            var currentState = self.stateType.init( inputs )
+            var currentState = mergeState( currentState: self.stateType.init(), partialState: inputs)
             var currentNodeId = entryPoint
 
             repeat {

Tests/LangGraphTests/LangGraphTests.swift

@@ -10,16 +10,39 @@ import XCTest
 final class LangGraphTests: XCTestCase {
 
 
+    func compareAsEquatable(_ value: Any, _ expectedValue: Any) -> Bool {
+        if let value1 = value as? Int, let value2 = expectedValue as? Int {
+            return value1 == value2
+        }
+        if let value1 = value as? String, let value2 = expectedValue as? String {
+            return value1 == value2
+        }
+        if let values2 = expectedValue as? [Any] {
+            if let values1 = value as? [Any] {
+                if values1.count == values2.count {
+                    for ( v1, v2) in zip(values1, values2) {
+                        return compareAsEquatable( v1, v2 )
+                    }
+                }
+            }
+            if let value1 = value as? AppendableValue {
+                if value1.array.count == values2.count {
+                    for ( v1, v2) in zip(value1.array, values2) {
+                        return compareAsEquatable( v1, v2 )
+                    }
+                }
+
+            }
+        }
+        return false
+    }
+
     func assertDictionaryOfAnyEqual( _ expected: [String:Any], _ current: [String:Any] ) {
         XCTAssertEqual(current.count, expected.count, "the dictionaries have different size")
         for (key, value) in current {
 
-            if let value1 = value as? Int, let value2 = expected[key] as? Int {
-                XCTAssertTrue( value1 == value2 )
-            }
-            if let value1 = value as? String, let value2 = expected[key] as? String {
-                XCTAssertTrue( value1 == value2 )
-            }
+            XCTAssertTrue( compareAsEquatable(value, expected[key]!) )
+
         }
 
     }
@@ -253,6 +276,54 @@ final class LangGraphTests: XCTestCase {
         assertDictionaryOfAnyEqual(["op": "sum", "add1": 37, "add2": 10, "result": 47 ], resultAdd.data)
     }
 
-
+    struct AgentStateWithAppender : AgentState {
+        var data: [String : Any]
+
+        init() {
+            self.init( ["messages": AppendableValue()] )
+        }
+
+        init(_ initState: [String : Any]) {
+            data = initState
+        }
+        var messages:[String]? {
+           appendableValue("messages")
+        }
+    }
+
+    func testAppender() async throws {
+
+        let workflow = GraphState( stateType: AgentStateWithAppender.self )
+
+        try workflow.addNode("agent_1") { state in
+
+            print( "agent_1", state )
+            return ["messages": "message1"]
+        }
+        try workflow.addNode("agent_2") { state in
+
+            print( "agent_2", state )
+            return ["messages": ["message2", "message3"] ]
+        }
+        try workflow.addNode("agent_3") { state in
+            print( "agent_3", state )
+            return ["result": state.messages?.count ?? 0]
+        }
+
+        try workflow.addEdge(sourceId: "agent_1", targetId: "agent_2")
+        try workflow.addEdge(sourceId: "agent_2", targetId: "agent_3")
+
+        try workflow.setEntryPoint("agent_1")
+        workflow.setFinishPoint("agent_3")
+
+        let app = try workflow.compile()
+
+        let result = try await app.invoke(inputs: [ : ] )
+
+        print( result.data )
+        assertDictionaryOfAnyEqual( ["messages": [ "message1", "message2", "message3"], "result":  3 ], result.data )
+
+    }
+
 
 }