diff --git a/build.rs b/build.rs
index bb438f0c5..96aa2273a 100644
--- a/build.rs
+++ b/build.rs
@@ -14,6 +14,6 @@ fn main() -> std::io::Result<()> {
         version.micro.unwrap_or(0)
     );
     let magic_number = env_magic_number();
-    println!("cargo:rustc-env=PYTHON_MAGIC_NUMBER={}", magic_number);
+    println!("cargo:rustc-env=PYTHON_MAGIC_NUMBER={magic_number}");
     Ok(())
 }
diff --git a/crates/els/hover.rs b/crates/els/hover.rs
index fbbe6e3a0..54c7fc2f4 100644
--- a/crates/els/hover.rs
+++ b/crates/els/hover.rs
@@ -84,7 +84,7 @@ impl<Checker: BuildRunnable> Server<Checker> {
                             let relative = relative
                                 .strip_prefix(self.erg_path.to_str().unwrap())
                                 .unwrap_or(relative);
-                            format!("# {}, line {line}\n", relative)
+                            format!("# {relative}, line {line}\n")
                         };
                         // display the definition line
                         if vi.kind.is_defined() {
diff --git a/crates/els/server.rs b/crates/els/server.rs
index 504e4868c..94ff3ae4d 100644
--- a/crates/els/server.rs
+++ b/crates/els/server.rs
@@ -201,7 +201,7 @@ impl<Checker: BuildRunnable> Server<Checker> {
             if res.len() != 2 {
                 return Err(io::Error::new(
                     io::ErrorKind::InvalidData,
-                    format!("Header '{}' is malformed", buffer),
+                    format!("Header '{buffer}' is malformed"),
                 ));
             }
             let header_name = res[0].to_lowercase();
@@ -217,7 +217,7 @@ impl<Checker: BuildRunnable> Server<Checker> {
                     if header_value != "utf8" && header_value != "utf-8" {
                         return Err(io::Error::new(
                             io::ErrorKind::InvalidData,
-                            format!("Content type '{}' is invalid", header_value),
+                            format!("Content type '{header_value}' is invalid"),
                         ));
                     }
                 }
@@ -291,7 +291,7 @@ impl<Checker: BuildRunnable> Server<Checker> {
                 self.check_file(uri, &code)
             }
             // "textDocument/didChange"
-            _ => Self::send_log(format!("received notification: {}", method)),
+            _ => Self::send_log(format!("received notification: {method}")),
         }
     }
 
diff --git a/crates/erg_common/config.rs b/crates/erg_common/config.rs
index c904239ce..6d8e1c3f0 100644
--- a/crates/erg_common/config.rs
+++ b/crates/erg_common/config.rs
@@ -618,7 +618,7 @@ USAGE:
                 }
                 _ => {
                     let path = PathBuf::from_str(&arg[..])
-                        .unwrap_or_else(|_| panic!("invalid file path: {}", arg));
+                        .unwrap_or_else(|_| panic!("invalid file path: {arg}"));
                     let path = normalize_path(path);
                     cfg.input = Input::File(path);
                     if let Some("--") = args.next().as_ref().map(|s| &s[..]) {
diff --git a/crates/erg_common/error.rs b/crates/erg_common/error.rs
index fc402de4b..668aa064e 100644
--- a/crates/erg_common/error.rs
+++ b/crates/erg_common/error.rs
@@ -374,10 +374,7 @@ fn format_context<E: ErrorDisplay + ?Sized>(
     let (vbreak, vbar) = chars.gutters();
     let offset = format!("{} {} ", &" ".repeat(max_digit), vbreak);
     for (i, lineno) in (ln_begin..=ln_end).enumerate() {
-        context.push_str_with_color(
-            &format!("{:<max_digit$} {vbar} ", lineno, vbar = vbar),
-            gutter_color,
-        );
+        context.push_str_with_color(&format!("{lineno:<max_digit$} {vbar} "), gutter_color);
         context.push_str(codes.get(i).unwrap_or(&String::new()));
         context.push_str("\n");
         context.push_str_with_color(&offset, gutter_color);
@@ -578,7 +575,7 @@ impl SubMessage {
                         .remove(0)
                 };
                 let mut cxt = StyledStrings::default();
-                cxt.push_str_with_color(&format!(" {lineno} {} ", vbar), gutter_color);
+                cxt.push_str_with_color(&format!(" {lineno} {vbar} "), gutter_color);
                 cxt.push_str(&code);
                 cxt.push_str("\n");
                 for msg in self.msg.iter() {
@@ -597,7 +594,7 @@ impl SubMessage {
                 other => {
                     let (_, vbar) = chars.gutters();
                     let mut cxt = StyledStrings::default();
-                    cxt.push_str_with_color(&format!(" ? {} ", vbar), gutter_color);
+                    cxt.push_str_with_color(&format!(" ? {vbar} "), gutter_color);
                     cxt.push_str(&other.reread());
                     cxt.push_str("\n");
                     for msg in self.msg.iter() {
diff --git a/crates/erg_common/style.rs b/crates/erg_common/style.rs
index 07b824e0e..64db7a54a 100644
--- a/crates/erg_common/style.rs
+++ b/crates/erg_common/style.rs
@@ -348,7 +348,7 @@ impl StyledString {
 }
 
 impl std::fmt::Display for StyledString {
-    fn fmt<'a>(&self, f: &mut std::fmt::Formatter<'a>) -> std::fmt::Result {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match (self.color, self.attribute) {
             (None, None) => write!(f, "{}", self.text),
             (None, Some(attr)) => write!(f, "{}{}{}", attr.as_str(), self.text, ATTR_RESET),
@@ -493,7 +493,7 @@ impl StyledStrings {
 impl std::fmt::Display for StyledStrings {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
         for text in self.texts.iter() {
-            write!(f, "{}", text)?;
+            write!(f, "{text}")?;
         }
         Ok(())
     }
@@ -563,6 +563,6 @@ mod tests {
             Color::Red,
             Attribute::Reversed,
         );
-        println!("{}", texts);
+        println!("{texts}");
     }
 }
diff --git a/crates/erg_compiler/context/initialize/const_func.rs b/crates/erg_compiler/context/initialize/const_func.rs
index 92ef96eca..58a5e7cc7 100644
--- a/crates/erg_compiler/context/initialize/const_func.rs
+++ b/crates/erg_compiler/context/initialize/const_func.rs
@@ -290,7 +290,7 @@ pub fn __range_getitem__(mut args: ValueArgs, _ctx: &Context) -> EvalValueResult
     } else {
         Err(ErrorCore::new(
             vec![SubMessage::only_loc(Location::Unknown)],
-            format!("Index out of range: {}", index),
+            format!("Index out of range: {index}"),
             line!() as usize,
             ErrorKind::IndexError,
             Location::Unknown,
diff --git a/crates/erg_compiler/context/initialize/mod.rs b/crates/erg_compiler/context/initialize/mod.rs
index 748fec6b3..1c1d54ab8 100644
--- a/crates/erg_compiler/context/initialize/mod.rs
+++ b/crates/erg_compiler/context/initialize/mod.rs
@@ -780,7 +780,7 @@ impl Context {
         muty: Mutability,
     ) {
         if self.patches.contains_key(name) {
-            panic!("{} has already been registered", name);
+            panic!("{name} has already been registered");
         } else {
             let name = VarName::from_static(name);
             let vi = VarInfo::new(
diff --git a/crates/erg_compiler/error/lower.rs b/crates/erg_compiler/error/lower.rs
index de339061a..900524bee 100644
--- a/crates/erg_compiler/error/lower.rs
+++ b/crates/erg_compiler/error/lower.rs
@@ -127,8 +127,8 @@ impl LowerError {
         found_t: &Type,
     ) -> Self {
         let name = StyledString::new(readable_name(name), Some(WARN), None);
-        let expect = StyledString::new(format!("{}", spec_t), Some(HINT), Some(ATTR));
-        let found = StyledString::new(format!("{}", found_t), Some(ERR), Some(ATTR));
+        let expect = StyledString::new(format!("{spec_t}"), Some(HINT), Some(ATTR));
+        let found = StyledString::new(format!("{found_t}"), Some(ERR), Some(ATTR));
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::only_loc(loc)],
@@ -522,7 +522,7 @@ impl LowerError {
         caused_by: S,
     ) -> Self {
         let name = StyledString::new(name, Some(ERR), Some(ATTR));
-        let superclass = StyledString::new(format!("{}", superclass), Some(WARN), Some(ATTR));
+        let superclass = StyledString::new(format!("{superclass}"), Some(WARN), Some(ATTR));
         let hint = Some(
             switch_lang!(
                 "japanese" => {
@@ -854,7 +854,7 @@ impl LowerError {
         hint: Option<String>,
     ) -> Self {
         let name = StyledString::new(name, Some(WARN), Some(ATTR));
-        let found = StyledString::new(format!("{}", cast_to), Some(ERR), Some(ATTR));
+        let found = StyledString::new(format!("{cast_to}"), Some(ERR), Some(ATTR));
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::ambiguous_new(loc, vec![], hint)],
diff --git a/crates/erg_compiler/error/tycheck.rs b/crates/erg_compiler/error/tycheck.rs
index 07a78e2bc..e9c945d5d 100644
--- a/crates/erg_compiler/error/tycheck.rs
+++ b/crates/erg_compiler/error/tycheck.rs
@@ -127,7 +127,7 @@ impl TyCheckError {
             ),
             None => "".to_owned(),
         };
-        let name = StyledString::new(format!("{}{}", name, ord), Some(WARN), Some(ATTR));
+        let name = StyledString::new(format!("{name}{ord}"), Some(WARN), Some(ATTR));
         let mut expct = StyledStrings::default();
         switch_lang!(
             "japanese" => expct.push_str("予期した型: "),
@@ -135,7 +135,7 @@ impl TyCheckError {
             "traditional_chinese" => expct.push_str("預期: "),
             "english" => expct.push_str("expected: "),
         );
-        expct.push_str_with_color_and_attribute(format!("{}", expect), HINT, ATTR);
+        expct.push_str_with_color_and_attribute(format!("{expect}"), HINT, ATTR);
 
         let mut fnd = StyledStrings::default();
         switch_lang!(
@@ -144,7 +144,7 @@ impl TyCheckError {
             "traditional_chinese" => fnd.push_str("但找到: "),
             "english" =>fnd.push_str("but found: "),
         );
-        fnd.push_str_with_color_and_attribute(format!("{}", found), ERR, ATTR);
+        fnd.push_str_with_color_and_attribute(format!("{found}"), ERR, ATTR);
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::ambiguous_new(
@@ -183,7 +183,7 @@ impl TyCheckError {
             "traditional_chinese" => expct.push_str("預期: "),
             "english" => expct.push_str("expected: "),
         );
-        expct.push_str_with_color_and_attribute(format!("{}", expect), HINT, ATTR);
+        expct.push_str_with_color_and_attribute(format!("{expect}"), HINT, ATTR);
 
         let mut fnd = StyledStrings::default();
         switch_lang!(
@@ -192,7 +192,7 @@ impl TyCheckError {
             "traditional_chinese" => fnd.push_str("但找到: "),
             "english" =>fnd.push_str("but found: "),
         );
-        fnd.push_str_with_color_and_attribute(format!("{}", found), ERR, ATTR);
+        fnd.push_str_with_color_and_attribute(format!("{found}"), ERR, ATTR);
 
         Self::new(
             ErrorCore::new(
@@ -257,7 +257,7 @@ impl TyCheckError {
             "traditional_chinese" => expct.push_str("預期: "),
             "english" => expct.push_str("expected: "),
         );
-        expct.push_str_with_color_and_attribute(format!("{}", expect), HINT, ATTR);
+        expct.push_str_with_color_and_attribute(format!("{expect}"), HINT, ATTR);
 
         let mut fnd = StyledStrings::default();
         switch_lang!(
@@ -266,7 +266,7 @@ impl TyCheckError {
             "traditional_chinese" => fnd.push_str("但找到: "),
             "english" =>fnd.push_str("but found: "),
         );
-        fnd.push_str_with_color_and_attribute(format!("{}", found), ERR, ATTR);
+        fnd.push_str_with_color_and_attribute(format!("{found}"), ERR, ATTR);
 
         Self::new(
             ErrorCore::new(
@@ -305,7 +305,7 @@ impl TyCheckError {
             "traditional_chinese" => expct.push_str("預期: "),
             "english" => expct.push_str("expected: "),
         );
-        expct.push_str_with_color_and_attribute(format!("{}", expect), HINT, ATTR);
+        expct.push_str_with_color_and_attribute(format!("{expect}"), HINT, ATTR);
 
         let mut fnd = StyledStrings::default();
         switch_lang!(
@@ -314,7 +314,7 @@ impl TyCheckError {
             "traditional_chinese" => fnd.push_str("但找到: "),
             "english" =>fnd.push_str("but found: "),
         );
-        fnd.push_str_with_color_and_attribute(format!("{}", found), ERR, ATTR);
+        fnd.push_str_with_color_and_attribute(format!("{found}"), ERR, ATTR);
 
         Self::new(
             ErrorCore::new(
@@ -433,9 +433,9 @@ impl TyCheckError {
         kw_args_len: usize,
     ) -> Self {
         let name = readable_name(callee_name);
-        let expect = StyledString::new(format!("{}", params_len), Some(HINT), Some(ATTR));
-        let pos_args_len = StyledString::new(format!("{}", pos_args_len), Some(ERR), Some(ATTR));
-        let kw_args_len = StyledString::new(format!("{}", kw_args_len), Some(ERR), Some(ATTR));
+        let expect = StyledString::new(format!("{params_len}"), Some(HINT), Some(ATTR));
+        let pos_args_len = StyledString::new(format!("{pos_args_len}"), Some(ERR), Some(ATTR));
+        let kw_args_len = StyledString::new(format!("{kw_args_len}"), Some(ERR), Some(ATTR));
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::only_loc(loc)],
@@ -576,7 +576,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => lhs_typ.push_str("左邊: "),
             "english" => lhs_typ.push_str("lhs: "),
         );
-        lhs_typ.push_str_with_color_and_attribute(format!("{}", lhs_t), WARN, ATTR);
+        lhs_typ.push_str_with_color_and_attribute(format!("{lhs_t}"), WARN, ATTR);
         let mut rhs_typ = StyledStrings::default();
         switch_lang!(
             "japanese" => rhs_typ.push_str("右辺: "),
@@ -584,7 +584,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => rhs_typ.push_str("右邊: "),
             "english" => rhs_typ.push_str("rhs: "),
         );
-        rhs_typ.push_str_with_color_and_attribute(format!("{}", rhs_t), WARN, ATTR);
+        rhs_typ.push_str_with_color_and_attribute(format!("{rhs_t}"), WARN, ATTR);
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::ambiguous_new(
@@ -622,7 +622,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => lhs_typ.push_str("左邊: "),
             "english" => lhs_typ.push_str("lhs: "),
         );
-        lhs_typ.push_str_with_color_and_attribute(format!("{}", lhs_t), WARN, ATTR);
+        lhs_typ.push_str_with_color_and_attribute(format!("{lhs_t}"), WARN, ATTR);
         let mut rhs_typ = StyledStrings::default();
         switch_lang!(
             "japanese" => rhs_typ.push_str("右辺: "),
@@ -630,7 +630,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => rhs_typ.push_str("右邊: "),
             "english" => rhs_typ.push_str("rhs: "),
         );
-        rhs_typ.push_str_with_color_and_attribute(format!("{}", rhs_t), WARN, ATTR);
+        rhs_typ.push_str_with_color_and_attribute(format!("{rhs_t}"), WARN, ATTR);
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::ambiguous_new(
@@ -668,7 +668,7 @@ passed keyword args:    {kw_args_len}"
             "simplified_chinese" =>sub_type.push_str("子類型:"),
             "english" => sub_type.push_str("subtype: "),
         );
-        sub_type.push_str_with_color_and_attribute(format!("{}", sub_t), HINT, ATTR);
+        sub_type.push_str_with_color_and_attribute(format!("{sub_t}"), HINT, ATTR);
 
         let mut sup_type = StyledStrings::default();
         switch_lang!(
@@ -677,7 +677,7 @@ passed keyword args:    {kw_args_len}"
             "simplified_chinese" => sup_type.push_str("父類型: "),
             "english" =>sup_type.push_str("supertype: "),
         );
-        sup_type.push_str_with_color_and_attribute(format!("{}", sup_t), ERR, ATTR);
+        sup_type.push_str_with_color_and_attribute(format!("{sup_t}"), ERR, ATTR);
         let hint = switch_lang!(
             "japanese" => "型推論が失敗している可能性があります。型を明示的に指定してみてください。",
             "simplified_chinese" => "可能是编译器推断失败。请尝试明确指定类型。",
@@ -720,7 +720,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => lhs_uni.push_str("左邊: "),
             "english" => lhs_uni.push_str("lhs: "),
         );
-        lhs_uni.push_str_with_color_and_attribute(format!("{}", lhs), HINT, ATTR);
+        lhs_uni.push_str_with_color_and_attribute(format!("{lhs}"), HINT, ATTR);
         let mut rhs_uni = StyledStrings::default();
         switch_lang!(
             "japanese" => rhs_uni.push_str("右辺: "),
@@ -728,7 +728,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => rhs_uni.push_str("右邊: "),
             "english" => rhs_uni.push_str("rhs: "),
         );
-        rhs_uni.push_str_with_color_and_attribute(format!("{}", rhs), ERR, ATTR);
+        rhs_uni.push_str_with_color_and_attribute(format!("{rhs}"), ERR, ATTR);
         Self::new(
             ErrorCore::new(
                 vec![SubMessage::ambiguous_new(
@@ -854,23 +854,23 @@ passed keyword args:    {kw_args_len}"
         let mut expct = StyledStrings::default();
         switch_lang!(
             "japanese" => {
-                expct.push_str_with_color_and_attribute(format!("{}", trait_type), ACCENT, ATTR);
+                expct.push_str_with_color_and_attribute(format!("{trait_type}"), ACCENT, ATTR);
                 expct.push_str("で宣言された型: ");
             },
             "simplified_chinese" => {
-                expct.push_str_with_color_and_attribute(format!("{}", trait_type), ACCENT, ATTR);
+                expct.push_str_with_color_and_attribute(format!("{trait_type}"), ACCENT, ATTR);
                 expct.push_str("中声明的类型: ");
             },
             "traditional_chinese" => {
-                expct.push_str_with_color_and_attribute(format!("{}", trait_type), ACCENT, ATTR);
+                expct.push_str_with_color_and_attribute(format!("{trait_type}"), ACCENT, ATTR);
                 expct.push_str("中聲明的類型: ");
             },
             "english" => {
                 expct.push_str("declared in ");
-                expct.push_str_with_color(format!("{}: ", trait_type), ACCENT);
+                expct.push_str_with_color(format!("{trait_type}: "), ACCENT);
             },
         );
-        expct.push_str_with_color(format!("{}", expect), HINT);
+        expct.push_str_with_color(format!("{expect}"), HINT);
         let mut fnd = StyledStrings::default();
         switch_lang!(
             "japanese" => fnd.push_str("与えられた型: "),
@@ -878,7 +878,7 @@ passed keyword args:    {kw_args_len}"
             "traditional_chinese" => fnd.push_str("但找到: "),
             "english" => fnd.push_str("but found: "),
         );
-        fnd.push_str_with_color(format!("{}", found), ERR);
+        fnd.push_str_with_color(format!("{found}"), ERR);
         let member_name = StyledStr::new(member_name, Some(WARN), Some(ATTR));
         Self::new(
             ErrorCore::new(
diff --git a/crates/erg_compiler/hir.rs b/crates/erg_compiler/hir.rs
index babebe87b..fc0e1d856 100644
--- a/crates/erg_compiler/hir.rs
+++ b/crates/erg_compiler/hir.rs
@@ -394,7 +394,7 @@ impl NestedDisplay for Identifier {
             }
         }
         if let Some(qn) = &self.qual_name {
-            write!(f, "(qual_name: {})", qn)?;
+            write!(f, "(qual_name: {qn})")?;
         }
         if self.vi.t != Type::Uninited {
             write!(f, "(: {})", self.vi.t)?;
diff --git a/crates/erg_compiler/ty/codeobj.rs b/crates/erg_compiler/ty/codeobj.rs
index 3aa7391e0..27a97e926 100644
--- a/crates/erg_compiler/ty/codeobj.rs
+++ b/crates/erg_compiler/ty/codeobj.rs
@@ -489,7 +489,7 @@ impl CodeObj {
     fn read_instr_308(&self, op: &u8, arg: &u8, idx: usize, instrs: &mut String) {
         let op308 = Opcode308::from(*op);
         let s_op = op308.to_string();
-        write!(instrs, "{:>15} {:<25}", idx, s_op).unwrap();
+        write!(instrs, "{idx:>15} {s_op:<25}").unwrap();
         if let Ok(op) = CommonOpcode::try_from(*op) {
             self.dump_additional_info(op, arg, idx, instrs);
         }
@@ -531,7 +531,7 @@ impl CodeObj {
     fn read_instr_310(&self, op: &u8, arg: &u8, idx: usize, instrs: &mut String) {
         let op310 = Opcode310::from(*op);
         let s_op = op310.to_string();
-        write!(instrs, "{:>15} {:<25}", idx, s_op).unwrap();
+        write!(instrs, "{idx:>15} {s_op:<25}").unwrap();
         if let Ok(op) = CommonOpcode::try_from(*op) {
             self.dump_additional_info(op, arg, idx, instrs);
         }
diff --git a/crates/erg_compiler/ty/deserialize.rs b/crates/erg_compiler/ty/deserialize.rs
index 3970d70b1..aa64648f9 100644
--- a/crates/erg_compiler/ty/deserialize.rs
+++ b/crates/erg_compiler/ty/deserialize.rs
@@ -258,10 +258,10 @@ impl Deserializer {
                 0,
                 fn_name!(),
                 switch_lang!(
-                    "japanese" => format!("このオブジェクトは復元できません: {}", other),
-                    "simplified_chinese" => format!("无法反序列化此对象: {}", other),
-                    "traditional_chinese" => format!("無法反序列化此對象: {}", other),
-                    "english" => format!("cannot deserialize this object: {}", other),
+                    "japanese" => format!("このオブジェクトは復元できません: {other}"),
+                    "simplified_chinese" => format!("无法反序列化此对象: {other}"),
+                    "traditional_chinese" => format!("無法反序列化此對象: {other}"),
+                    "english" => format!("cannot deserialize this object: {other}"),
                 ),
             )),
         }
diff --git a/crates/erg_compiler/ty/mod.rs b/crates/erg_compiler/ty/mod.rs
index f8bda602d..47364d808 100644
--- a/crates/erg_compiler/ty/mod.rs
+++ b/crates/erg_compiler/ty/mod.rs
@@ -149,13 +149,13 @@ impl fmt::Display for ParamTy {
         match self {
             Self::Pos { name, ty } => {
                 if let Some(name) = name {
-                    write!(f, "{}", name)?;
+                    write!(f, "{name}")?;
                 }
-                write!(f, ": {}", ty)
+                write!(f, ": {ty}")
             }
-            Self::Kw { name, ty } => write!(f, "{}: {}", name, ty),
+            Self::Kw { name, ty } => write!(f, "{name}: {ty}"),
             Self::KwWithDefault { name, ty, default } => {
-                write!(f, "{}: {} := {}", name, ty, default)
+                write!(f, "{name}: {ty} := {default}")
             }
         }
     }
@@ -397,7 +397,7 @@ impl LimitedDisplay for RefinementType {
             write!(f, "{{")?;
             for pred in self.preds.iter() {
                 let (_, rhs) = enum_unwrap!(pred, Predicate::Equal { lhs, rhs });
-                write!(f, "{}, ", rhs)?;
+                write!(f, "{rhs}, ")?;
             }
             write!(f, "}}")?;
             if cfg!(feature = "debug") {
diff --git a/crates/erg_compiler/ty/typaram.rs b/crates/erg_compiler/ty/typaram.rs
index 14157d8f6..a668375f9 100644
--- a/crates/erg_compiler/ty/typaram.rs
+++ b/crates/erg_compiler/ty/typaram.rs
@@ -246,16 +246,16 @@ impl LimitedDisplay for TyParam {
             Self::Type(t) => t.limited_fmt(f, limit - 1),
             Self::FreeVar(fv) => fv.limited_fmt(f, limit - 1),
             Self::UnaryOp { op, val } => {
-                write!(f, "{}", op)?;
+                write!(f, "{op}")?;
                 val.limited_fmt(f, limit - 1)
             }
             Self::BinOp { op, lhs, rhs } => {
                 lhs.limited_fmt(f, limit - 1)?;
-                write!(f, " {} ", op)?;
+                write!(f, " {op} ")?;
                 rhs.limited_fmt(f, limit - 1)
             }
             Self::App { name, args } => {
-                write!(f, "{}", name)?;
+                write!(f, "{name}")?;
                 write!(f, "(")?;
                 for (i, arg) in args.iter().enumerate() {
                     if i > 0 {
@@ -270,10 +270,10 @@ impl LimitedDisplay for TyParam {
                 write!(f, "_: ")?;
                 t.limited_fmt(f, limit - 1)
             }
-            Self::Mono(name) => write!(f, "{}", name),
+            Self::Mono(name) => write!(f, "{name}"),
             Self::Proj { obj, attr } => {
-                write!(f, "{}.", obj)?;
-                write!(f, "{}", attr)
+                write!(f, "{obj}.")?;
+                write!(f, "{attr}")
             }
             Self::Array(arr) => {
                 write!(f, "[")?;
diff --git a/crates/erg_compiler/ty/value.rs b/crates/erg_compiler/ty/value.rs
index 33f9d9afd..c5357e486 100644
--- a/crates/erg_compiler/ty/value.rs
+++ b/crates/erg_compiler/ty/value.rs
@@ -455,7 +455,7 @@ impl fmt::Debug for ValueObj {
                     if i != 0 {
                         write!(f, ", ")?;
                     }
-                    write!(f, "{}: {}", k, v)?;
+                    write!(f, "{k}: {v}")?;
                 }
                 write!(f, "}}")
             }
@@ -977,7 +977,7 @@ impl ValueObj {
             (Self::Int(l), Self::Float(r)) => Some(Self::Float(l as f64 - r)),
             (Self::Nat(l), Self::Float(r)) => Some(Self::Float(l as f64 - r)),
             (Self::Float(l), Self::Int(r)) => Some(Self::Float(l - r as f64)),
-            (Self::Str(l), Self::Str(r)) => Some(Self::Str(Str::from(format!("{}{}", l, r)))),
+            (Self::Str(l), Self::Str(r)) => Some(Self::Str(Str::from(format!("{l}{r}")))),
             (inf @ (Self::Inf | Self::NegInf), _) | (_, inf @ (Self::Inf | Self::NegInf)) => {
                 Some(inf)
             }
diff --git a/crates/erg_parser/ast.rs b/crates/erg_parser/ast.rs
index a9d068a11..9b283355d 100644
--- a/crates/erg_parser/ast.rs
+++ b/crates/erg_parser/ast.rs
@@ -553,7 +553,7 @@ impl NestedDisplay for ArrayComprehension {
     fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
         let mut generators = String::new();
         for (name, gen) in self.generators.iter() {
-            write!(generators, "{} <- {}, ", name, gen).unwrap();
+            write!(generators, "{name} <- {gen}, ")?;
         }
         write!(
             f,
@@ -890,7 +890,7 @@ impl NestedDisplay for MixedRecord {
     fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
         write!(f, "{{")?;
         for attr in self.attrs.iter() {
-            write!(f, "{}; ", attr)?;
+            write!(f, "{attr}; ")?;
         }
         write!(f, "}}")
     }
@@ -1063,7 +1063,7 @@ impl NestedDisplay for Call {
             write!(f, "{}", self.obj)?;
         }
         if let Some(attr_name) = self.attr_name.as_ref() {
-            write!(f, "{}", attr_name)?;
+            write!(f, "{attr_name}")?;
         }
         if self.args.is_empty() {
             write!(f, "()")
@@ -2654,11 +2654,11 @@ impl NestedDisplay for VarPattern {
     fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
         match self {
             Self::Discard(_) => write!(f, "_"),
-            Self::Ident(ident) => write!(f, "{}", ident),
-            Self::Array(a) => write!(f, "{}", a),
-            Self::Tuple(t) => write!(f, "{}", t),
-            Self::Record(r) => write!(f, "{}", r),
-            Self::DataPack(d) => write!(f, "{}", d),
+            Self::Ident(ident) => write!(f, "{ident}"),
+            Self::Array(a) => write!(f, "{a}"),
+            Self::Tuple(t) => write!(f, "{t}"),
+            Self::Record(r) => write!(f, "{r}"),
+            Self::DataPack(d) => write!(f, "{d}"),
         }
     }
 }
@@ -2921,14 +2921,14 @@ pub enum ParamPattern {
 impl NestedDisplay for ParamPattern {
     fn fmt_nest(&self, f: &mut fmt::Formatter<'_>, _level: usize) -> fmt::Result {
         match self {
-            Self::Discard(tok) => write!(f, "{}", tok),
-            Self::VarName(var_name) => write!(f, "{}", var_name),
-            Self::Lit(lit) => write!(f, "{}", lit),
-            Self::Array(array) => write!(f, "{}", array),
-            Self::Tuple(tuple) => write!(f, "{}", tuple),
-            Self::Record(record) => write!(f, "{}", record),
-            Self::Ref(var_name) => write!(f, "ref {}", var_name),
-            Self::RefMut(var_name) => write!(f, "ref! {}", var_name),
+            Self::Discard(tok) => write!(f, "{tok}"),
+            Self::VarName(var_name) => write!(f, "{var_name}"),
+            Self::Lit(lit) => write!(f, "{lit}"),
+            Self::Array(array) => write!(f, "{array}"),
+            Self::Tuple(tuple) => write!(f, "{tuple}"),
+            Self::Record(record) => write!(f, "{record}"),
+            Self::Ref(var_name) => write!(f, "ref {var_name}"),
+            Self::RefMut(var_name) => write!(f, "ref! {var_name}"),
         }
     }
 }
diff --git a/crates/erg_parser/error.rs b/crates/erg_parser/error.rs
index 5c68eeaa9..6eb31f02f 100644
--- a/crates/erg_parser/error.rs
+++ b/crates/erg_parser/error.rs
@@ -239,22 +239,22 @@ impl LexError {
         let expect = switch_lang!(
                 "japanese" => {
                     expect.push_str("期待された構文: ");
-                    expect.push_str_with_color(&format!("!{}", lit), HINT);
+                    expect.push_str_with_color(&format!("!{lit}"), HINT);
                     expect
                 },
                 "simplified_chinese" => {
                     expect.push_str("预期语法: ");
-                    expect.push_str_with_color(&format!("!{}", lit), HINT);
+                    expect.push_str_with_color(&format!("!{lit}"), HINT);
                     expect
                 },
                 "traditional_chinese" => {
                     expect.push_str("預期語法: ");
-                    expect.push_str_with_color(&format!("!{}", lit), HINT);
+                    expect.push_str_with_color(&format!("!{lit}"), HINT);
                     expect
                 },
                 "english" => {
                     expect.push_str("expected: ");
-                    expect.push_str_with_color(&format!("!{}", lit), HINT);
+                    expect.push_str_with_color(&format!("!{lit}"), HINT);
                     expect
                 },
         )
@@ -263,22 +263,22 @@ impl LexError {
         let found = switch_lang!(
                 "japanese" => {
                     found.push_str("見つかった構文: ");
-                    found.push_str_with_color(&format!("{}!", lit), ERR);
+                    found.push_str_with_color(&format!("{lit}!"), ERR);
                     found
                 },
                 "simplified_chinese" => {
                     found.push_str("找到语法: ");
-                    found.push_str_with_color(&format!("{}!", lit), ERR);
+                    found.push_str_with_color(&format!("{lit}!"), ERR);
                     found
                 },
                 "traditional_chinese" => {
                     found.push_str("找到語法: ");
-                    found.push_str_with_color(&format!("{}!", lit), ERR);
+                    found.push_str_with_color(&format!("{lit}!"), ERR);
                     found
                 },
                 "english" => {
                     found.push_str("but found: ");
-                    found.push_str_with_color(&format!("{}!", lit), ERR);
+                    found.push_str_with_color(&format!("{lit}!"), ERR);
                     found
                 },
         )
diff --git a/crates/erg_parser/lex.rs b/crates/erg_parser/lex.rs
index 19e61ee49..26e76072d 100644
--- a/crates/erg_parser/lex.rs
+++ b/crates/erg_parser/lex.rs
@@ -393,10 +393,10 @@ impl Lexer /*<'a>*/ {
         }
         let comment = self.emit_token(Illegal, &s);
         let hint = switch_lang!(
-            "japanese" => format!("`]#`の数があと{}個必要です", nest_level),
-            "simplified_chinese" => format!("需要{}个`]#`", nest_level),
-            "traditional_chinese" => format!("需要{}個`]#`", nest_level),
-            "english" => format!("{} `]#`(s) are needed", nest_level),
+            "japanese" => format!("`]#`の数があと{nest_level}個必要です"),
+            "simplified_chinese" => format!("需要{nest_level}个`]#`"),
+            "traditional_chinese" => format!("需要{nest_level}個`]#`"),
+            "english" => format!("{nest_level} `]#`(s) are needed"),
         );
         Err(LexError::syntax_error(
             line!() as usize,
@@ -731,10 +731,10 @@ impl Lexer /*<'a>*/ {
             line!() as usize,
             token.loc(),
             switch_lang!(
-                "japanese" => format!("不正なエスケープシーケンスです: \\{}", ch),
-                "simplified_chinese" => format!("不合法的转义序列: \\{}", ch),
-                "traditional_chinese" => format!("不合法的轉義序列: \\{}", ch),
-                "english" => format!("illegal escape sequence: \\{}", ch),
+                "japanese" => format!("不正なエスケープシーケンスです: \\{ch}"),
+                "simplified_chinese" => format!("不合法的转义序列: \\{ch}"),
+                "traditional_chinese" => format!("不合法的轉義序列: \\{ch}"),
+                "english" => format!("illegal escape sequence: \\{ch}"),
             ),
             None,
         )