18 files changed, 136 insertions, 192 deletions

diff --git a/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs b/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs
index b5b5ada5e..70949ca35 100644
--- a/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs
+++ b/crates/ide_assists/src/handlers/convert_tuple_struct_to_named_struct.rs
@@ -107,7 +107,7 @@ fn edit_struct_references(
     names: &[ast::Name],
 ) {
     let strukt_def = Definition::ModuleDef(hir::ModuleDef::Adt(hir::Adt::Struct(strukt)));
-    let usages = strukt_def.usages(&ctx.sema).include_self_kw_refs(true).all();
+    let usages = strukt_def.usages(&ctx.sema).include_self_refs().all();
 
     let edit_node = |edit: &mut AssistBuilder, node: SyntaxNode| -> Option<()> {
         match_ast! {
diff --git a/crates/ide_assists/src/handlers/early_return.rs b/crates/ide_assists/src/handlers/early_return.rs
index c66f8c05d..5eb6a57f0 100644
--- a/crates/ide_assists/src/handlers/early_return.rs
+++ b/crates/ide_assists/src/handlers/early_return.rs
@@ -130,9 +130,7 @@ pub(crate) fn convert_to_guarded_return(acc: &mut Assists, ctx: &AssistContext)
                                 once(make::ident_pat(make::name("it")).into()),
                             );
                             let expr = {
-                                let name_ref = make::name_ref("it");
-                                let segment = make::path_segment(name_ref);
-                                let path = make::path_unqualified(segment);
+                                let path = make::ext::ident_path("it");
                                 make::expr_path(path)
                             };
                             make::match_arm(once(pat.into()), expr)
diff --git a/crates/ide_assists/src/handlers/expand_glob_import.rs b/crates/ide_assists/src/handlers/expand_glob_import.rs
index e3095f26b..da8d245e5 100644
--- a/crates/ide_assists/src/handlers/expand_glob_import.rs
+++ b/crates/ide_assists/src/handlers/expand_glob_import.rs
@@ -65,8 +65,7 @@ pub(crate) fn expand_glob_import(acc: &mut Assists, ctx: &AssistContext) -> Opti
 
             let names_to_import = find_names_to_import(ctx, refs_in_target, imported_defs);
             let expanded = make::use_tree_list(names_to_import.iter().map(|n| {
-                let path =
-                    make::path_unqualified(make::path_segment(make::name_ref(&n.to_string())));
+                let path = make::ext::ident_path(&n.to_string());
                 make::use_tree(path, None, None, false)
             }))
             .clone_for_update();
diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index 4116985ae..6311afc1f 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -956,10 +956,10 @@ fn format_replacement(ctx: &AssistContext, fun: &Function, indent: IndentLevel)
     let args = fun.params.iter().map(|param| param.to_arg(ctx));
     let args = make::arg_list(args);
     let call_expr = if fun.self_param.is_some() {
-        let self_arg = make::expr_path(make_path_from_text("self"));
+        let self_arg = make::expr_path(make::ext::ident_path("self"));
         make::expr_method_call(self_arg, &fun.name, args)
     } else {
-        let func = make::expr_path(make_path_from_text(&fun.name));
+        let func = make::expr_path(make::ext::ident_path(&fun.name));
         make::expr_call(func, args)
     };
 
@@ -1054,11 +1054,11 @@ impl FlowHandler {
                 make::expr_if(condition, block, None)
             }
             FlowHandler::IfOption { action } => {
-                let path = make_path_from_text("Some");
+                let path = make::ext::ident_path("Some");
                 let value_pat = make::ident_pat(make::name("value"));
                 let pattern = make::tuple_struct_pat(path, iter::once(value_pat.into()));
                 let cond = make::condition(call_expr, Some(pattern.into()));
-                let value = make::expr_path(make_path_from_text("value"));
+                let value = make::expr_path(make::ext::ident_path("value"));
                 let action_expr = action.make_result_handler(Some(value));
                 let action_stmt = make::expr_stmt(action_expr);
                 let then = make::block_expr(iter::once(action_stmt.into()), None);
@@ -1068,14 +1068,14 @@ impl FlowHandler {
                 let some_name = "value";
 
                 let some_arm = {
-                    let path = make_path_from_text("Some");
+                    let path = make::ext::ident_path("Some");
                     let value_pat = make::ident_pat(make::name(some_name));
                     let pat = make::tuple_struct_pat(path, iter::once(value_pat.into()));
-                    let value = make::expr_path(make_path_from_text(some_name));
+                    let value = make::expr_path(make::ext::ident_path(some_name));
                     make::match_arm(iter::once(pat.into()), value)
                 };
                 let none_arm = {
-                    let path = make_path_from_text("None");
+                    let path = make::ext::ident_path("None");
                     let pat = make::path_pat(path);
                     make::match_arm(iter::once(pat), none.make_result_handler(None))
                 };
@@ -1087,17 +1087,17 @@ impl FlowHandler {
                 let err_name = "value";
 
                 let ok_arm = {
-                    let path = make_path_from_text("Ok");
+                    let path = make::ext::ident_path("Ok");
                     let value_pat = make::ident_pat(make::name(ok_name));
                     let pat = make::tuple_struct_pat(path, iter::once(value_pat.into()));
-                    let value = make::expr_path(make_path_from_text(ok_name));
+                    let value = make::expr_path(make::ext::ident_path(ok_name));
                     make::match_arm(iter::once(pat.into()), value)
                 };
                 let err_arm = {
-                    let path = make_path_from_text("Err");
+                    let path = make::ext::ident_path("Err");
                     let value_pat = make::ident_pat(make::name(err_name));
                     let pat = make::tuple_struct_pat(path, iter::once(value_pat.into()));
-                    let value = make::expr_path(make_path_from_text(err_name));
+                    let value = make::expr_path(make::ext::ident_path(err_name));
                     make::match_arm(iter::once(pat.into()), err.make_result_handler(Some(value)))
                 };
                 let arms = make::match_arm_list(vec![ok_arm, err_arm]);
@@ -1107,13 +1107,9 @@ impl FlowHandler {
     }
 }
 
-fn make_path_from_text(text: &str) -> ast::Path {
-    make::path_unqualified(make::path_segment(make::name_ref(text)))
-}
-
 fn path_expr_from_local(ctx: &AssistContext, var: Local) -> ast::Expr {
     let name = var.name(ctx.db()).unwrap().to_string();
-    make::expr_path(make_path_from_text(&name))
+    make::expr_path(make::ext::ident_path(&name))
 }
 
 fn format_function(
@@ -1179,7 +1175,7 @@ fn make_ret_ty(ctx: &AssistContext, module: hir::Module, fun: &Function) -> Opti
             fun_ty.make_ty(ctx, module)
         }
         FlowHandler::Try { kind: TryKind::Option } => {
-            make::ty_generic(make::name_ref("Option"), iter::once(fun_ty.make_ty(ctx, module)))
+            make::ext::ty_option(fun_ty.make_ty(ctx, module))
         }
         FlowHandler::Try { kind: TryKind::Result { ty: parent_ret_ty } } => {
             let handler_ty = parent_ret_ty
@@ -1187,29 +1183,21 @@ fn make_ret_ty(ctx: &AssistContext, module: hir::Module, fun: &Function) -> Opti
                 .nth(1)
                 .map(|ty| make_ty(&ty, ctx, module))
                 .unwrap_or_else(make::ty_unit);
-            make::ty_generic(
-                make::name_ref("Result"),
-                vec![fun_ty.make_ty(ctx, module), handler_ty],
-            )
+            make::ext::ty_result(fun_ty.make_ty(ctx, module), handler_ty)
         }
-        FlowHandler::If { .. } => make::ty("bool"),
+        FlowHandler::If { .. } => make::ext::ty_bool(),
         FlowHandler::IfOption { action } => {
             let handler_ty = action
                 .expr_ty(ctx)
                 .map(|ty| make_ty(&ty, ctx, module))
                 .unwrap_or_else(make::ty_unit);
-            make::ty_generic(make::name_ref("Option"), iter::once(handler_ty))
-        }
-        FlowHandler::MatchOption { .. } => {
-            make::ty_generic(make::name_ref("Option"), iter::once(fun_ty.make_ty(ctx, module)))
+            make::ext::ty_option(handler_ty)
         }
+        FlowHandler::MatchOption { .. } => make::ext::ty_option(fun_ty.make_ty(ctx, module)),
         FlowHandler::MatchResult { err } => {
             let handler_ty =
                 err.expr_ty(ctx).map(|ty| make_ty(&ty, ctx, module)).unwrap_or_else(make::ty_unit);
-            make::ty_generic(
-                make::name_ref("Result"),
-                vec![fun_ty.make_ty(ctx, module), handler_ty],
-            )
+            make::ext::ty_result(fun_ty.make_ty(ctx, module), handler_ty)
         }
     };
     Some(make::ret_type(ret_ty))
@@ -1296,7 +1284,7 @@ fn make_body(
                     TryKind::Option => "Some",
                     TryKind::Result { .. } => "Ok",
                 };
-                let func = make::expr_path(make_path_from_text(constructor));
+                let func = make::expr_path(make::ext::ident_path(constructor));
                 let args = make::arg_list(iter::once(tail_expr));
                 make::expr_call(func, args)
             })
@@ -1306,16 +1294,16 @@ fn make_body(
             with_tail_expr(block, lit_false.into())
         }
         FlowHandler::IfOption { .. } => {
-            let none = make::expr_path(make_path_from_text("None"));
+            let none = make::expr_path(make::ext::ident_path("None"));
             with_tail_expr(block, none)
         }
         FlowHandler::MatchOption { .. } => map_tail_expr(block, |tail_expr| {
-            let some = make::expr_path(make_path_from_text("Some"));
+            let some = make::expr_path(make::ext::ident_path("Some"));
             let args = make::arg_list(iter::once(tail_expr));
             make::expr_call(some, args)
         }),
         FlowHandler::MatchResult { .. } => map_tail_expr(block, |tail_expr| {
-            let ok = make::expr_path(make_path_from_text("Ok"));
+            let ok = make::expr_path(make::ext::ident_path("Ok"));
             let args = make::arg_list(iter::once(tail_expr));
             make::expr_call(ok, args)
         }),
@@ -1483,13 +1471,13 @@ fn make_rewritten_flow(handler: &FlowHandler, arg_expr: Option<ast::Expr>) -> Op
         FlowHandler::IfOption { .. } => {
             let expr = arg_expr.unwrap_or_else(|| make::expr_tuple(Vec::new()));
             let args = make::arg_list(iter::once(expr));
-            make::expr_call(make::expr_path(make_path_from_text("Some")), args)
+            make::expr_call(make::expr_path(make::ext::ident_path("Some")), args)
         }
-        FlowHandler::MatchOption { .. } => make::expr_path(make_path_from_text("None")),
+        FlowHandler::MatchOption { .. } => make::expr_path(make::ext::ident_path("None")),
         FlowHandler::MatchResult { .. } => {
             let expr = arg_expr.unwrap_or_else(|| make::expr_tuple(Vec::new()));
             let args = make::arg_list(iter::once(expr));
-            make::expr_call(make::expr_path(make_path_from_text("Err")), args)
+            make::expr_call(make::expr_path(make::ext::ident_path("Err")), args)
         }
     };
     Some(make::expr_return(Some(value)).clone_for_update())
diff --git a/crates/ide_assists/src/handlers/extract_variable.rs b/crates/ide_assists/src/handlers/extract_variable.rs
index 136b9a55b..ae084c86c 100644
--- a/crates/ide_assists/src/handlers/extract_variable.rs
+++ b/crates/ide_assists/src/handlers/extract_variable.rs
@@ -54,7 +54,7 @@ pub(crate) fn extract_variable(acc: &mut Assists, ctx: &AssistContext) -> Option
 
             let var_name = match &field_shorthand {
                 Some(it) => it.to_string(),
-                None => suggest_name::variable(&to_extract, &ctx.sema),
+                None => suggest_name::for_variable(&to_extract, &ctx.sema),
             };
             let expr_range = match &field_shorthand {
                 Some(it) => it.syntax().text_range().cover(to_extract.syntax().text_range()),
diff --git a/crates/ide_assists/src/handlers/generate_function.rs b/crates/ide_assists/src/handlers/generate_function.rs
index 6f95b1a07..bc9fc524b 100644
--- a/crates/ide_assists/src/handlers/generate_function.rs
+++ b/crates/ide_assists/src/handlers/generate_function.rs
@@ -175,7 +175,7 @@ impl FunctionBuilder {
     }
 
     fn render(self) -> FunctionTemplate {
-        let placeholder_expr = make::expr_todo();
+        let placeholder_expr = make::ext::expr_todo();
         let fn_body = make::block_expr(vec![], Some(placeholder_expr));
         let visibility = if self.needs_pub { Some(make::visibility_pub_crate()) } else { None };
         let mut fn_def = make::fn_(
diff --git a/crates/ide_assists/src/handlers/introduce_named_lifetime.rs b/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
index 9f4f71d6c..68bc15120 100644
--- a/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
+++ b/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
@@ -89,14 +89,12 @@ fn generate_fn_def_assist(
         let loc_needing_lifetime =
             loc_needing_lifetime.and_then(|it| it.make_mut(builder).to_position());
 
-        add_lifetime_param(fn_def.get_or_create_generic_param_list(), new_lifetime_param);
-        ted::replace(
-            lifetime.syntax(),
-            make_ast_lifetime(new_lifetime_param).clone_for_update().syntax(),
+        fn_def.get_or_create_generic_param_list().add_generic_param(
+            make::lifetime_param(new_lifetime_param.clone()).clone_for_update().into(),
         );
-        loc_needing_lifetime.map(|position| {
-            ted::insert(position, make_ast_lifetime(new_lifetime_param).clone_for_update().syntax())
-        });
+        ted::replace(lifetime.syntax(), new_lifetime_param.clone_for_update().syntax());
+        loc_needing_lifetime
+            .map(|position| ted::insert(position, new_lifetime_param.clone_for_update().syntax()));
     })
 }
 
@@ -112,11 +110,10 @@ fn generate_impl_def_assist(
         let impl_def = builder.make_ast_mut(impl_def);
         let lifetime = builder.make_ast_mut(lifetime);
 
-        add_lifetime_param(impl_def.get_or_create_generic_param_list(), new_lifetime_param);
-        ted::replace(
-            lifetime.syntax(),
-            make_ast_lifetime(new_lifetime_param).clone_for_update().syntax(),
+        impl_def.get_or_create_generic_param_list().add_generic_param(
+            make::lifetime_param(new_lifetime_param.clone()).clone_for_update().into(),
         );
+        ted::replace(lifetime.syntax(), new_lifetime_param.clone_for_update().syntax());
     })
 }
 
@@ -124,31 +121,16 @@ fn generate_impl_def_assist(
 /// which is not in the list
 fn generate_unique_lifetime_param_name(
     existing_type_param_list: Option<ast::GenericParamList>,
-) -> Option<char> {
+) -> Option<ast::Lifetime> {
     match existing_type_param_list {
         Some(type_params) => {
-            let used_lifetime_params: FxHashSet<_> = type_params
-                .lifetime_params()
-                .map(|p| p.syntax().text().to_string()[1..].to_owned())
-                .collect();
-            (b'a'..=b'z').map(char::from).find(|c| !used_lifetime_params.contains(&c.to_string()))
+            let used_lifetime_params: FxHashSet<_> =
+                type_params.lifetime_params().map(|p| p.syntax().text().to_string()).collect();
+            ('a'..='z').map(|it| format!("'{}", it)).find(|it| !used_lifetime_params.contains(it))
         }
-        None => Some('a'),
+        None => Some("'a".to_string()),
     }
-}
-
-fn add_lifetime_param(type_params: ast::GenericParamList, new_lifetime_param: char) {
-    let generic_param =
-        make::generic_param(format!("'{}", new_lifetime_param), None).clone_for_update();
-    type_params.add_generic_param(generic_param);
-}
-
-fn make_ast_lifetime(new_lifetime_param: char) -> ast::Lifetime {
-    make::generic_param(format!("'{}", new_lifetime_param), None)
-        .syntax()
-        .descendants()
-        .find_map(ast::Lifetime::cast)
-        .unwrap()
+    .map(|it| make::lifetime(&it))
 }
 
 enum NeedsLifetime {
diff --git a/crates/ide_assists/src/handlers/merge_imports.rs b/crates/ide_assists/src/handlers/merge_imports.rs
index add7b8e37..3cd090737 100644
--- a/crates/ide_assists/src/handlers/merge_imports.rs
+++ b/crates/ide_assists/src/handlers/merge_imports.rs
@@ -27,14 +27,14 @@ pub(crate) fn merge_imports(acc: &mut Assists, ctx: &AssistContext) -> Option<()
     if let Some(use_item) = tree.syntax().parent().and_then(ast::Use::cast) {
         let (merged, to_remove) =
             next_prev().filter_map(|dir| neighbor(&use_item, dir)).find_map(|use_item2| {
-                try_merge_imports(&use_item, &use_item2, MergeBehavior::Full).zip(Some(use_item2))
+                try_merge_imports(&use_item, &use_item2, MergeBehavior::Crate).zip(Some(use_item2))
             })?;
 
         imports = Some((use_item, merged, to_remove));
     } else {
         let (merged, to_remove) =
             next_prev().filter_map(|dir| neighbor(&tree, dir)).find_map(|use_tree| {
-                try_merge_trees(&tree, &use_tree, MergeBehavior::Full).zip(Some(use_tree))
+                try_merge_trees(&tree, &use_tree, MergeBehavior::Crate).zip(Some(use_tree))
             })?;
 
         uses = Some((tree.clone(), merged, to_remove))
diff --git a/crates/ide_assists/src/handlers/move_bounds.rs b/crates/ide_assists/src/handlers/move_bounds.rs
index 011a28d44..fa3f76609 100644
--- a/crates/ide_assists/src/handlers/move_bounds.rs
+++ b/crates/ide_assists/src/handlers/move_bounds.rs
@@ -63,11 +63,7 @@ pub(crate) fn move_bounds_to_where_clause(acc: &mut Assists, ctx: &AssistContext
 }
 
 fn build_predicate(param: ast::TypeParam) -> Option<ast::WherePred> {
-    let path = {
-        let name_ref = make::name_ref(&param.name()?.syntax().to_string());
-        let segment = make::path_segment(name_ref);
-        make::path_unqualified(segment)
-    };
+    let path = make::ext::ident_path(&param.name()?.syntax().to_string());
     let predicate = make::where_pred(path, param.type_bound_list()?.bounds());
     Some(predicate.clone_for_update())
 }
diff --git a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
index 694d897d1..10d9cec31 100644
--- a/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
+++ b/crates/ide_assists/src/handlers/replace_derive_with_manual_impl.rs
@@ -84,7 +84,7 @@ pub(crate) fn replace_derive_with_manual_impl(
         add_assist(acc, ctx, &attr, &args, &trait_path, Some(trait_), &adt)?;
     }
     if no_traits_found {
-        let trait_path = make::path_unqualified(make::path_segment(make::name_ref(trait_name)));
+        let trait_path = make::ext::ident_path(trait_name);
         add_assist(acc, ctx, &attr, &args, &trait_path, None, &adt)?;
     }
     Some(())
@@ -159,10 +159,8 @@ fn impl_def_from_trait(
     if trait_items.is_empty() {
         return None;
     }
-    let impl_def = make::impl_trait(
-        trait_path.clone(),
-        make::path_unqualified(make::path_segment(make::name_ref(&annotated_name.text()))),
-    );
+    let impl_def =
+        make::impl_trait(trait_path.clone(), make::ext::ident_path(&annotated_name.text()));
     let (impl_def, first_assoc_item) =
         add_trait_assoc_items_to_impl(sema, trait_items, trait_, impl_def, target_scope);
     Some((impl_def, first_assoc_item))
diff --git a/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs b/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
index ff25b61ea..15420aedf 100644
--- a/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
+++ b/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
@@ -1,6 +1,9 @@
-use syntax::ast::{self, edit::AstNodeEdit, make, AstNode, GenericParamsOwner};
+use syntax::{
+    ast::{self, edit_in_place::GenericParamsOwnerEdit, make, AstNode},
+    ted,
+};
 
-use crate::{AssistContext, AssistId, AssistKind, Assists};
+use crate::{utils::suggest_name, AssistContext, AssistId, AssistKind, Assists};
 
 // Assist: replace_impl_trait_with_generic
 //
@@ -17,30 +20,29 @@ pub(crate) fn replace_impl_trait_with_generic(
     acc: &mut Assists,
     ctx: &AssistContext,
 ) -> Option<()> {
-    let type_impl_trait = ctx.find_node_at_offset::<ast::ImplTraitType>()?;
-    let type_param = type_impl_trait.syntax().parent().and_then(ast::Param::cast)?;
-    let type_fn = type_param.syntax().ancestors().find_map(ast::Fn::cast)?;
+    let impl_trait_type = ctx.find_node_at_offset::<ast::ImplTraitType>()?;
+    let param = impl_trait_type.syntax().parent().and_then(ast::Param::cast)?;
+    let fn_ = param.syntax().ancestors().find_map(ast::Fn::cast)?;
 
-    let impl_trait_ty = type_impl_trait.type_bound_list()?;
+    let type_bound_list = impl_trait_type.type_bound_list()?;
 
-    let target = type_fn.syntax().text_range();
+    let target = fn_.syntax().text_range();
     acc.add(
         AssistId("replace_impl_trait_with_generic", AssistKind::RefactorRewrite),
         "Replace impl trait with generic",
         target,
         |edit| {
-            let generic_letter = impl_trait_ty.to_string().chars().next().unwrap().to_string();
+            let impl_trait_type = edit.make_ast_mut(impl_trait_type);
+            let fn_ = edit.make_ast_mut(fn_);
 
-            let generic_param_list = type_fn
-                .generic_param_list()
-                .unwrap_or_else(|| make::generic_param_list(None))
-                .append_param(make::generic_param(generic_letter.clone(), Some(impl_trait_ty)));
+            let type_param_name = suggest_name::for_generic_parameter(&impl_trait_type);
 
-            let new_type_fn = type_fn
-                .replace_descendant::<ast::Type>(type_impl_trait.into(), make::ty(&generic_letter))
-                .with_generic_param_list(generic_param_list);
+            let type_param = make::type_param(make::name(&type_param_name), Some(type_bound_list))
+                .clone_for_update();
+            let new_ty = make::ty(&type_param_name).clone_for_update();
 
-            edit.replace_ast(type_fn.clone(), new_type_fn);
+            ted::replace(impl_trait_type.syntax(), new_ty.syntax());
+            fn_.get_or_create_generic_param_list().add_generic_param(type_param.into())
         },
     )
 }
@@ -55,12 +57,8 @@ mod tests {
     fn replace_impl_trait_with_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<G>(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<G, B: Bar>(bar: B) {}
-            "#,
+            r#"fn foo<G>(bar: $0impl Bar) {}"#,
+            r#"fn foo<G, B: Bar>(bar: B) {}"#,
         );
     }
 
@@ -68,12 +66,8 @@ mod tests {
     fn replace_impl_trait_without_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<B: Bar>(bar: B) {}
-            "#,
+            r#"fn foo(bar: $0impl Bar) {}"#,
+            r#"fn foo<B: Bar>(bar: B) {}"#,
         );
     }
 
@@ -81,12 +75,8 @@ mod tests {
     fn replace_two_impl_trait_with_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<G>(foo: impl Foo, bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<G, B: Bar>(foo: impl Foo, bar: B) {}
-            "#,
+            r#"fn foo<G>(foo: impl Foo, bar: $0impl Bar) {}"#,
+            r#"fn foo<G, B: Bar>(foo: impl Foo, bar: B) {}"#,
         );
     }
 
@@ -94,12 +84,8 @@ mod tests {
     fn replace_impl_trait_with_empty_generic_params() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<>(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<B: Bar>(bar: B) {}
-            "#,
+            r#"fn foo<>(bar: $0impl Bar) {}"#,
+            r#"fn foo<B: Bar>(bar: B) {}"#,
         );
     }
 
@@ -108,13 +94,13 @@ mod tests {
         check_assist(
             replace_impl_trait_with_generic,
             r#"
-            fn foo<
-            >(bar: $0impl Bar) {}
-            "#,
+fn foo<
+>(bar: $0impl Bar) {}
+"#,
             r#"
-            fn foo<B: Bar
-            >(bar: B) {}
-            "#,
+fn foo<B: Bar
+>(bar: B) {}
+"#,
         );
     }
 
@@ -123,12 +109,8 @@ mod tests {
     fn replace_impl_trait_with_exist_generic_letter() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo<B>(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<B, C: Bar>(bar: C) {}
-            "#,
+            r#"fn foo<B>(bar: $0impl Bar) {}"#,
+            r#"fn foo<B, C: Bar>(bar: C) {}"#,
         );
     }
 
@@ -137,19 +119,19 @@ mod tests {
         check_assist(
             replace_impl_trait_with_generic,
             r#"
-            fn foo<
-                G: Foo,
-                F,
-                H,
-            >(bar: $0impl Bar) {}
-            "#,
-            r#"
-            fn foo<
-                G: Foo,
-                F,
-                H, B: Bar
-            >(bar: B) {}
-            "#,
+fn foo<
+    G: Foo,
+    F,
+    H,
+>(bar: $0impl Bar) {}
+"#,
+            r#"
+fn foo<
+    G: Foo,
+    F,
+    H, B: Bar,
+>(bar: B) {}
+"#,
         );
     }
 
@@ -157,12 +139,8 @@ mod tests {
     fn replace_impl_trait_multiple() {
         check_assist(
             replace_impl_trait_with_generic,
-            r#"
-            fn foo(bar: $0impl Foo + Bar) {}
-            "#,
-            r#"
-            fn foo<F: Foo + Bar>(bar: F) {}
-            "#,
+            r#"fn foo(bar: $0impl Foo + Bar) {}"#,
+            r#"fn foo<F: Foo + Bar>(bar: F) {}"#,
         );
     }
 }
diff --git a/crates/ide_assists/src/handlers/replace_let_with_if_let.rs b/crates/ide_assists/src/handlers/replace_let_with_if_let.rs
index be7e724b5..1ad0fa816 100644
--- a/crates/ide_assists/src/handlers/replace_let_with_if_let.rs
+++ b/crates/ide_assists/src/handlers/replace_let_with_if_let.rs
@@ -50,22 +50,19 @@ pub(crate) fn replace_let_with_if_let(acc: &mut Assists, ctx: &AssistContext) ->
         "Replace with if-let",
         target,
         |edit| {
-            let with_placeholder: ast::Pat = match happy_variant {
-                None => make::wildcard_pat().into(),
-                Some(var_name) => make::tuple_struct_pat(
-                    make::path_unqualified(make::path_segment(make::name_ref(var_name))),
-                    once(make::wildcard_pat().into()),
-                )
-                .into(),
+            let pat = match happy_variant {
+                None => original_pat,
+                Some(var_name) => {
+                    make::tuple_struct_pat(make::ext::ident_path(var_name), once(original_pat))
+                        .into()
+                }
             };
+
             let block =
-                make::block_expr(None, None).indent(IndentLevel::from_node(let_stmt.syntax()));
-            let if_ = make::expr_if(make::condition(init, Some(with_placeholder)), block, None);
+                make::ext::empty_block_expr().indent(IndentLevel::from_node(let_stmt.syntax()));
+            let if_ = make::expr_if(make::condition(init, Some(pat)), block, None);
             let stmt = make::expr_stmt(if_);
 
-            let placeholder = stmt.syntax().descendants().find_map(ast::WildcardPat::cast).unwrap();
-            let stmt = stmt.replace_descendant(placeholder.into(), original_pat);
-
             edit.replace_ast(ast::Stmt::from(let_stmt), ast::Stmt::from(stmt));
         },
     )
diff --git a/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs b/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
index a986a6ae8..0fec961b4 100644
--- a/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
+++ b/crates/ide_assists/src/handlers/replace_unwrap_with_match.rs
@@ -32,7 +32,7 @@ use ide_db::ty_filter::TryEnum;
 // fn main() {
 //     let x: Result<i32, i32> = Result::Ok(92);
 //     let y = match x {
-//         Ok(a) => a,
+//         Ok(it) => it,
 //         $0_ => unreachable!(),
 //     };
 // }
@@ -52,16 +52,17 @@ pub(crate) fn replace_unwrap_with_match(acc: &mut Assists, ctx: &AssistContext)
         "Replace unwrap with match",
         target,
         |builder| {
-            let ok_path = make::path_unqualified(make::path_segment(make::name_ref(happy_variant)));
-            let it = make::ident_pat(make::name("a")).into();
+            let ok_path = make::ext::ident_path(happy_variant);
+            let it = make::ident_pat(make::name("it")).into();
             let ok_tuple = make::tuple_struct_pat(ok_path, iter::once(it)).into();
 
-            let bind_path = make::path_unqualified(make::path_segment(make::name_ref("a")));
+            let bind_path = make::ext::ident_path("it");
             let ok_arm = make::match_arm(iter::once(ok_tuple), make::expr_path(bind_path));
 
-            let unreachable_call = make::expr_unreachable();
-            let err_arm =
-                make::match_arm(iter::once(make::wildcard_pat().into()), unreachable_call);
+            let err_arm = make::match_arm(
+                iter::once(make::wildcard_pat().into()),
+                make::ext::expr_unreachable(),
+            );
 
             let match_arm_list = make::match_arm_list(vec![ok_arm, err_arm]);
             let match_expr = make::expr_match(caller.clone(), match_arm_list)
@@ -110,7 +111,7 @@ fn i<T>(a: T) -> T { a }
 fn main() {
     let x: Result<i32, i32> = Result::Ok(92);
     let y = match i(x) {
-        Ok(a) => a,
+        Ok(it) => it,
         $0_ => unreachable!(),
     };
 }
@@ -136,7 +137,7 @@ fn i<T>(a: T) -> T { a }
 fn main() {
     let x = Option::Some(92);
     let y = match i(x) {
-        Some(a) => a,
+        Some(it) => it,
         $0_ => unreachable!(),
     };
 }
@@ -162,7 +163,7 @@ fn i<T>(a: T) -> T { a }
 fn main() {
     let x: Result<i32, i32> = Result::Ok(92);
     let y = match i(x) {
-        Ok(a) => a,
+        Ok(it) => it,
         $0_ => unreachable!(),
     }.count_zeroes();
 }
diff --git a/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs b/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
index e838630ea..2f1da82c7 100644
--- a/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
+++ b/crates/ide_assists/src/handlers/wrap_return_type_in_result.rs
@@ -54,9 +54,7 @@ pub(crate) fn wrap_return_type_in_result(acc: &mut Assists, ctx: &AssistContext)
 
             for ret_expr_arg in tail_return_expr_collector.exprs_to_wrap {
                 let ok_wrapped = make::expr_call(
-                    make::expr_path(make::path_unqualified(make::path_segment(make::name_ref(
-                        "Ok",
-                    )))),
+                    make::expr_path(make::ext::ident_path("Ok")),
                     make::arg_list(iter::once(ret_expr_arg.clone())),
                 );
                 builder.replace_ast(ret_expr_arg, ok_wrapped);
diff --git a/crates/ide_assists/src/tests.rs b/crates/ide_assists/src/tests.rs
index 9c2847998..0d3969c36 100644
--- a/crates/ide_assists/src/tests.rs
+++ b/crates/ide_assists/src/tests.rs
@@ -21,7 +21,7 @@ pub(crate) const TEST_CONFIG: AssistConfig = AssistConfig {
     snippet_cap: SnippetCap::new(true),
     allowed: None,
     insert_use: InsertUseConfig {
-        merge: Some(MergeBehavior::Full),
+        merge: Some(MergeBehavior::Crate),
         prefix_kind: hir::PrefixKind::Plain,
         group: true,
     },
diff --git a/crates/ide_assists/src/tests/generated.rs b/crates/ide_assists/src/tests/generated.rs
index 59bcef8fb..49c1a9776 100644
--- a/crates/ide_assists/src/tests/generated.rs
+++ b/crates/ide_assists/src/tests/generated.rs
@@ -1531,7 +1531,7 @@ enum Result<T, E> { Ok(T), Err(E) }
 fn main() {
     let x: Result<i32, i32> = Result::Ok(92);
     let y = match x {
-        Ok(a) => a,
+        Ok(it) => it,
         $0_ => unreachable!(),
     };
 }
diff --git a/crates/ide_assists/src/utils.rs b/crates/ide_assists/src/utils.rs
index 5a90ad715..0dcf20c61 100644
--- a/crates/ide_assists/src/utils.rs
+++ b/crates/ide_assists/src/utils.rs
@@ -159,8 +159,8 @@ pub fn add_trait_assoc_items_to_impl(
         match fn_def.body() {
             Some(_) => fn_def,
             None => {
-                let body =
-                    make::block_expr(None, Some(make::expr_todo())).indent(edit::IndentLevel(1));
+                let body = make::block_expr(None, Some(make::ext::expr_todo()))
+                    .indent(edit::IndentLevel(1));
                 fn_def.with_body(body)
             }
         }
diff --git a/crates/ide_assists/src/utils/suggest_name.rs b/crates/ide_assists/src/utils/suggest_name.rs
index deafcd630..b3aabeab3 100644
--- a/crates/ide_assists/src/utils/suggest_name.rs
+++ b/crates/ide_assists/src/utils/suggest_name.rs
@@ -6,7 +6,7 @@ use itertools::Itertools;
 use stdx::to_lower_snake_case;
 use syntax::{
     ast::{self, NameOwner},
-    match_ast, AstNode,
+    match_ast, AstNode, SmolStr,
 };
 
 /// Trait names, that will be ignored when in `impl Trait` and `dyn Trait`
@@ -57,6 +57,14 @@ const USELESS_METHODS: &[&str] = &[
     "iter_mut",
 ];
 
+pub(crate) fn for_generic_parameter(ty: &ast::ImplTraitType) -> SmolStr {
+    let c = ty
+        .type_bound_list()
+        .and_then(|bounds| bounds.syntax().text().char_at(0.into()))
+        .unwrap_or('T');
+    c.encode_utf8(&mut [0; 4]).into()
+}
+
 /// Suggest name of variable for given expression
 ///
 /// **NOTE**: it is caller's responsibility to guarantee uniqueness of the name.
@@ -75,7 +83,8 @@ const USELESS_METHODS: &[&str] = &[
 /// It also applies heuristics to filter out less informative names
 ///
 /// Currently it sticks to the first name found.
-pub(crate) fn variable(expr: &ast::Expr, sema: &Semantics<'_, RootDatabase>) -> String {
+// FIXME: Microoptimize and return a `SmolStr` here.
+pub(crate) fn for_variable(expr: &ast::Expr, sema: &Semantics<'_, RootDatabase>) -> String {
     // `from_param` does not benifit from stripping
     // it need the largest context possible
     // so we check firstmost
@@ -276,7 +285,7 @@ mod tests {
             frange.range,
             "selection is not an expression(yet contained in one)"
         );
-        let name = variable(&expr, &sema);
+        let name = for_variable(&expr, &sema);
         assert_eq!(&name, expected);
     }