Fix clippy::single_char_pattern

crates/ra_assists/src/introduce_variable.rs

@@ -57,9 +57,9 @@ pub(crate) fn introduce_variable(mut ctx: AssistCtx<impl HirDatabase>) -> Option
             if text.starts_with("\r\n") {
                 buf.push_str("\r\n");
                 buf.push_str(text.trim_start_matches("\r\n"));
-            } else if text.starts_with("\n") {
+            } else if text.starts_with('\n') {
                 buf.push_str("\n");
-                buf.push_str(text.trim_start_matches("\n"));
+                buf.push_str(text.trim_start_matches('\n'));
             } else {
                 buf.push_str(text);
             }

crates/ra_hir/src/expr/validation.rs

@@ -31,11 +31,8 @@ impl<'a, 'b> ExprValidator<'a, 'b> {
     pub(crate) fn validate_body(&mut self, db: &impl HirDatabase) {
         let body = self.func.body(db);
         for e in body.exprs() {
-            match e {
+            if let (id, Expr::StructLit { path, fields, spread }) = e {
-                (id, Expr::StructLit { path, fields, spread }) => {
+                self.validate_struct_literal(id, path, fields, spread, db);
-                    self.validate_struct_literal(id, path, fields, spread, db)
-                }
-                _ => (),
             }
         }
     }

crates/ra_project_model/src/lib.rs

@@ -70,7 +70,7 @@ impl ProjectRoot {
             })
         };
 
-        let hidden = dir_path.components().any(|c| c.as_str().starts_with("."));
+        let hidden = dir_path.components().any(|c| c.as_str().starts_with('.'));
 
         !is_ignored && !hidden
     }

crates/ra_syntax/src/ast/extensions.rs

@@ -78,7 +78,7 @@ impl ast::Attr {
         if attr.kind() == IDENT {
             let key = attr.as_token()?.text().clone();
             let val_node = tt_node.children_with_tokens().find(|t| t.kind() == STRING)?;
-            let val = val_node.as_token()?.text().trim_start_matches("\"").trim_end_matches("\"");
+            let val = val_node.as_token()?.text().trim_start_matches('"').trim_end_matches('"');
             Some((key, SmolStr::new(val)))
         } else {
             None