updated data extraction for for changes

lib/chains/data_extraction_chain.ex

@@ -72,6 +72,7 @@ defmodule LangChain.Chains.DataExtractionChain do
   require Logger
   alias LangChain.PromptTemplate
   alias LangChain.Message
+  alias LangChain.Message.ToolCall
   alias LangChain.Chains.LLMChain
 
   @function_name "information_extraction"
@@ -101,15 +102,19 @@ Passage:
       {:ok, chain} = LLMChain.new(%{llm: llm, verbose: verbose})
 
       chain
-      |> LLMChain.add_functions(build_extract_function(json_schema))
+      |> LLMChain.add_tools(build_extract_function(json_schema))
       |> LLMChain.add_messages(messages)
       |> LLMChain.run()
       |> case do
         {:ok, _updated_chain,
          %Message{
            role: :assistant,
-           function_name: @function_name,
-           arguments: %{"info" => info}
+           tool_calls: [
+             %ToolCall{
+               name: @function_name,
+               arguments: %{"info" => info}
+             }
+           ]
          }}
         when is_list(info) ->
           {:ok, info}
@@ -136,6 +141,12 @@ Passage:
     LangChain.Function.new!(%{
       name: @function_name,
       description: "Extracts the relevant information from the passage.",
+      function: fn args, _context ->
+        # NOTE: The function is not executed here because we won't be returning
+        # this to the LLM. The LLMChain does not run the function, but stops at
+        # the request for it.
+        {:ok, args}
+      end,
       parameters_schema: %{
         type: "object",
         properties: %{