feat: update argument handling logic

Author: lemorage

examples/image_search/main.py

@@ -69,18 +69,17 @@ def image_object_embedding_flow(
     )
     img_embeddings = data_scope.add_collector()
     with data_scope["images"].row() as img:
-        caption_ds = img["content"].transform(
+        img["caption"] = flow_builder.transform(
             cocoindex.functions.ExtractByLlm(
-                llm_spec=cocoindex.llm.LlmSpec(
-                    api_type=cocoindex.LlmApiType.OLLAMA,
-                    model="llama3.1",
+                llm_spec=cocoindex.LlmSpec(
+                    api_type=cocoindex.LlmApiType.GEMINI, model="gemini-2.0-flash"
                 ),
-                # Replace by this spec below, to use OpenAI API model instead of ollama
+                # Replace by this spec below, to use OpenAI API model instead of gemini
                 #   llm_spec=cocoindex.LlmSpec(
                 #       api_type=cocoindex.LlmApiType.OPENAI, model="gpt-4o"),
-                # Replace by this spec below, to use Gemini API model
-                #   llm_spec=cocoindex.LlmSpec(
-                #       api_type=cocoindex.LlmApiType.GEMINI, model="gemini-2.0-flash"),
+                # Replace by this spec below, to use Ollama API model
+                #   llm_spec=cocoindex.llm.LlmSpec(
+                #       api_type=cocoindex.LlmApiType.OLLAMA, model="llama3.1"),
                 # Replace by this spec below, to use Anthropic API model
                 #   llm_spec=cocoindex.LlmSpec(
                 #       api_type=cocoindex.LlmApiType.ANTHROPIC, model="claude-3-5-sonnet-latest"),
@@ -91,14 +90,15 @@ def image_object_embedding_flow(
                     "Mention what each animal is doing."
                 ),
                 output_type=str,
-            )
+            ),
+            image=img["content"],
         )
-        embedding_ds = img["content"].transform(embed_image)
+        img["embedding"] = img["content"].transform(embed_image)
         img_embeddings.collect(
             id=cocoindex.GeneratedField.UUID,
             filename=img["filename"],
-            caption=caption_ds,
-            embedding=embedding_ds,
+            caption=img["caption"],
+            embedding=img["embedding"],
         )
 
     img_embeddings.export(

src/ops/functions/extract_by_llm.rs

@@ -130,28 +130,17 @@ impl SimpleFunctionFactoryBase for Factory {
         args_resolver: &mut OpArgsResolver<'a>,
         _context: &FlowInstanceContext,
     ) -> Result<(Args, EnrichedValueType)> {
-        let mut args = Args {
-            text: None,
-            image: None,
-        };
-
-        // Handle positional argument
-        if let Some(arg) = args_resolver.next_optional_arg("")? {
-            match arg.typ.typ {
-                ValueType::Basic(BasicValueType::Str) => args.text = Some(arg),
-                ValueType::Basic(BasicValueType::Bytes) => args.image = Some(arg),
-                _ => api_bail!(
-                    "Positional argument must be of type 'Str' or 'Bytes', got {}",
-                    arg.typ.typ
-                ),
-            }
-        }
-
-        if args.text.is_none() && args.image.is_none() {
-            api_bail!("At least one of 'text' or 'image' must be provided");
-        }
-
-        Ok((args, spec.output_type.clone()))
+        Ok((
+            Args {
+                text: args_resolver
+                    .next_optional_arg("text")?
+                    .expect_type(&ValueType::Basic(BasicValueType::Str))?,
+                image: args_resolver
+                    .next_optional_arg("image")?
+                    .expect_type(&ValueType::Basic(BasicValueType::Bytes))?,
+            },
+            spec.output_type.clone(),
+        ))
     }
 
     async fn build_executor(