Simplify

crates/ide_assists/src/handlers/extract_function.rs

@@ -100,7 +100,7 @@ pub(crate) fn extract_function(acc: &mut Assists, ctx: &AssistContext) -> Option
                 body.extracted_function_params(ctx, &container_info, locals_used.iter().copied());
 
             let fun = Function {
-                name: "fun_name".to_string(),
+                name: make::name_ref("fun_name"),
                 self_param,
                 params,
                 control_flow,
@@ -170,7 +170,7 @@ fn extraction_target(node: &SyntaxNode, selection_range: TextRange) -> Option<Fu
 
 #[derive(Debug)]
 struct Function {
-    name: String,
+    name: ast::NameRef,
     self_param: Option<ast::SelfParam>,
     params: Vec<Param>,
     control_flow: ControlFlow,
@@ -1077,11 +1077,12 @@ fn make_call(ctx: &AssistContext, fun: &Function, indent: IndentLevel) -> String
 
     let args = fun.params.iter().map(|param| param.to_arg(ctx));
     let args = make::arg_list(args);
+    let name = fun.name.clone();
     let call_expr = if fun.self_param.is_some() {
         let self_arg = make::expr_path(make::ext::ident_path("self"));
-        make::expr_method_call(self_arg, &fun.name, args)
+        make::expr_method_call(self_arg, name, args)
     } else {
-        let func = make::expr_path(make::ext::ident_path(&fun.name));
+        let func = make::expr_path(make::path_unqualified(make::path_segment(name)));
         make::expr_call(func, args)
     };
 

crates/ide_assists/src/handlers/invert_if.rs

@@ -35,7 +35,7 @@ pub(crate) fn invert_if(acc: &mut Assists, ctx: &AssistContext) -> Option<()> {
     }
 
     // This assist should not apply for if-let.
-    if expr.condition()?.pat().is_some() {
+    if expr.condition()?.is_pattern_cond() {
         return None;
     }
 

crates/ide_assists/src/handlers/move_guard.rs

@@ -115,7 +115,7 @@ pub(crate) fn move_arm_cond_to_match_guard(acc: &mut Assists, ctx: &AssistContex
         return None;
     }
     // Not support moving if let to arm guard
-    if cond.pat().is_some() {
+    if cond.is_pattern_cond() {
         return None;
     }
 

crates/ide_assists/src/utils.rs

@@ -248,7 +248,7 @@ fn invert_special_case(sema: &Semantics<RootDatabase>, expr: &ast::Expr) -> Opti
                 "is_err" => "is_ok",
                 _ => return None,
             };
-            Some(make::expr_method_call(receiver, method, arg_list))
+            Some(make::expr_method_call(receiver, make::name_ref(method), arg_list))
         }
         ast::Expr::PrefixExpr(pe) if pe.op_kind()? == ast::PrefixOp::Not => {
             if let ast::Expr::ParenExpr(parexpr) = pe.expr()? {

crates/ide_diagnostics/src/handlers/unlinked_file.rs

@@ -38,7 +38,7 @@ fn fixes(ctx: &DiagnosticsContext, file_id: FileId) -> Option<Vec<Assist>> {
 
     let source_root = ctx.sema.db.source_root(ctx.sema.db.file_source_root(file_id));
     let our_path = source_root.path_for_file(&file_id)?;
-    let module_name = our_path.name_and_extension()?.0;
+    let (module_name, _) = our_path.name_and_extension()?;
 
     // Candidates to look for:
     // - `mod.rs` in the same folder
@@ -48,26 +48,23 @@ fn fixes(ctx: &DiagnosticsContext, file_id: FileId) -> Option<Vec<Assist>> {
     let mut paths = vec![parent.join("mod.rs")?, parent.join("lib.rs")?, parent.join("main.rs")?];
 
     // `submod/bla.rs` -> `submod.rs`
-    if let Some(newmod) = (|| {
-        let name = parent.name_and_extension()?.0;
+    let parent_mod = (|| {
+        let (name, _) = parent.name_and_extension()?;
         parent.parent()?.join(&format!("{}.rs", name))
-    })() {
-        paths.push(newmod);
-    }
+    })();
+    paths.extend(parent_mod);
 
-    for path in &paths {
-        if let Some(parent_id) = source_root.file_for_path(path) {
-            for krate in ctx.sema.db.relevant_crates(*parent_id).iter() {
-                let crate_def_map = ctx.sema.db.crate_def_map(*krate);
+    for &parent_id in paths.iter().filter_map(|path| source_root.file_for_path(path)) {
+        for &krate in ctx.sema.db.relevant_crates(parent_id).iter() {
+            let crate_def_map = ctx.sema.db.crate_def_map(krate);
             for (_, module) in crate_def_map.modules() {
                 if module.origin.is_inline() {
                     // We don't handle inline `mod parent {}`s, they use different paths.
                     continue;
                 }
 
-                    if module.origin.file_id() == Some(*parent_id) {
-                        return make_fixes(ctx.sema.db, *parent_id, module_name, file_id);
-                    }
+                if module.origin.file_id() == Some(parent_id) {
+                    return make_fixes(ctx.sema.db, parent_id, module_name, file_id);
                 }
             }
         }

crates/syntax/src/ast/expr_ext.rs

@@ -48,7 +48,7 @@ impl ast::Expr {
     }
 
     /// Preorder walk all the expression's child expressions preserving events.
-    /// If the callback returns true the subtree of the expression will be skipped.
+    /// If the callback returns true on an [`WalkEvent::Enter`], the subtree of the expression will be skipped.
     /// Note that the subtree may already be skipped due to the context analysis this function does.
     pub fn preorder(&self, cb: &mut dyn FnMut(WalkEvent<ast::Expr>) -> bool) {
         let mut preorder = self.syntax().preorder();

crates/syntax/src/ast/make.rs

@@ -304,12 +304,20 @@ pub fn expr_prefix(op: SyntaxKind, expr: ast::Expr) -> ast::Expr {
 pub fn expr_call(f: ast::Expr, arg_list: ast::ArgList) -> ast::Expr {
     expr_from_text(&format!("{}{}", f, arg_list))
 }
-pub fn expr_method_call(receiver: ast::Expr, method: &str, arg_list: ast::ArgList) -> ast::Expr {
+pub fn expr_method_call(
+    receiver: ast::Expr,
+    method: ast::NameRef,
+    arg_list: ast::ArgList,
+) -> ast::Expr {
     expr_from_text(&format!("{}.{}{}", receiver, method, arg_list))
 }
 pub fn expr_ref(expr: ast::Expr, exclusive: bool) -> ast::Expr {
     expr_from_text(&if exclusive { format!("&mut {}", expr) } else { format!("&{}", expr) })
 }
+pub fn expr_closure(pats: impl IntoIterator<Item = ast::Param>, expr: ast::Expr) -> ast::Expr {
+    let params = pats.into_iter().join(", ");
+    expr_from_text(&format!("|{}| {}", params, expr))
+}
 pub fn expr_paren(expr: ast::Expr) -> ast::Expr {
     expr_from_text(&format!("({})", expr))
 }

crates/syntax/src/ast/node_ext.rs

@@ -611,6 +611,12 @@ impl ast::Item {
     }
 }
 
+impl ast::Condition {
+    pub fn is_pattern_cond(&self) -> bool {
+        self.let_token().is_some()
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub enum FieldKind {
     Name(ast::NameRef),