Allow string pairs as input to text classification serving

lib/bumblebee/shared.ex

@@ -210,6 +210,14 @@ defmodule Bumblebee.Shared do
     end
   end
 
+  def validate_string_or_pairs(input) do
+    case input do
+      input when is_binary(input) -> {:ok, input}
+      {left, right} when is_binary(left) and is_binary(right) -> {:ok, input}
+      _other -> {:error, "expected a string or a pair of strings, got: #{inspect(input)}"}
+    end
+  end
+
   @doc """
   Validates that the input is a single value and not a batch.
   """

lib/bumblebee/text.ex

@@ -288,7 +288,7 @@ defmodule Bumblebee.Text do
   defdelegate translation(model_info, tokenizer, generation_config, opts \\ []),
     to: Bumblebee.Text.Translation
 
-  @type text_classification_input :: String.t()
+  @type text_classification_input :: String.t() | {String.t(), String.t()}
   @type text_classification_output :: %{predictions: list(text_classification_prediction())}
   @type text_classification_prediction :: %{score: number(), label: String.t()}
 

lib/bumblebee/text/text_classification.ex

@@ -74,7 +74,7 @@ defmodule Bumblebee.Text.TextClassification do
     |> Nx.Serving.batch_size(batch_size)
     |> Nx.Serving.process_options(batch_keys: batch_keys)
     |> Nx.Serving.client_preprocessing(fn input ->
-      {texts, multi?} = Shared.validate_serving_input!(input, &Shared.validate_string/1)
+      {texts, multi?} = Shared.validate_serving_input!(input, &Shared.validate_string_or_pairs/1)
 
       inputs =
         Nx.with_default_backend(Nx.BinaryBackend, fn ->