Change memory provider signature returning array of memory

Author: DZunke

src/Chain/Memory/EmbeddingProvider.php

@@ -25,14 +25,14 @@ public function __construct(
     ) {
     }
 
-    public function loadMemory(Input $input): ?Memory
+    public function loadMemory(Input $input): array
     {
         $messages = $input->messages->getMessages();
         /** @var MessageInterface|null $userMessage */
         $userMessage = $messages[array_key_last($messages)] ?? null;
 
         if (!$userMessage instanceof UserMessage) {
-            return null;
+            return [];
         }
 
         $userMessageTextContent = array_filter(
@@ -41,7 +41,7 @@ public function loadMemory(Input $input): ?Memory
         );
 
         if (0 === \count($userMessageTextContent)) {
-            return null;
+            return [];
         }
 
         $userMessageTextContent = array_shift($userMessageTextContent);
@@ -50,14 +50,14 @@ public function loadMemory(Input $input): ?Memory
         $vectors = $this->platform->request($this->model, $userMessageTextContent->text)->asVectors();
         $foundEmbeddingContent = $this->vectorStore->query($vectors[0]);
         if (0 === \count($foundEmbeddingContent)) {
-            return null;
+            return [];
         }
 
         $content = '## Dynamic memories fitting user message'.\PHP_EOL.\PHP_EOL;
         foreach ($foundEmbeddingContent as $document) {
             $content .= json_encode($document->metadata);
         }
 
-        return new Memory($content);
+        return [new Memory($content)];
     }
 }

src/Chain/Memory/MemoryInputProcessor.php

@@ -45,13 +45,17 @@ public function processInput(Input $input): void
 
         $memory = '';
         foreach ($this->memoryProviders as $provider) {
-            $memoryMessage = $provider->loadMemory($input);
+            $memoryMessages = $provider->loadMemory($input);
 
-            if (null === $memoryMessage) {
+            if (0 === \count($memoryMessages)) {
                 continue;
             }
 
-            $memory .= \PHP_EOL.\PHP_EOL.$memoryMessage->content;
+            $memory .= \PHP_EOL.\PHP_EOL;
+            $memory .= implode(
+                \PHP_EOL,
+                array_map(static fn (Memory $memory): string => $memory->content, $memoryMessages),
+            );
         }
 
         if ('' === $memory) {

src/Chain/Memory/MemoryProviderInterface.php

@@ -11,5 +11,8 @@
  */
 interface MemoryProviderInterface
 {
-    public function loadMemory(Input $input): ?Memory;
+    /**
+     * @return list<Memory>
+     */
+    public function loadMemory(Input $input): array;
 }

src/Chain/Memory/StaticMemoryProvider.php

@@ -21,10 +21,10 @@ public function __construct(string ...$memory)
         $this->memory = $memory;
     }
 
-    public function loadMemory(Input $input): ?Memory
+    public function loadMemory(Input $input): array
     {
         if (0 === \count($this->memory)) {
-            return null;
+            return [];
         }
 
         $content = '## Static Memory'.\PHP_EOL;
@@ -33,6 +33,6 @@ public function loadMemory(Input $input): ?Memory
             $content .= \PHP_EOL.'- '.$memory;
         }
 
-        return new Memory($content);
+        return [new Memory($content)];
     }
 }

tests/Chain/Memory/EmbeddingProviderTest.php

@@ -133,7 +133,7 @@ public function itIsNotCreatingMemoryWhenNoVectorsFound(): void
             [],
         ));
 
-        self::assertNull($memory);
+        self::assertCount(0, $memory);
     }
 
     #[Test]
@@ -171,14 +171,14 @@ public function itIsCreatingMemoryWithFoundVectors(): void
             [],
         ));
 
-        self::assertNotNull($memory);
+        self::assertCount(1, $memory);
         self::assertSame(
             <<<MARKDOWN
                 ## Dynamic memories fitting user message
 
                 {"fact":"The sky is blue"}{"fact":"Water is wet"}
                 MARKDOWN,
-            $memory->content,
+            $memory[0]->content,
         );
     }
 }

tests/Chain/Memory/MemoryInputProcessorTest.php

@@ -62,12 +62,12 @@ public function itIsAddingMemoryToSystemPrompt(): void
         $firstMemoryProvider = $this->createMock(MemoryProviderInterface::class);
         $firstMemoryProvider->expects($this->once())
             ->method('loadMemory')
-            ->willReturn(new Memory('First memory content'));
+            ->willReturn([new Memory('First memory content')]);
 
         $secondMemoryProvider = $this->createMock(MemoryProviderInterface::class);
         $secondMemoryProvider->expects($this->once())
             ->method('loadMemory')
-            ->willReturn(null);
+            ->willReturn([]);
 
         $memoryInputProcessor = new MemoryInputProcessor(
             $firstMemoryProvider,
@@ -86,7 +86,7 @@ public function itIsAddingMemoryToSystemPrompt(): void
                 You are a helpful and kind assistant.
 
                 # Conversation Memory
-                This is the memory i have found for this conversation. The memory has more weight to answer user input,
+                This is the memory I have found for this conversation. The memory has more weight to answer user input,
                 so try to answer utilizing the memory as much as possible. Your answer must be changed to fit the given
                 memory. If the memory is irrelevant, ignore it. Do not reply to the this section of the prompt and do not
                 reference it as this is just for your reference.
@@ -103,7 +103,7 @@ public function itIsAddingMemoryToSystemPromptEvenItIsEmpty(): void
         $firstMemoryProvider = $this->createMock(MemoryProviderInterface::class);
         $firstMemoryProvider->expects($this->once())
             ->method('loadMemory')
-            ->willReturn(new Memory('First memory content'));
+            ->willReturn([new Memory('First memory content')]);
 
         $memoryInputProcessor = new MemoryInputProcessor($firstMemoryProvider);
 
@@ -117,7 +117,7 @@ public function itIsAddingMemoryToSystemPromptEvenItIsEmpty(): void
         self::assertSame(
             <<<MARKDOWN
                 # Conversation Memory
-                This is the memory i have found for this conversation. The memory has more weight to answer user input,
+                This is the memory I have found for this conversation. The memory has more weight to answer user input,
                 so try to answer utilizing the memory as much as possible. Your answer must be changed to fit the given
                 memory. If the memory is irrelevant, ignore it. Do not reply to the this section of the prompt and do not
                 reference it as this is just for your reference.
@@ -128,13 +128,45 @@ public function itIsAddingMemoryToSystemPromptEvenItIsEmpty(): void
         );
     }
 
+    #[Test]
+    public function itIsAddingMultipleMemoryFromSingleProviderToSystemPrompt(): void
+    {
+        $firstMemoryProvider = $this->createMock(MemoryProviderInterface::class);
+        $firstMemoryProvider->expects($this->once())
+            ->method('loadMemory')
+            ->willReturn([new Memory('First memory content'), new Memory('Second memory content')]);
+
+        $memoryInputProcessor = new MemoryInputProcessor($firstMemoryProvider);
+
+        $memoryInputProcessor->processInput($input = new Input(
+            self::createStub(Model::class),
+            new MessageBag(),
+            []
+        ));
+
+        self::assertArrayNotHasKey('use_memory', $input->getOptions());
+        self::assertSame(
+            <<<MARKDOWN
+                # Conversation Memory
+                This is the memory I have found for this conversation. The memory has more weight to answer user input,
+                so try to answer utilizing the memory as much as possible. Your answer must be changed to fit the given
+                memory. If the memory is irrelevant, ignore it. Do not reply to the this section of the prompt and do not
+                reference it as this is just for your reference.
+
+                First memory content
+                Second memory content
+                MARKDOWN,
+            $input->messages->getSystemMessage()->content,
+        );
+    }
+
     #[Test]
     public function itIsNotAddingAnythingIfMemoryWasEmpty(): void
     {
         $firstMemoryProvider = $this->createMock(MemoryProviderInterface::class);
         $firstMemoryProvider->expects($this->once())
             ->method('loadMemory')
-            ->willReturn(null);
+            ->willReturn([]);
 
         $memoryInputProcessor = new MemoryInputProcessor($firstMemoryProvider);
 

tests/Chain/Memory/StaticMemoryProviderTest.php

@@ -34,7 +34,7 @@ public function itsReturnsNullWhenNoFactsAreProvided(): void
             []
         ));
 
-        self::assertNull($memory);
+        self::assertCount(0, $memory);
     }
 
     #[Test]
@@ -51,8 +51,9 @@ public function itDeliversFormattedFacts(): void
             []
         ));
 
-        self::assertInstanceOf(Memory::class, $memory);
+        self::assertCount(1, $memory);
+        self::assertInstanceOf(Memory::class, $memory[0]);
         $expectedContent = "## Static Memory\n\n- {$fact1}\n- {$fact2}";
-        self::assertSame($expectedContent, $memory->content);
+        self::assertSame($expectedContent, $memory[0]->content);
     }
 }