Python-codegen arrow serilization of structs of datatypes

crates/re_types_builder/src/codegen/python/mod.rs

@@ -1821,13 +1821,43 @@ fn quote_arrow_support_from_obj(
 /// Only implemented for some cases.
 fn quote_arrow_serialization(
  _reporter: &Reporter,
- _objects: &Objects,
+ objects: &Objects,
  obj: &Object,
 ) -> Result<String, String> {
  let Object { name, .. } = obj;
 
  match obj.class {
- ObjectClass::Struct => Err("We lack codegen for arrow-serialization of structs".to_owned()),
+ ObjectClass::Struct => {
+ let mut code = String::new();
+
+ code.push_indented(0, "from .. import datatypes", 2);
+
+ code.push_indented(0, &format!("if isinstance(data, {name}):"), 1);
+ code.push_indented(1, "data = [data]", 2);
+
+ code.push_indented(0, "return pa.StructArray.from_arrays(", 1);
+ code.push_indented(1, "[", 1);
+ for field in &obj.fields {
+ let Type::Object(field_fqname) = &field.typ else {
+ return Err(
+ "We lack codegen for arrow-serialization of general structs".to_owned()
+ );
+ };
+ let field_obj = &objects[field_fqname];
+ let field_type_name = &field_obj.name;
+ let field_name = &field.name;
+ let field_batch_type = format!("datatypes.{field_type_name}Batch");
+ let field_array = format!("[x.{field_name} for x in data]");
+ let field_fwd =
+ format!("{field_batch_type}({field_array}).as_arrow_array().storage,");
+ code.push_indented(2, &field_fwd, 1);
+ }
+ code.push_indented(1, "],", 1);
+ code.push_indented(1, "fields=list(data_type),", 1);
+ code.push_indented(0, ")", 1);
+
+ Ok(code)
+ }
 
  ObjectClass::Enum => {
  // Generate case-insensitive string-to-enum conversion: