Refactor CFunction to work with String schemas instead of KotlinX (#207)

core/src/commonMain/kotlin/com/xebia/functional/xef/llm/openai/functions/CFunction.kt

@@ -1,7 +1,55 @@
 package com.xebia.functional.xef.llm.openai.functions
 
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.KSerializer
 import kotlinx.serialization.Serializable
-import kotlinx.serialization.json.JsonObject
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
+import kotlinx.serialization.json.JsonEncoder
+import kotlinx.serialization.json.JsonUnquotedLiteral
 
+/*
+"functions": [
+    {
+      "name": "get_current_weather",
+      "description": "Get the current weather in a given location",
+      "parameters": {
+        "type": "object",
+        "properties": {
+          "location": {
+            "type": "string",
+            "description": "The city and state, e.g. San Francisco, CA"
+          },
+          "unit": {
+            "type": "string",
+            "enum": ["celsius", "fahrenheit"]
+          }
+        },
+        "required": ["location"]
+      }
+    }
+  ]
+ */
 @Serializable
-data class CFunction(val name: String, val description: String, val parameters: JsonObject)
+data class CFunction(val name: String, val description: String, val parameters: RawJsonString)
+
+typealias RawJsonString = @Serializable(with = RawJsonStringSerializer::class) String
+
+@OptIn(ExperimentalSerializationApi::class)
+private object RawJsonStringSerializer : KSerializer<String> {
+  override val descriptor =
+    PrimitiveSerialDescriptor(
+      "com.xebia.functional.xef.llm.openai.functions.RawJsonString",
+      PrimitiveKind.STRING
+    )
+
+  override fun deserialize(decoder: Decoder): String = decoder.decodeString()
+
+  override fun serialize(encoder: Encoder, value: String) =
+    when (encoder) {
+      is JsonEncoder -> encoder.encodeJsonElement(JsonUnquotedLiteral(value))
+      else -> encoder.encodeString(value)
+    }
+}

kotlin/src/commonMain/kotlin/com/xebia/functional/xef/auto/DeserializerLLMAgent.kt

@@ -1,10 +1,13 @@
 package com.xebia.functional.xef.auto
 
-import com.xebia.functional.xef.auto.serialization.functions.encodeFunctionSchema
+import com.xebia.functional.xef.auto.serialization.encodeJsonSchema
 import com.xebia.functional.xef.llm.openai.LLMModel
+import com.xebia.functional.xef.llm.openai.functions.CFunction
 import com.xebia.functional.xef.prompt.Prompt
+import kotlinx.serialization.ExperimentalSerializationApi
 import kotlinx.serialization.KSerializer
 import kotlinx.serialization.SerializationException
+import kotlinx.serialization.descriptors.SerialDescriptor
 import kotlinx.serialization.json.Json
 import kotlinx.serialization.serializer
 
@@ -96,7 +99,7 @@ suspend fun <A> AIScope.prompt(
   bringFromContext: Int = this.docsInContext,
   minResponseTokens: Int = this.minResponseTokens,
 ): A {
-  val functions = encodeFunctionSchema(serializer.descriptor)
+  val functions = generateCFunction(serializer.descriptor)
   return prompt(
     prompt,
     functions,
@@ -111,3 +114,9 @@ suspend fun <A> AIScope.prompt(
     minResponseTokens
   )
 }
+
+@OptIn(ExperimentalSerializationApi::class)
+private fun generateCFunction(descriptor: SerialDescriptor): List<CFunction> {
+  val fnName = descriptor.serialName.substringAfterLast(".")
+  return listOf(CFunction(fnName, "Generated function for $fnName", encodeJsonSchema(descriptor)))
+}

kotlin/src/commonMain/kotlin/com/xebia/functional/xef/auto/serialization/JsonSchema.kt

@@ -117,7 +117,7 @@ fun encodeJsonSchema(descriptor: SerialDescriptor): String =
   Json.encodeToString(JsonObject.serializer(), buildJsonSchema(descriptor))
 
 /** Creates a Json Schema using the provided [descriptor] */
-internal fun buildJsonSchema(descriptor: SerialDescriptor): JsonObject {
+private fun buildJsonSchema(descriptor: SerialDescriptor): JsonObject {
   val autoDefinitions = false
   val prepend = mapOf("\$schema" to JsonPrimitive("http://json-schema.org/draft-07/schema"))
   val definitions = JsonSchemaDefinitions(autoDefinitions)

scala/src/main/scala/com/xebia/functional/xef/scala/auto/package.scala

@@ -8,7 +8,7 @@ import io.circe.Decoder
 import io.circe.parser.parse
 import com.xebia.functional.xef.auto.AIKt
 import com.xebia.functional.xef.auto.AIRuntime
-import com.xebia.functional.xef.auto.serialization.functions.FunctionSchemaKt
+import com.xebia.functional.xef.auto.serialization.JsonSchemaKt
 import com.xebia.functional.xef.pdf.PDFLoaderKt
 import com.xebia.functional.tokenizer.ModelType
 import com.xebia.functional.xef.llm.openai._
@@ -54,7 +54,7 @@ def prompt[A: Decoder: SerialDescriptor](
   LoomAdapter.apply((cont) =>
     scope.kt.promptWithSerializer[A](
       prompt,
-      FunctionSchemaKt.encodeFunctionSchema(SerialDescriptor[A].serialDescriptor),
+      generateCFunctions.asJava,
       (json: String) => parse(json).flatMap(Decoder[A].decodeJson(_)).fold(throw _, identity),
       maxAttempts,
       llmModel,
@@ -68,6 +68,12 @@ def prompt[A: Decoder: SerialDescriptor](
     )
   )
 
+private def generateCFunctions[A: SerialDescriptor]: List[CFunction] =
+  val descriptor = SerialDescriptor[A].serialDescriptor
+  val serialName = descriptor.getSerialName
+  val fnName = serialName.substring(serialName.lastIndexOf("."), serialName.length)
+  List(CFunction(fnName, "Generated function for $fnName", JsonSchemaKt.encodeJsonSchema(descriptor)))
+
 def contextScope[A: Decoder: SerialDescriptor](docs: List[String])(block: AI[A])(using scope: AIScope): A =
   LoomAdapter.apply(scope.kt.contextScopeWithDocs[A](docs.asJava, (_, _) => block, _))