Flatten messages in PromptBuilder

core/src/commonMain/kotlin/com/xebia/functional/xef/prompt/PromptBuilder.kt

@@ -23,25 +23,37 @@ interface PromptBuilder {
 
   @JvmSynthetic
   operator fun Message.unaryPlus() {
-    items.add(this)
+    addMessage(this)
   }
 
   @JvmSynthetic
   operator fun List<Message>.unaryPlus() {
-    items.addAll(this)
+    addMessages(this)
   }
 
-  fun addPrompt(prompt: Prompt): PromptBuilder = apply { items.addAll(prompt.messages) }
+  fun addPrompt(prompt: Prompt): PromptBuilder = apply { addMessages(prompt.messages) }
 
-  fun addMessage(message: Message): PromptBuilder = apply { items.add(message) }
+  fun addSystemMessage(message: String): PromptBuilder = apply { addMessage(system(message)) }
 
-  fun addSystemMessage(message: String): PromptBuilder = apply { items.add(system(message)) }
+  fun addAssistantMessage(message: String): PromptBuilder = apply { addMessage(assistant(message)) }
 
-  fun addAssistantMessage(message: String): PromptBuilder = apply { items.add(assistant(message)) }
+  fun addUserMessage(message: String): PromptBuilder = apply { addMessage(user(message)) }
 
-  fun addUserMessage(message: String): PromptBuilder = apply { items.add(user(message)) }
+  fun addMessage(message: Message): PromptBuilder = apply {
+    val lastMessageWithSameRole: Message? = items.lastMessageWithSameRole(message)
+    if (lastMessageWithSameRole != null) {
+      val messageUpdated = lastMessageWithSameRole.addContent(message)
+      items.remove(lastMessageWithSameRole)
+      items.add(messageUpdated)
+    } else {
+      items.add(message)
+    }
+  }
 
-  fun addMessages(messages: List<Message>): PromptBuilder = apply { items.addAll(messages) }
+  fun addMessages(messages: List<Message>): PromptBuilder = apply {
+    val last = items.removeLastOrNull()
+    items.addAll(((last?.let { listOf(it) } ?: emptyList()) + messages).flatten())
+  }
 
   companion object {
 
@@ -53,3 +65,22 @@ fun String.message(role: Role): Message = Message(role, this, role.name)
 
 inline fun <reified A> A.message(role: Role): Message =
   Message(role, Json.encodeToString(serializer(), this), role.name)
+
+private fun List<Message>.flatten(): List<Message> =
+  fold(mutableListOf()) { acc, message ->
+    val lastMessageWithSameRole: Message? = acc.lastMessageWithSameRole(message)
+    if (lastMessageWithSameRole != null) {
+      val messageUpdated = lastMessageWithSameRole.addContent(message)
+      acc.remove(lastMessageWithSameRole)
+      acc.add(messageUpdated)
+    } else {
+      acc.add(message)
+    }
+    acc
+  }
+
+private fun Message.addContent(message: Message): Message =
+  copy(content = "${content}\n${message.content}")
+
+private fun List<Message>.lastMessageWithSameRole(message: Message): Message? =
+  lastOrNull()?.let { if (it.role == message.role) it else null }

core/src/commonMain/kotlin/com/xebia/functional/xef/prompt/templates/templates.kt

@@ -2,8 +2,6 @@ package com.xebia.functional.xef.prompt.templates
 
 import com.xebia.functional.xef.llm.models.chat.Message
 import com.xebia.functional.xef.llm.models.chat.Role
-import com.xebia.functional.xef.prompt.PlatformPromptBuilder
-import com.xebia.functional.xef.prompt.Prompt
 import com.xebia.functional.xef.prompt.message
 
 fun system(context: String): Message = context.message(Role.SYSTEM)
@@ -18,14 +16,14 @@ inline fun <reified A> assistant(data: A): Message = data.message(Role.ASSISTANT
 
 inline fun <reified A> user(data: A): Message = data.message(Role.USER)
 
-class StepsMessageBuilder : PlatformPromptBuilder() {
+fun steps(role: Role, content: () -> List<String>): Message =
+  content().mapIndexed { ix, elt -> "${ix + 1} - $elt" }.joinToString("\n").message(role)
 
-  override fun preprocess(elements: List<Message>): List<Message> =
-    elements.mapIndexed { ix, elt -> "${ix + 1} - ${elt.content}".message(elt.role) }
-}
+fun systemSteps(content: () -> List<String>): Message = steps(Role.SYSTEM, content)
+
+fun assistantSteps(content: () -> List<String>): Message = steps(Role.ASSISTANT, content)
 
-fun steps(inside: StepsMessageBuilder.() -> Unit): Prompt =
-  StepsMessageBuilder().apply { inside() }.build()
+fun userSteps(content: () -> List<String>): Message = steps(Role.USER, content)
 
 fun writeSequenceOf(
   content: String,

core/src/commonTest/kotlin/com/xebia/functional/xef/prompt/PromptBuilderSpec.kt

@@ -2,10 +2,7 @@ package com.xebia.functional.xef.prompt
 
 import com.xebia.functional.xef.data.Question
 import com.xebia.functional.xef.llm.models.chat.Role
-import com.xebia.functional.xef.prompt.templates.assistant
-import com.xebia.functional.xef.prompt.templates.steps
-import com.xebia.functional.xef.prompt.templates.system
-import com.xebia.functional.xef.prompt.templates.user
+import com.xebia.functional.xef.prompt.templates.*
 import io.kotest.core.spec.style.StringSpec
 import io.kotest.matchers.shouldBe
 
@@ -45,8 +42,12 @@ class PromptBuilderSpec :
         listOf(
           "Test System".message(Role.SYSTEM),
           "Test Query".message(Role.USER),
-          "instruction 1".message(Role.ASSISTANT),
-          "instruction 2".message(Role.ASSISTANT)
+          """
+            |instruction 1
+            |instruction 2
+        """
+            .trimMargin()
+            .message(Role.ASSISTANT),
         )
 
       messages shouldBe messagesExpected
@@ -59,16 +60,20 @@ class PromptBuilderSpec :
         Prompt {
             +system("Test System")
             +user("Test Query")
-            +steps { instructions.forEach { +assistant(it) } }
+            +assistantSteps { instructions }
           }
           .messages
 
       val messagesExpected =
         listOf(
           "Test System".message(Role.SYSTEM),
           "Test Query".message(Role.USER),
-          "1 - instruction 1".message(Role.ASSISTANT),
-          "2 - instruction 2".message(Role.ASSISTANT)
+          """
+            |1 - instruction 1
+            |2 - instruction 2
+        """
+            .trimMargin()
+            .message(Role.ASSISTANT),
         )
 
       messages shouldBe messagesExpected
@@ -92,4 +97,41 @@ class PromptBuilderSpec :
 
       messages shouldBe messagesExpected
     }
+
+    "Prompt should flatten the messages with the same role" {
+      val messages =
+        Prompt {
+            +system("Test System")
+            +user("User message 1")
+            +user("User message 2")
+            +assistant("Assistant message 1")
+            +user("User message 3")
+            +assistant("Assistant message 2")
+            +assistant("Assistant message 3")
+            +user("User message 4")
+          }
+          .messages
+
+      val messagesExpected =
+        listOf(
+          "Test System".message(Role.SYSTEM),
+          """
+            |User message 1
+            |User message 2
+          """
+            .trimMargin()
+            .message(Role.USER),
+          "Assistant message 1".message(Role.ASSISTANT),
+          "User message 3".message(Role.USER),
+          """
+                |Assistant message 2
+                |Assistant message 3
+            """
+            .trimMargin()
+            .message(Role.ASSISTANT),
+          "User message 4".message(Role.USER),
+        )
+
+      messages shouldBe messagesExpected
+    }
   })

reasoning/src/commonMain/kotlin/com/xebia/functional/xef/reasoning/text/summarize/Summarize.kt

@@ -5,8 +5,7 @@ import com.xebia.functional.tokenizer.truncateText
 import com.xebia.functional.xef.conversation.Conversation
 import com.xebia.functional.xef.llm.Chat
 import com.xebia.functional.xef.prompt.Prompt
-import com.xebia.functional.xef.prompt.templates.assistant
-import com.xebia.functional.xef.prompt.templates.steps
+import com.xebia.functional.xef.prompt.templates.assistantSteps
 import com.xebia.functional.xef.prompt.templates.system
 import com.xebia.functional.xef.prompt.templates.user
 import com.xebia.functional.xef.reasoning.tools.Tool
@@ -60,12 +59,11 @@ class Summarize(
               """
           .trimMargin()
       )
-      +steps {
-        (listOf(
-            "Summarize the `text` in max $summaryLength words",
-            "Reply with an empty response: ` ` if the text can't be summarized"
-          ) + instructions)
-          .forEach { +assistant(it) }
+      +assistantSteps {
+        listOf(
+          "Summarize the `text` in max $summaryLength words",
+          "Reply with an empty response: ` ` if the text can't be summarized"
+        ) + instructions
       }
     }
 

reasoning/src/jvmMain/kotlin/com/xebia/functional/xef/reasoning/filesystem/ProduceTextFile.kt

@@ -4,10 +4,7 @@ import com.xebia.functional.xef.conversation.Conversation
 import com.xebia.functional.xef.io.DEFAULT
 import com.xebia.functional.xef.llm.ChatWithFunctions
 import com.xebia.functional.xef.prompt.Prompt
-import com.xebia.functional.xef.prompt.templates.assistant
-import com.xebia.functional.xef.prompt.templates.steps
-import com.xebia.functional.xef.prompt.templates.system
-import com.xebia.functional.xef.prompt.templates.user
+import com.xebia.functional.xef.prompt.templates.*
 import com.xebia.functional.xef.reasoning.tools.Tool
 import kotlinx.uuid.UUID
 import kotlinx.uuid.generateUUID
@@ -29,7 +26,7 @@ class ProduceTextFile(
           Prompt {
             +system("Convert output for a Text File")
             +user(input)
-            +steps { instructions.forEach { +assistant(it) } }
+            +assistantSteps { instructions }
           },
         scope = scope,
         serializer = TxtFile.serializer()