More manual clippy fixes

crates/ra_ide/src/call_info.rs

@@ -128,7 +128,7 @@ impl FnCallNode {
             }),
 
             FnCallNode::MethodCallExpr(call_expr) => {
-                call_expr.syntax().children().filter_map(ast::NameRef::cast).nth(0)
+                call_expr.syntax().children().filter_map(ast::NameRef::cast).next()
             }
 
             FnCallNode::MacroCallExpr(call_expr) => call_expr.path()?.segment()?.name_ref(),

crates/ra_ide/src/completion/complete_trait_impl.rs

@@ -59,7 +59,7 @@ pub(crate) fn complete_trait_impl(acc: &mut Completions, ctx: &CompletionContext
         .as_ref()
         .and_then(|node| node.parent())
         .and_then(|node| node.parent())
-        .and_then(|node| ast::ImplBlock::cast(node));
+        .and_then(ast::ImplBlock::cast);
 
     if let (Some(trigger), Some(impl_block)) = (trigger, impl_block) {
         match trigger.kind() {
@@ -110,17 +110,17 @@ fn add_function_impl(
     ctx: &CompletionContext,
     func: &hir::Function,
 ) {
-    let display = FunctionSignature::from_hir(ctx.db, func.clone());
+    let display = FunctionSignature::from_hir(ctx.db, *func);
 
     let fn_name = func.name(ctx.db).to_string();
 
-    let label = if func.params(ctx.db).len() > 0 {
+    let label = if !func.params(ctx.db).is_empty() {
         format!("fn {}(..)", fn_name)
     } else {
         format!("fn {}()", fn_name)
     };
 
-    let builder = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label.clone())
+    let builder = CompletionItem::new(CompletionKind::Magic, ctx.source_range(), label)
         .lookup_by(fn_name)
         .set_documentation(func.docs(ctx.db));
 

crates/ra_ide/src/completion/completion_item.rs

@@ -159,7 +159,7 @@ impl CompletionItem {
 
     /// Short one-line additional information, like a type
     pub fn detail(&self) -> Option<&str> {
-        self.detail.as_ref().map(|it| it.as_str())
+        self.detail.as_deref()
     }
     /// A doc-comment
     pub fn documentation(&self) -> Option<Documentation> {
@@ -167,7 +167,7 @@ impl CompletionItem {
     }
     /// What string is used for filtering.
     pub fn lookup(&self) -> &str {
-        self.lookup.as_ref().map(|it| it.as_str()).unwrap_or_else(|| self.label())
+        self.lookup.as_deref().unwrap_or_else(|| self.label())
     }
 
     pub fn kind(&self) -> Option<CompletionItemKind> {

crates/ra_ide/src/display/function_signature.rs

@@ -54,9 +54,8 @@ impl FunctionSignature {
 
     pub(crate) fn from_struct(db: &RootDatabase, st: hir::Struct) -> Option<Self> {
         let node: ast::StructDef = st.source(db).value;
-        match node.kind() {
-            ast::StructKind::Record(_) => return None,
-            _ => (),
+        if let ast::StructKind::Record(_) = node.kind() {
+            return None;
         };
 
         let params = st

crates/ra_ide/src/display/navigation_target.rs

@@ -64,11 +64,11 @@ impl NavigationTarget {
     }
 
     pub fn docs(&self) -> Option<&str> {
-        self.docs.as_ref().map(String::as_str)
+        self.docs.as_deref()
     }
 
     pub fn description(&self) -> Option<&str> {
-        self.description.as_ref().map(String::as_str)
+        self.description.as_deref()
     }
 
     /// A "most interesting" range withing the `full_range`.

crates/ra_ide/src/references.rs

@@ -268,7 +268,7 @@ fn decl_access(
     };
 
     let stmt = find_node_at_offset::<ast::LetStmt>(syntax, range.start())?;
-    if let Some(_) = stmt.initializer() {
+    if stmt.initializer().is_some() {
         let pat = stmt.pat()?;
         if let ast::Pat::BindPat(it) = pat {
             if it.name()?.text().as_str() == name {

crates/ra_ide/src/ssr.rs

@@ -85,8 +85,11 @@ impl FromStr for SsrQuery {
     fn from_str(query: &str) -> Result<SsrQuery, SsrError> {
         let mut it = query.split("==>>");
         let pattern = it.next().expect("at least empty string").trim();
-        let mut template =
-            it.next().ok_or(SsrError("Cannot find delemiter `==>>`".into()))?.trim().to_string();
+        let mut template = it
+            .next()
+            .ok_or_else(|| SsrError("Cannot find delemiter `==>>`".into()))?
+            .trim()
+            .to_string();
         if it.next().is_some() {
             return Err(SsrError("More than one delimiter found".into()));
         }
@@ -131,11 +134,12 @@ fn traverse(node: &SyntaxNode, go: &mut impl FnMut(&SyntaxNode) -> bool) {
 }
 
 fn split_by_var(s: &str) -> Result<(&str, &str, &str), SsrError> {
-    let end_of_name = s.find(":").ok_or(SsrError("Use $<name>:expr".into()))?;
+    let end_of_name = s.find(':').ok_or_else(|| SsrError("Use $<name>:expr".into()))?;
     let name = &s[0..end_of_name];
     is_name(name)?;
     let type_begin = end_of_name + 1;
-    let type_length = s[type_begin..].find(|c| !char::is_ascii_alphanumeric(&c)).unwrap_or(s.len());
+    let type_length =
+        s[type_begin..].find(|c| !char::is_ascii_alphanumeric(&c)).unwrap_or_else(|| s.len());
     let type_name = &s[type_begin..type_begin + type_length];
     Ok((name, type_name, &s[type_begin + type_length..]))
 }
@@ -182,7 +186,7 @@ fn find(pattern: &SsrPattern, code: &SyntaxNode) -> SsrMatches {
                 pattern.text() == code.text()
             }
             (SyntaxElement::Node(ref pattern), SyntaxElement::Node(ref code)) => {
-                if placeholders.iter().find(|&n| n.0.as_str() == pattern.text()).is_some() {
+                if placeholders.iter().any(|n| n.0.as_str() == pattern.text()) {
                     match_.binding.insert(Var(pattern.text().to_string()), code.clone());
                     true
                 } else {