Merge pull request #70 from media-io/extend_flatten_support

Extend Flatten support

yaserde/tests/de_flatten.rs

@@ -0,0 +1,166 @@
+#[macro_use]
+extern crate yaserde_derive;
+
+use std::io::Read;
+use yaserde::de::from_str;
+use yaserde::YaDeserialize;
+
+macro_rules! convert_and_validate {
+  ($content: expr, $struct: tt, $model: expr) => {
+    let loaded: Result<$struct, String> = from_str($content);
+    assert_eq!(loaded, Ok($model));
+  };
+}
+
+#[test]
+fn de_root_flatten_struct() {
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  #[yaserde(flatten)]
+  struct Content {
+    binary_data: String,
+    string_data: String,
+  }
+
+  let content = r#"
+    <?xml version="1.0" encoding="utf-8"?>
+    <binary_data>binary</binary_data>
+    <string_data>string</string_data>
+  "#;
+
+  convert_and_validate!(
+    content,
+    Content,
+    Content {
+      binary_data: "binary".to_string(),
+      string_data: "string".to_string(),
+    }
+  );
+}
+
+#[test]
+fn de_root_flatten_enum() {
+  #[derive(PartialEq, Debug, YaDeserialize)]
+  #[yaserde(flatten)]
+  pub enum Content {
+    Binary(Binary),
+    Data(Data),
+    Unknown,
+  }
+
+  impl Default for Content {
+    fn default() -> Self {
+      Content::Unknown
+    }
+  }
+
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  pub struct Binary {
+    binary_data: String,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  pub struct Data {
+    string_data: String,
+  }
+
+  let content = r#"
+    <?xml version="1.0" encoding="utf-8"?>
+    <Binary>
+      <binary_data>binary</binary_data>
+    </Binary>
+  "#;
+
+  convert_and_validate!(
+    content,
+    Content,
+    Content::Binary(Binary {
+      binary_data: "binary".to_string(),
+    })
+  );
+}
+
+#[test]
+fn de_flatten() {
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  struct DateTime {
+    #[yaserde(flatten)]
+    date: Date,
+    time: String,
+    #[yaserde(flatten)]
+    kind: DateKind,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  struct Date {
+    year: i32,
+    month: i32,
+    day: i32,
+    #[yaserde(flatten)]
+    extra: Extra,
+    #[yaserde(flatten)]
+    optional_extra: Option<OptionalExtra>,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  pub struct Extra {
+    week: i32,
+    century: i32,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaDeserialize)]
+  pub struct OptionalExtra {
+    lunar_day: i32,
+  }
+
+  #[derive(PartialEq, Debug, YaDeserialize)]
+  pub enum DateKind {
+    #[yaserde(rename = "holidays")]
+    Holidays(Vec<String>),
+    #[yaserde(rename = "working")]
+    Working,
+  }
+
+  impl Default for DateKind {
+    fn default() -> Self {
+      DateKind::Working
+    }
+  };
+
+  let content = r#"
+    <?xml version="1.0" encoding="utf-8"?>
+    <DateTime>
+      <year>2020</year>
+      <month>1</month>
+      <day>1</day>
+      <week>1</week>
+      <century>21</century>
+      <lunar_day>1</lunar_day>
+      <time>10:40:03</time>
+      <holidays>New Year's Day</holidays>
+      <holidays>Novy God Day</holidays>
+      <holidays>Polar Bear Swim Day</holidays>
+    </DateTime>
+  "#;
+  convert_and_validate!(
+    content,
+    DateTime,
+    DateTime {
+      date: Date {
+        year: 2020,
+        month: 1,
+        day: 1,
+        extra: Extra {
+          week: 1,
+          century: 21,
+        },
+        optional_extra: Some(OptionalExtra { lunar_day: 1 }),
+      },
+      time: "10:40:03".to_string(),
+      kind: DateKind::Holidays(vec![
+        "New Year's Day".into(),
+        "Novy God Day".into(),
+        "Polar Bear Swim Day".into()
+      ])
+    }
+  );
+}

yaserde/tests/deserializer.rs

@@ -691,92 +691,6 @@ fn de_custom() {
   );
 }
 
-#[test]
-fn de_flatten() {
-  #[derive(Default, PartialEq, Debug, YaDeserialize)]
-  struct DateTime {
-    #[yaserde(flatten)]
-    date: Date,
-    time: String,
-    #[yaserde(flatten)]
-    kind: DateKind,
-  }
-
-  #[derive(Default, PartialEq, Debug, YaDeserialize)]
-  struct Date {
-    year: i32,
-    month: i32,
-    day: i32,
-    #[yaserde(flatten)]
-    extra: Extra,
-    #[yaserde(flatten)]
-    optional_extra: Option<OptionalExtra>,
-  }
-
-  #[derive(Default, PartialEq, Debug, YaDeserialize)]
-  pub struct Extra {
-    week: i32,
-    century: i32,
-  }
-
-  #[derive(Default, PartialEq, Debug, YaDeserialize)]
-  pub struct OptionalExtra {
-    lunar_day: i32,
-  }
-
-  #[derive(PartialEq, Debug, YaDeserialize)]
-  pub enum DateKind {
-    #[yaserde(rename = "holidays")]
-    Holidays(Vec<String>),
-    #[yaserde(rename = "working")]
-    Working,
-  }
-
-  impl Default for DateKind {
-    fn default() -> Self {
-      DateKind::Working
-    }
-  };
-
-  let content = r#"
-    <?xml version="1.0" encoding="utf-8"?>
-    <DateTime>
-      <year>2020</year>
-      <month>1</month>
-      <day>1</day>
-      <week>1</week>
-      <century>21</century>
-      <lunar_day>1</lunar_day>
-      <time>10:40:03</time>
-      <holidays>New Year's Day</holidays>
-      <holidays>Novy God Day</holidays>
-      <holidays>Polar Bear Swim Day</holidays>
-    </DateTime>
-  "#;
-  convert_and_validate!(
-    content,
-    DateTime,
-    DateTime {
-      date: Date {
-        year: 2020,
-        month: 1,
-        day: 1,
-        extra: Extra {
-          week: 1,
-          century: 21,
-        },
-        optional_extra: Some(OptionalExtra { lunar_day: 1 }),
-      },
-      time: "10:40:03".to_string(),
-      kind: DateKind::Holidays(vec![
-        "New Year's Day".into(),
-        "Novy God Day".into(),
-        "Polar Bear Swim Day".into()
-      ])
-    }
-  );
-}
-
 #[test]
 fn de_subitem_issue_12() {
   #[derive(Default, PartialEq, Debug, YaDeserialize)]

yaserde/tests/ser_flatten.rs

@@ -0,0 +1,156 @@
+#[macro_use]
+extern crate yaserde_derive;
+
+use std::io::Write;
+use yaserde::ser::to_string;
+use yaserde::YaSerialize;
+
+macro_rules! convert_and_validate {
+  ($model: expr, $content: expr) => {
+    let data: Result<String, String> = to_string(&$model);
+    assert_eq!(
+      data,
+      Ok(
+        String::from($content)
+          .split("\n")
+          .map(|s| s.trim())
+          .collect::<String>()
+      )
+    );
+  };
+}
+
+#[test]
+fn ser_flatten() {
+  #[derive(Default, PartialEq, Debug, YaSerialize)]
+  struct DateTime {
+    #[yaserde(flatten)]
+    date: Date,
+    time: String,
+    #[yaserde(flatten)]
+    kind: DateKind,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaSerialize)]
+  struct Date {
+    year: i32,
+    month: i32,
+    day: i32,
+    #[yaserde(flatten)]
+    extra: Extra,
+    #[yaserde(flatten)]
+    optional_extra: Option<OptionalExtra>,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaSerialize)]
+  pub struct Extra {
+    week: i32,
+    century: i32,
+  }
+
+  #[derive(Default, PartialEq, Debug, YaSerialize)]
+  pub struct OptionalExtra {
+    lunar_day: i32,
+  }
+
+  #[derive(PartialEq, Debug, YaSerialize)]
+  pub enum DateKind {
+    #[yaserde(rename = "holidays")]
+    Holidays(Vec<String>),
+    #[yaserde(rename = "working")]
+    Working,
+  }
+
+  impl Default for DateKind {
+    fn default() -> Self {
+      DateKind::Working
+    }
+  };
+
+  let model = DateTime {
+    date: Date {
+      year: 2020,
+      month: 1,
+      day: 1,
+      extra: Extra {
+        week: 1,
+        century: 21,
+      },
+      optional_extra: Some(OptionalExtra { lunar_day: 1 }),
+    },
+    time: "10:40:03".to_string(),
+    kind: DateKind::Holidays(vec![
+      "New Year's Day".into(),
+      "Novy God Day".into(),
+      "Polar Bear Swim Day".into(),
+    ]),
+  };
+
+  let content = r#"
+    <?xml version="1.0" encoding="utf-8"?>
+    <DateTime>
+      <year>2020</year>
+      <month>1</month>
+      <day>1</day>
+      <week>1</week>
+      <century>21</century>
+      <lunar_day>1</lunar_day>
+      <time>10:40:03</time>
+      <holidays>New Year's Day</holidays>
+      <holidays>Novy God Day</holidays>
+      <holidays>Polar Bear Swim Day</holidays>
+    </DateTime>"#;
+
+  convert_and_validate!(model, content);
+}
+
+#[test]
+fn ser_root_flatten_struct() {
+  #[derive(YaSerialize, PartialEq, Debug)]
+  #[yaserde(flatten)]
+  pub struct Content {
+    binary_data: String,
+    string_data: String,
+  }
+
+  let model = Content {
+    binary_data: "binary".to_string(),
+    string_data: "string".to_string(),
+  };
+  let content = r#"<?xml version="1.0" encoding="utf-8"?><binary_data>binary</binary_data><string_data>string</string_data>"#;
+  convert_and_validate!(model, content);
+}
+
+#[test]
+fn ser_root_flatten_enum() {
+  #[derive(YaSerialize, PartialEq, Debug)]
+  #[yaserde(flatten)]
+  pub enum Content {
+    Binary(Binary),
+    Data(Data),
+  }
+
+  #[derive(YaSerialize, PartialEq, Debug)]
+  pub struct Binary {
+    binary_data: String,
+  }
+
+  #[derive(YaSerialize, PartialEq, Debug)]
+  pub struct Data {
+    string_data: String,
+  }
+
+  let model = Content::Binary(Binary {
+    binary_data: "binary".to_string(),
+  });
+  let content =
+    r#"<?xml version="1.0" encoding="utf-8"?><Binary><binary_data>binary</binary_data></Binary>"#;
+  convert_and_validate!(model, content);
+
+  let model = Content::Data(Data {
+    string_data: "string".to_string(),
+  });
+  let content =
+    r#"<?xml version="1.0" encoding="utf-8"?><Data><string_data>string</string_data></Data>"#;
+  convert_and_validate!(model, content);
+}

yaserde/tests/serializer.rs

@@ -329,87 +329,3 @@ fn ser_custom() {
   let content = "<?xml version=\"1.0\" encoding=\"utf-8\"?><Date><Year>2020</Year><Month>1</Month><DoubleDay>10</DoubleDay></Date>";
   convert_and_validate!(model, content);
 }
-
-#[test]
-fn ser_flatten() {
-  #[derive(Default, PartialEq, Debug, YaSerialize)]
-  struct DateTime {
-    #[yaserde(flatten)]
-    date: Date,
-    time: String,
-    #[yaserde(flatten)]
-    kind: DateKind,
-  }
-
-  #[derive(Default, PartialEq, Debug, YaSerialize)]
-  struct Date {
-    year: i32,
-    month: i32,
-    day: i32,
-    #[yaserde(flatten)]
-    extra: Extra,
-    #[yaserde(flatten)]
-    optional_extra: Option<OptionalExtra>,
-  }
-
-  #[derive(Default, PartialEq, Debug, YaSerialize)]
-  pub struct Extra {
-    week: i32,
-    century: i32,
-  }
-
-  #[derive(Default, PartialEq, Debug, YaSerialize)]
-  pub struct OptionalExtra {
-    lunar_day: i32,
-  }
-
-  #[derive(PartialEq, Debug, YaSerialize)]
-  pub enum DateKind {
-    #[yaserde(rename = "holidays")]
-    Holidays(Vec<String>),
-    #[yaserde(rename = "working")]
-    Working,
-  }
-
-  impl Default for DateKind {
-    fn default() -> Self {
-      DateKind::Working
-    }
-  };
-
-  let model = DateTime {
-    date: Date {
-      year: 2020,
-      month: 1,
-      day: 1,
-      extra: Extra {
-        week: 1,
-        century: 21,
-      },
-      optional_extra: Some(OptionalExtra { lunar_day: 1 }),
-    },
-    time: "10:40:03".to_string(),
-    kind: DateKind::Holidays(vec![
-      "New Year's Day".into(),
-      "Novy God Day".into(),
-      "Polar Bear Swim Day".into(),
-    ]),
-  };
-
-  let content = r#"
-    <?xml version="1.0" encoding="utf-8"?>
-    <DateTime>
-      <year>2020</year>
-      <month>1</month>
-      <day>1</day>
-      <week>1</week>
-      <century>21</century>
-      <lunar_day>1</lunar_day>
-      <time>10:40:03</time>
-      <holidays>New Year's Day</holidays>
-      <holidays>Novy God Day</holidays>
-      <holidays>Polar Bear Swim Day</holidays>
-    </DateTime>"#;
-
-  convert_and_validate!(model, content);
-}

yaserde_derive/src/de/expand_enum.rs

@@ -1,7 +1,6 @@
 use crate::attribute::*;
 use crate::field_type::*;
 use proc_macro2::TokenStream;
-use std::collections::BTreeMap;
 use syn::spanned::Spanned;
 use syn::DataEnum;
 use syn::Fields;
@@ -11,7 +10,7 @@ pub fn parse(
   data_enum: &DataEnum,
   name: &Ident,
   root: &str,
-  _namespaces: &BTreeMap<String, String>,
+  root_attributes: &YaSerdeAttribute,
 ) -> TokenStream {
   let match_to_enum: TokenStream = data_enum
     .variants
@@ -20,6 +19,8 @@ pub fn parse(
     .filter_map(|f| f)
     .collect();
 
+  let flatten = root_attributes.flatten;
+
   quote! {
     use xml::reader::XmlEvent;
     use yaserde::Visitor;
@@ -47,7 +48,7 @@ pub fn parse(
 
               match name.local_name.as_str() {
                 #match_to_enum
-                named_element => {
+                _named_element => {
                   let _root = reader.next_event();
                 }
               }
@@ -68,6 +69,13 @@ pub fn parse(
             XmlEvent::Characters(ref text_content) => {
               let _root = reader.next_event();
             }
+            XmlEvent::EndDocument => {
+              if #flatten {
+                break;
+              }
+
+              return Err(format!("End of document, missing some content ?"))
+            }
             event => {
               return Err(format!("unknown event {:?}", event))
             }

yaserde_derive/src/de/expand_struct.rs

@@ -11,13 +11,13 @@ pub fn parse(
   data_struct: &DataStruct,
   name: &Ident,
   root: &str,
-  prefix: &Option<String>,
-  namespaces: &BTreeMap<String, String>,
+  root_attributes: &YaSerdeAttribute,
 ) -> TokenStream {
-  let namespaces_matches: TokenStream = namespaces
+  let namespaces_matches: TokenStream = root_attributes
+    .namespaces
     .iter()
     .map(|(p, ns)| {
-      if prefix.as_ref() == Some(p) {
+      if root_attributes.prefix.as_ref() == Some(p) {
         Some(quote!(#ns => {}))
       } else {
         None
@@ -199,7 +199,7 @@ pub fn parse(
           &action,
           &field_attrs,
           label,
-          &namespaces,
+          &root_attributes.namespaces,
           field.span(),
         )
       };
@@ -368,6 +368,8 @@ pub fn parse(
     build_code_for_unused_xml_events(&call_flatten_visitors)
   };
 
+  let flatten = root_attributes.flatten;
+
   quote! {
     use xml::reader::{XmlEvent, EventReader};
     use xml::writer::EventWriter;
@@ -407,7 +409,6 @@ pub fn parse(
 
         loop {
           let event = reader.peek()?.to_owned();
-
           match event {
             XmlEvent::StartElement{ref name, ref attributes, ..} => {
               let mut skipped = false;
@@ -443,6 +444,11 @@ pub fn parse(
               #write_unused
               depth -= 1;
             }
+            XmlEvent::EndDocument => {
+              if #flatten {
+                break;
+              }
+            }
             XmlEvent::Characters(ref text_content) => {
               #set_text
               let event = reader.next_event()?;

yaserde_derive/src/de/mod.rs

@@ -16,16 +16,10 @@ pub fn expand_derive_deserialize(ast: &syn::DeriveInput) -> Result<TokenStream,
   let root = root_attrs.clone().root.unwrap_or_else(|| name.to_string());
 
   let impl_block = match *data {
-    syn::Data::Struct(ref data_struct) => expand_struct::parse(
-      data_struct,
-      name,
-      &root,
-      &root_attrs.prefix,
-      &root_attrs.namespaces,
-    ),
-    syn::Data::Enum(ref data_enum) => {
-      expand_enum::parse(data_enum, name, &root, &root_attrs.namespaces)
+    syn::Data::Struct(ref data_struct) => {
+      expand_struct::parse(data_struct, name, &root, &root_attrs)
     }
+    syn::Data::Enum(ref data_enum) => expand_enum::parse(data_enum, name, &root, &root_attrs),
     syn::Data::Union(ref _data_union) => unimplemented!(),
   };
 

yaserde_derive/src/ser/expand_enum.rs

@@ -1,7 +1,6 @@
 use crate::attribute::*;
 use crate::field_type::*;
 use proc_macro2::TokenStream;
-use std::collections::BTreeMap;
 use syn::spanned::Spanned;
 use syn::DataEnum;
 use syn::Fields;
@@ -11,8 +10,7 @@ pub fn serialize(
   data_enum: &DataEnum,
   name: &Ident,
   root: &str,
-  namespaces: &BTreeMap<String, String>,
-  default_namespace: &Option<String>,
+  root_attributes: &YaSerdeAttribute,
 ) -> TokenStream {
   let write_enum_content: TokenStream = data_enum
     .variants
@@ -224,10 +222,11 @@ pub fn serialize(
     .filter_map(|x| x)
     .collect();
 
-  let add_namespaces: TokenStream = namespaces
+  let add_namespaces: TokenStream = root_attributes
+    .namespaces
     .iter()
     .map(|(prefix, namespace)| {
-      if let Some(dn) = default_namespace {
+      if let Some(dn) = &root_attributes.default_namespace {
         if dn == prefix {
           return Some(quote!(
             .default_ns(#namespace)
@@ -241,6 +240,8 @@ pub fn serialize(
     .filter_map(|x| x)
     .collect();
 
+  let flatten = root_attributes.flatten;
+
   quote! {
     use xml::writer::XmlEvent;
 
@@ -250,7 +251,7 @@ pub fn serialize(
         -> Result<(), String> {
         let skip = writer.skip_start_end();
 
-        if !skip {
+        if !#flatten && !skip {
           if let Some(label) = writer.get_start_event_name() {
             let struct_start_event = XmlEvent::start_element(label.as_ref());
             writer.write(struct_start_event).map_err(|e| e.to_string())?;
@@ -264,7 +265,7 @@ pub fn serialize(
           #write_enum_content
         }
 
-        if !skip {
+        if !#flatten && !skip {
           let struct_end_event = XmlEvent::end_element();
           writer.write(struct_end_event).map_err(|e| e.to_string())?;
         }

yaserde_derive/src/ser/expand_struct.rs

@@ -2,7 +2,6 @@ use crate::attribute::*;
 use crate::field_type::*;
 use crate::ser::element::*;
 use proc_macro2::TokenStream;
-use std::collections::BTreeMap;
 use std::string::ToString;
 use syn::spanned::Spanned;
 use syn::DataStruct;
@@ -12,8 +11,7 @@ pub fn serialize(
   data_struct: &DataStruct,
   name: &Ident,
   root: &str,
-  namespaces: &BTreeMap<String, String>,
-  default_namespace: &Option<String>,
+  root_attributes: &YaSerdeAttribute,
 ) -> TokenStream {
   let build_attributes: TokenStream = data_struct
     .fields
@@ -26,7 +24,7 @@ pub fn serialize(
 
       let label = &field.ident;
 
-      let label_name = build_label_name(&field, &field_attrs, default_namespace);
+      let label_name = build_label_name(&field, &field_attrs, &root_attributes.default_namespace);
 
       get_field_type(field).and_then(|f| match f {
         FieldType::FieldTypeString
@@ -205,10 +203,11 @@ pub fn serialize(
     .filter_map(|x| x)
     .collect();
 
-  let add_namespaces: TokenStream = namespaces
+  let add_namespaces: TokenStream = root_attributes
+    .namespaces
     .iter()
     .map(|(prefix, namespace)| {
-      if let Some(dn) = default_namespace {
+      if let Some(dn) = &root_attributes.default_namespace {
         if dn == prefix {
           return Some(quote!(
             .default_ns(#namespace)
@@ -239,7 +238,7 @@ pub fn serialize(
         ));
       }
 
-      let label_name = build_label_name(&field, &field_attrs, default_namespace);
+      let label_name = build_label_name(&field, &field_attrs, &root_attributes.default_namespace);
       let conditions = condition_generator(label, &field_attrs);
 
       get_field_type(field).and_then(|f| match f {
@@ -381,6 +380,8 @@ pub fn serialize(
     .filter_map(|x| x)
     .collect();
 
+  let flatten = root_attributes.flatten;
+
   quote! {
     use xml::writer::XmlEvent;
 
@@ -390,7 +391,7 @@ pub fn serialize(
         -> Result<(), String> {
         let skip = writer.skip_start_end();
 
-        if !skip {
+        if !#flatten && !skip {
           let yaserde_label = writer.get_start_event_name().unwrap_or_else(|| #root.to_string());
           let struct_start_event = XmlEvent::start_element(yaserde_label.as_ref())#add_namespaces;
           #build_attributes
@@ -399,7 +400,7 @@ pub fn serialize(
 
         #struct_inspector
 
-        if !skip {
+        if !#flatten && !skip {
           let struct_end_event = XmlEvent::end_element();
           writer.write(struct_end_event).map_err(|e| e.to_string())?;
         }

yaserde_derive/src/ser/mod.rs

@@ -2,7 +2,7 @@ pub mod element;
 pub mod expand_enum;
 pub mod expand_struct;
 
-use crate::attribute;
+use crate::attribute::YaSerdeAttribute;
 use proc_macro2::TokenStream;
 use syn;
 use syn::Ident;
@@ -12,13 +12,14 @@ pub fn expand_derive_serialize(ast: &syn::DeriveInput) -> Result<TokenStream, St
   let attrs = &ast.attrs;
   let data = &ast.data;
 
-  let root_attrs = attribute::YaSerdeAttribute::parse(attrs);
+  let root_attrs = YaSerdeAttribute::parse(attrs);
   let root = root_attrs.clone().root.unwrap_or_else(|| name.to_string());
 
   let prefix = if root_attrs.default_namespace == root_attrs.prefix {
     "".to_string()
   } else {
     root_attrs
+      .clone()
       .prefix
       .map_or("".to_string(), |prefix| prefix + ":")
   };
@@ -26,20 +27,10 @@ pub fn expand_derive_serialize(ast: &syn::DeriveInput) -> Result<TokenStream, St
   let root = format!("{}{}", prefix, root);
 
   let impl_block = match *data {
-    syn::Data::Struct(ref data_struct) => expand_struct::serialize(
-      data_struct,
-      name,
-      &root,
-      &root_attrs.namespaces,
-      &root_attrs.default_namespace,
-    ),
-    syn::Data::Enum(ref data_enum) => expand_enum::serialize(
-      data_enum,
-      name,
-      &root,
-      &root_attrs.namespaces,
-      &root_attrs.default_namespace,
-    ),
+    syn::Data::Struct(ref data_struct) => {
+      expand_struct::serialize(data_struct, name, &root, &root_attrs)
+    }
+    syn::Data::Enum(ref data_enum) => expand_enum::serialize(data_enum, name, &root, &root_attrs),
     syn::Data::Union(ref _data_union) => unimplemented!(),
   };