Adding initial Chain feature

* Add Chain interface
* Add OuputParser interface
* Add Memory interface
* Rework core prompt OO models
* Change to use PromptTemplateActions as the interface for PromptTemplate

spring-ai-azure-openai/src/main/java/org/springframework/ai/azure/openai/llm/AzureOpenAiClient.java

@@ -22,7 +22,7 @@
 import org.slf4j.LoggerFactory;
 import org.springframework.ai.core.llm.LLMResult;
 import org.springframework.ai.core.llm.LlmClient;
-import org.springframework.ai.core.prompt.Generation;
+import org.springframework.ai.core.llm.Generation;
 import org.springframework.ai.core.prompt.Prompt;
 import org.springframework.ai.core.prompt.messages.Message;
 import org.springframework.util.Assert;

spring-ai-core/src/main/java/org/springframework/ai/core/chain/AbstractChain.java

@@ -0,0 +1,67 @@
+package org.springframework.ai.core.chain;
+
+import org.springframework.ai.core.memory.Memory;
+
+import java.util.*;
+
+public abstract class AbstractChain implements Chain {
+
+	private Optional<Memory> memory = Optional.empty();
+
+	public Optional<Memory> getMemory() {
+		return this.memory;
+	}
+
+	public void setMemory(Memory memory) {
+		Objects.requireNonNull(memory, "Memory can not be null.");
+		this.memory = Optional.of(memory);
+	}
+
+	@Override
+	public abstract List<String> getInputKeys();
+
+	@Override
+	public abstract List<String> getOutputKeys();
+
+	// TODO validation of input/outputs
+
+	@Override
+	public Map<String, Object> apply(Map<String, Object> inputMap) {
+		Map<String, Object> inputMapToUse = processBeforeApply(inputMap);
+		Map<String, Object> outputMap = doApply(inputMapToUse);
+		Map<String, Object> outputMapToUse = processAfterApply(inputMapToUse, outputMap);
+		return outputMapToUse;
+	}
+
+	protected Map<String, Object> processBeforeApply(Map<String, Object> inputMap) {
+		validateInputs(inputMap);
+		return inputMap;
+	}
+
+	protected abstract Map<String, Object> doApply(Map<String, Object> inputMap);
+
+	private Map<String, Object> processAfterApply(Map<String, Object> inputMap, Map<String, Object> outputMap) {
+		validateOutputs(outputMap);
+		Map<String, Object> combindedMap = new HashMap<>();
+		combindedMap.putAll(inputMap);
+		combindedMap.putAll(outputMap);
+		return combindedMap;
+	}
+
+	protected void validateOutputs(Map<String, Object> outputMap) {
+		Set<String> missingKeys = new HashSet<>(getOutputKeys());
+		missingKeys.removeAll(outputMap.keySet());
+		if (!missingKeys.isEmpty()) {
+			throw new IllegalArgumentException("Missing some output keys: " + missingKeys);
+		}
+	}
+
+	protected void validateInputs(Map<String, Object> inputMap) {
+		Set<String> missingKeys = new HashSet<>(getInputKeys());
+		missingKeys.removeAll(inputMap.keySet());
+		if (!missingKeys.isEmpty()) {
+			throw new IllegalArgumentException("Missing some input keys: " + missingKeys);
+		}
+	}
+
+}

spring-ai-core/src/main/java/org/springframework/ai/core/chain/Chain.java

@@ -0,0 +1,13 @@
+package org.springframework.ai.core.chain;
+
+import java.util.List;
+import java.util.Map;
+import java.util.function.Function;
+
+public interface Chain extends Function<Map<String, Object>, Map<String, Object>> {
+
+	List<String> getInputKeys();
+
+	List<String> getOutputKeys();
+
+}

spring-ai-core/src/main/java/org/springframework/ai/core/prompt/Generation.java → spring-ai-core/src/main/java/org/springframework/ai/core/llm/Generation.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.ai.core.prompt;
+package org.springframework.ai.core.llm;
 
 import java.util.HashMap;
 import java.util.Map;

spring-ai-core/src/main/java/org/springframework/ai/core/llm/LLMResult.java

@@ -15,8 +15,6 @@
  */
 package org.springframework.ai.core.llm;
 
-import org.springframework.ai.core.prompt.Generation;
-
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;

spring-ai-core/src/main/java/org/springframework/ai/core/memory/Memory.java

@@ -0,0 +1,22 @@
+package org.springframework.ai.core.memory;
+
+import java.util.List;
+import java.util.Map;
+
+public interface Memory {
+
+	/**
+	 * The keys that the memory will add to Chain inputs
+	 */
+	List<String> getKeys();
+
+	/**
+	 * Return key-value pairs given the text input to the chain
+	 * @param inputs input of the chain
+	 * @return key-value pairs from memory
+	 */
+	Map<String, Object> load(Map<String, Object> inputs);
+
+	void save(Map<String, Object> inputs, Map<String, Object> outputs);
+
+}

spring-ai-core/src/main/java/org/springframework/ai/core/parser/OutputParser.java

@@ -0,0 +1,11 @@
+package org.springframework.ai.core.parser;
+
+import org.springframework.ai.core.llm.Generation;
+
+import java.util.List;
+
+public interface OutputParser<T> {
+
+	T parse(List<Generation> output);
+
+}

spring-ai-core/src/main/java/org/springframework/ai/core/prompt/ChatPromptTemplate.java

@@ -16,32 +16,70 @@
 
 package org.springframework.ai.core.prompt;
 
-import org.springframework.ai.core.prompt.messages.ChatMessage;
-import org.springframework.ai.core.prompt.messages.MessageType;
+import org.springframework.ai.core.prompt.messages.Message;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Map;
 
 /**
  * A PromptTemplate that lets you specify the role as a string should the current
  * implementations and their roles not suffice for your needs.
  */
-public class ChatPromptTemplate extends PromptTemplate {
+public class ChatPromptTemplate implements PromptTemplateActions {
 
-	private MessageType messageType;
+	private final List<PromptTemplate> promptTemplates;
 
-	public ChatPromptTemplate(MessageType messageType, String template) {
-		super(template);
-		this.messageType = messageType;
+	public ChatPromptTemplate(List<PromptTemplate> promptTemplates) {
+		this.promptTemplates = promptTemplates;
+	}
+
+	@Override
+	public String render() {
+		StringBuilder sb = new StringBuilder();
+		for (PromptTemplate promptTemplate : promptTemplates) {
+			sb.append(promptTemplate.render());
+		}
+		return sb.toString();
+	}
+
+	@Override
+	public String render(Map<String, Object> model) {
+		StringBuilder sb = new StringBuilder();
+		for (PromptTemplate promptTemplate : promptTemplates) {
+			sb.append(promptTemplate.render(model));
+		}
+		return sb.toString();
+	}
+
+	@Override
+	public List<Message> createMessages() {
+		List<Message> messages = new ArrayList<>();
+		for (PromptTemplate promptTemplate : promptTemplates) {
+			messages.addAll(promptTemplate.createMessages());
+		}
+		return messages;
+	}
+
+	@Override
+	public List<Message> createMessages(Map<String, Object> model) {
+		List<Message> messages = new ArrayList<>();
+		for (PromptTemplate promptTemplate : promptTemplates) {
+			messages.addAll(promptTemplate.createMessages(model));
+		}
+		return messages;
 	}
 
 	@Override
 	public Prompt create() {
-		return new Prompt(new ChatMessage(this.messageType, render()));
+		List<Message> messages = createMessages();
+		return new Prompt(messages);
 	}
 
 	@Override
 	public Prompt create(Map<String, Object> model) {
-		return new Prompt(new ChatMessage(this.messageType, render(model)));
+		List<Message> messages = createMessages(model);
+		return new Prompt(messages);
 	}
 
 }

spring-ai-core/src/main/java/org/springframework/ai/core/prompt/OutputParser.java

@@ -16,6 +16,8 @@
 
 package org.springframework.ai.core.prompt;
 
+import org.springframework.ai.core.llm.Generation;
+
 import java.util.List;
 
 public interface OutputParser {

spring-ai-core/src/main/java/org/springframework/ai/core/prompt/PromptTemplate.java

@@ -18,25 +18,30 @@
 
 import org.antlr.runtime.Token;
 import org.antlr.runtime.TokenStream;
+import org.springframework.ai.core.prompt.messages.Message;
+import org.springframework.ai.core.prompt.messages.UserMessage;
 import org.stringtemplate.v4.ST;
 import org.stringtemplate.v4.compiler.STLexer;
 
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.Map;
+import java.util.*;
 import java.util.Map.Entry;
-import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 
-public class PromptTemplate extends AbstractPromptTemplate {
+public class PromptTemplate implements PromptTemplateActions {
 
 	private ST st;
 
 	private Map<String, Object> dynamicModel = new HashMap<>();
 
+	protected String template;
+
+	protected TemplateFormat templateFormat = TemplateFormat.ST;
+
+	private OutputParser outputParser;
+
 	public PromptTemplate(String template) {
-		super(template);
+		this.template = template;
 		// If the template string is not valid, an exception will be thrown
 		try {
 			this.st = new ST(this.template, '{', '}');
@@ -46,12 +51,42 @@ public PromptTemplate(String template) {
 		}
 	}
 
-	@Override
+	public PromptTemplate(String template, Map<String, Object> model) {
+		this.template = template;
+		// If the template string is not valid, an exception will be thrown
+		try {
+			this.st = new ST(this.template, '{', '}');
+			for (Entry<String, Object> entry : model.entrySet()) {
+				add(entry.getKey(), entry.getValue());
+			}
+		}
+		catch (Exception ex) {
+			throw new IllegalArgumentException("The template string is not valid.", ex);
+		}
+	}
+
+	public OutputParser getOutputParser() {
+		return outputParser;
+	}
+
+	public void setOutputParser(OutputParser outputParser) {
+		Objects.requireNonNull(outputParser, "Output Parser can not be null");
+		this.outputParser = outputParser;
+	}
+
 	public void add(String name, Object value) {
 		this.st.add(name, value);
 		this.dynamicModel.put(name, value);
 	}
 
+	public String getTemplate() {
+		return this.template;
+	}
+
+	public TemplateFormat getTemplateFormat() {
+		return this.templateFormat;
+	}
+
 	// Render Methods
 	public String render() {
 		return st.render();
@@ -68,6 +103,16 @@ public String render(Map<String, Object> model) {
 		return st.render().trim();
 	}
 
+	@Override
+	public List<Message> createMessages() {
+		return List.of(new UserMessage(render()));
+	}
+
+	@Override
+	public List<Message> createMessages(Map<String, Object> model) {
+		return List.of(new UserMessage(render(model)));
+	}
+
 	@Override
 	public Prompt create() {
 		return new Prompt(render(new HashMap<>()));

spring-ai-core/src/main/java/org/springframework/ai/core/prompt/PromptOperations.java → spring-ai-core/src/main/java/org/springframework/ai/core/prompt/PromptTemplateActions.java

@@ -16,20 +16,21 @@
 
 package org.springframework.ai.core.prompt;
 
-import java.util.Map;
-
-public interface PromptOperations {
-
-	String getTemplate();
+import org.springframework.ai.core.prompt.messages.Message;
 
-	TemplateFormat getTemplateFormat();
+import java.util.List;
+import java.util.Map;
 
-	void add(String name, Object value);
+public interface PromptTemplateActions {
 
 	String render();
 
 	String render(Map<String, Object> model);
 
+	List<Message> createMessages();
+
+	List<Message> createMessages(Map<String, Object> model);
+
 	Prompt create();
 
 	Prompt create(Map<String, Object> model);