refactor: fix clippy warnings (#19)

.devcontainer/devcontainer.json

@@ -1,12 +1,14 @@
 {
-  "name": "Rust",
-  "image": "mcr.microsoft.com/devcontainers/rust:1-bullseye",
-  "customizations": {
-    "vscode": {
-      "extensions": [
-        "EditorConfig.EditorConfig"
-      ],
-      "settings": {}
+    "name": "Rust",
+    "image": "mcr.microsoft.com/devcontainers/rust:bullseye",
+    "customizations": {
+        "vscode": {
+            "extensions": [
+                "EditorConfig.EditorConfig"
+            ],
+            "settings": {
+                "rust-analyzer.checkOnSave.command": "clippy"
+            }
+        }
     }
-  }
 }

src/process/writer.rs

@@ -29,7 +29,7 @@ impl<W: Write> GuiCommandWriter<W> {
     }
 
     pub fn send(&mut self, command: &GuiCommand) -> Result<(), Error> {
-        let s = format!("{}\n", command);
+        let s = format!("{command}\n");
         self.writer.write_all(s.as_bytes())?;
         self.writer.flush()?;
 

src/protocol/command.rs

@@ -176,11 +176,11 @@ mod tests {
         ];
 
         for (i, c) in ok_cases.iter().enumerate() {
-            assert!(EngineCommand::parse(c).is_ok(), "failed at #{}", i);
+            assert!(EngineCommand::parse(c).is_ok(), "failed at #{i}");
         }
 
         for (i, c) in ng_cases.iter().enumerate() {
-            assert!(EngineCommand::parse(c).is_err(), "failed at #{}", i);
+            assert!(EngineCommand::parse(c).is_err(), "failed at #{i}");
         }
     }
 }

src/protocol/gui.rs

@@ -156,14 +156,14 @@ pub enum GuiCommand {
 impl fmt::Display for GuiCommand {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
         match *self {
-            GuiCommand::GameOver(ref r) => write!(f, "gameover {}", r),
-            GuiCommand::Go(ref opt) => write!(f, "go{}", opt),
+            GuiCommand::GameOver(ref r) => write!(f, "gameover {r}"),
+            GuiCommand::Go(ref opt) => write!(f, "go{opt}"),
             GuiCommand::IsReady => write!(f, "isready"),
             GuiCommand::Ponderhit => write!(f, "ponderhit"),
-            GuiCommand::Position(ref s) => write!(f, "position sfen {}", s),
-            GuiCommand::SetOption(ref n, None) => write!(f, "setoption name {}", n),
+            GuiCommand::Position(ref s) => write!(f, "position sfen {s}"),
+            GuiCommand::SetOption(ref n, None) => write!(f, "setoption name {n}"),
             GuiCommand::SetOption(ref n, Some(ref v)) => {
-                write!(f, "setoption name {} value {}", n, v)
+                write!(f, "setoption name {n} value {v}")
             }
             GuiCommand::Stop => write!(f, "stop"),
             GuiCommand::Usi => write!(f, "usi"),