feat(lint): add too_many_instance_attributes rule

crates/erg_linter/warn.rs

@@ -1,5 +1,6 @@
 use erg_common::error::{ErrorCore, ErrorKind, Location, SubMessage};
 use erg_common::io::Input;
+use erg_common::switch_lang;
 use erg_common::traits::NoTypeDisplay;
 use erg_compiler::error::CompileWarning;
 use erg_compiler::hir::Expr;
@@ -18,6 +19,38 @@ pub(crate) fn too_many_params(input: Input, caused_by: String, loc: Location) ->
     )
 }
 
+pub(crate) fn too_many_instance_attributes(
+    input: Input,
+    caused_by: String,
+    loc: Location,
+) -> CompileWarning {
+    let msg = switch_lang!(
+            "japanese" => "インスタンス属性が多すぎます",
+            "simplified_chinese" => "实例属性过多",
+            "traditional_chinese" => "實例屬性過多",
+            "english" => "too many instance attributes",
+    )
+    .to_string();
+    let hint = switch_lang!(
+            "japanese" => "サブクラスやデータクラスを活用してください",
+            "simplified_chinese" => "利用子类和数据类",
+            "traditional_chinese" => "利用子類和資料類",
+            "english" => "take advantage of subclasses and data classes",
+    )
+    .to_string();
+    CompileWarning::new(
+        ErrorCore::new(
+            vec![SubMessage::ambiguous_new(loc, vec![], Some(hint))],
+            msg,
+            0,
+            ErrorKind::AttributeWarning,
+            loc,
+        ),
+        input,
+        caused_by,
+    )
+}
+
 pub(crate) fn true_comparison(
     expr: &Expr,
     input: Input,