4 files changed, 49 insertions, 44 deletions

diff --git a/crates/ide_assists/src/handlers/extract_function.rs b/crates/ide_assists/src/handlers/extract_function.rs
index 4116985ae..494ef4621 100644
--- a/crates/ide_assists/src/handlers/extract_function.rs
+++ b/crates/ide_assists/src/handlers/extract_function.rs
@@ -1192,7 +1192,7 @@ fn make_ret_ty(ctx: &AssistContext, module: hir::Module, fun: &Function) -> Opti
                 vec![fun_ty.make_ty(ctx, module), handler_ty],
             )
         }
-        FlowHandler::If { .. } => make::ty("bool"),
+        FlowHandler::If { .. } => make::ty_bool(),
         FlowHandler::IfOption { action } => {
             let handler_ty = action
                 .expr_ty(ctx)
diff --git a/crates/ide_assists/src/handlers/introduce_named_lifetime.rs b/crates/ide_assists/src/handlers/introduce_named_lifetime.rs
index cb71ca8bd..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/replace_impl_trait_with_generic.rs b/crates/ide_assists/src/handlers/replace_impl_trait_with_generic.rs
index 16cae0281..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
@@ -37,12 +37,12 @@ pub(crate) fn replace_impl_trait_with_generic(
 
             let type_param_name = suggest_name::for_generic_parameter(&impl_trait_type);
 
-            let type_param =
-                make::generic_param(&type_param_name, Some(type_bound_list)).clone_for_update();
+            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();
 
             ted::replace(impl_trait_type.syntax(), new_ty.syntax());
-            fn_.get_or_create_generic_param_list().add_generic_param(type_param)
+            fn_.get_or_create_generic_param_list().add_generic_param(type_param.into())
         },
     )
 }
diff --git a/crates/syntax/src/ast/make.rs b/crates/syntax/src/ast/make.rs
index 2289d8f3e..c39e248ce 100644
--- a/crates/syntax/src/ast/make.rs
+++ b/crates/syntax/src/ast/make.rs
@@ -10,7 +10,7 @@
 //! `parse(format!())` we use internally is an implementation detail -- long
 //! term, it will be replaced with direct tree manipulation.
 use itertools::Itertools;
-use stdx::format_to;
+use stdx::{format_to, never};
 
 use crate::{ast, AstNode, SourceFile, SyntaxKind, SyntaxNode, SyntaxToken};
 
@@ -22,6 +22,16 @@ pub fn name_ref(text: &str) -> ast::NameRef {
     ast_from_text(&format!("fn f() {{ {}{}; }}", raw_ident_esc(text), text))
 }
 
+pub fn lifetime(text: &str) -> ast::Lifetime {
+    let mut text = text;
+    let tmp;
+    if never!(!text.starts_with('\'')) {
+        tmp = format!("'{}", text);
+        text = &tmp;
+    }
+    ast_from_text(&format!("fn f<{}>() {{ }}", text))
+}
+
 fn raw_ident_esc(ident: &str) -> &'static str {
     let is_keyword = parser::SyntaxKind::from_keyword(ident).is_some();
     if is_keyword && !matches!(ident, "self" | "crate" | "super" | "Self") {
@@ -34,10 +44,13 @@ fn raw_ident_esc(ident: &str) -> &'static str {
 // FIXME: replace stringly-typed constructor with a family of typed ctors, a-la
 // `expr_xxx`.
 pub fn ty(text: &str) -> ast::Type {
-    ast_from_text(&format!("fn f() -> {} {{}}", text))
+    ty_from_text(text)
 }
 pub fn ty_unit() -> ast::Type {
-    ty("()")
+    ty_from_text("()")
+}
+pub fn ty_bool() -> ast::Type {
+    ty_path(path_unqualified(path_segment(name_ref("bool"))))
 }
 pub fn ty_tuple(types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
     let mut count: usize = 0;
@@ -46,15 +59,21 @@ pub fn ty_tuple(types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
         contents.push(',');
     }
 
-    ty(&format!("({})", contents))
+    ty_from_text(&format!("({})", contents))
 }
 // FIXME: handle path to type
 pub fn ty_generic(name: ast::NameRef, types: impl IntoIterator<Item = ast::Type>) -> ast::Type {
     let contents = types.into_iter().join(", ");
-    ty(&format!("{}<{}>", name, contents))
+    ty_from_text(&format!("{}<{}>", name, contents))
 }
 pub fn ty_ref(target: ast::Type, exclusive: bool) -> ast::Type {
-    ty(&if exclusive { format!("&mut {}", target) } else { format!("&{}", target) })
+    ty_from_text(&if exclusive { format!("&mut {}", target) } else { format!("&{}", target) })
+}
+pub fn ty_path(path: ast::Path) -> ast::Type {
+    ty_from_text(&path.to_string())
+}
+fn ty_from_text(text: &str) -> ast::Type {
+    ast_from_text(&format!("type _T = {};", text))
 }
 
 pub fn assoc_item_list() -> ast::AssocItemList {
@@ -475,8 +494,8 @@ pub fn param_list(
     };
     ast_from_text(&list)
 }
-// FIXME: s/&str/ast:Name
-pub fn generic_param(name: &str, ty: Option<ast::TypeBoundList>) -> ast::GenericParam {
+
+pub fn type_param(name: ast::Name, ty: Option<ast::TypeBoundList>) -> ast::TypeParam {
     let bound = match ty {
         Some(it) => format!(": {}", it),
         None => String::new(),
@@ -484,6 +503,10 @@ pub fn generic_param(name: &str, ty: Option<ast::TypeBoundList>) -> ast::Generic
     ast_from_text(&format!("fn f<{}{}>() {{ }}", name, bound))
 }
 
+pub fn lifetime_param(lifetime: ast::Lifetime) -> ast::LifetimeParam {
+    ast_from_text(&format!("fn f<{}>() {{ }}", lifetime))
+}
+
 pub fn generic_param_list(
     pats: impl IntoIterator<Item = ast::GenericParam>,
 ) -> ast::GenericParamList {