rust-analyzer

diff --git a/crates/ide-assists/src/handlers/generate_impl.rs b/crates/ide-assists/src/handlers/generate_impl.rs
index 68287a20bf..307cea3d0a 100644
--- a/crates/ide-assists/src/handlers/generate_impl.rs
+++ b/crates/ide-assists/src/handlers/generate_impl.rs

@@ -52,6 +52,7 @@ mod tests {

use super::*;

+ // FIXME: break up into separate test fns

#[test]

fn test_add_impl() {

check_assist(

@@ -136,6 +137,18 @@ mod tests {

check_assist(

generate_impl,

+ r#"

+ struct Defaulted<const N: i32 = 0> {}$0"#,

+ r#"

+ struct Defaulted<const N: i32 = 0> {}

+ impl<const N: i32> Defaulted<N> {

+ $0

+ }"#,

+ );

+ check_assist(

+ generate_impl,

r#"pub trait Trait {}

struct Struct<T>$0

where

diff --git a/crates/ide-assists/src/utils.rs b/crates/ide-assists/src/utils.rs
index 4ab6e2627f..38396cd7d7 100644
--- a/crates/ide-assists/src/utils.rs
+++ b/crates/ide-assists/src/utils.rs

@@ -2,8 +2,6 @@

use std::ops;

-use itertools::Itertools;

pub(crate) use gen_trait_fn_body::gen_trait_fn_body;

use hir::{db::HirDatabase, HirDisplay, Semantics};

use ide_db::{famous_defs::FamousDefs, path_transform::PathTransform, RootDatabase, SnippetCap};

@@ -15,7 +13,7 @@ use syntax::{

edit_in_place::{AttrsOwnerEdit, Removable},

make, HasArgList, HasAttrs, HasGenericParams, HasName, HasTypeBounds, Whitespace,

- ted, AstNode, AstToken, Direction, SmolStr, SourceFile,

+ ted, AstNode, AstToken, Direction, SourceFile,

SyntaxKind::*,

SyntaxNode, TextRange, TextSize, T,

};

@@ -424,34 +422,44 @@ pub(crate) fn generate_trait_impl_text(adt: &ast::Adt, trait_text: &str, code: &

}

fn generate_impl_text_inner(adt: &ast::Adt, trait_text: Option<&str>, code: &str) -> String {

- let generic_params = adt.generic_param_list();

+ // Ensure lifetime params are before type & const params

+ let generic_params = adt.generic_param_list().map(|generic_params| {

+ let lifetime_params =

+ generic_params.lifetime_params().map(ast::GenericParam::LifetimeParam);

+ let ty_or_const_params = generic_params.type_or_const_params().filter_map(|param| {

+ // remove defaults since they can't be specified in impls

+ match param {

+ ast::TypeOrConstParam::Type(param) => {

+ let param = param.clone_for_update();

+ param.remove_default();

+ Some(ast::GenericParam::TypeParam(param))

+ }

+ ast::TypeOrConstParam::Const(param) => {

+ let param = param.clone_for_update();

+ param.remove_default();

+ Some(ast::GenericParam::ConstParam(param))

+ }

+ });

+ make::generic_param_list(itertools::chain(lifetime_params, ty_or_const_params))

+ });

+ // FIXME: use syntax::make & mutable AST apis instead

+ // `trait_text` and `code` can't be opaque blobs of text

let mut buf = String::with_capacity(code.len());

+ // Copy any cfg attrs from the original adt

buf.push_str("\n\n");

- adt.attrs()

- .filter(|attr| attr.as_simple_call().map(|(name, _arg)| name == "cfg").unwrap_or(false))

- .for_each(|attr| buf.push_str(format!("{}\n", attr).as_str()));

+ let cfg_attrs = adt

+ .attrs()

+ .filter(|attr| attr.as_simple_call().map(|(name, _arg)| name == "cfg").unwrap_or(false));

+ cfg_attrs.for_each(|attr| buf.push_str(&format!("{attr}\n")));

+ // `impl{generic_params} {trait_text} for {name}{generic_params.to_generic_args()}`

buf.push_str("impl");

if let Some(generic_params) = &generic_params {

- let lifetimes = generic_params.lifetime_params().map(|lt| format!("{}", lt.syntax()));

- let toc_params = generic_params.type_or_const_params().map(|toc_param| {

- let type_param = match toc_param {

- ast::TypeOrConstParam::Type(x) => x,

- ast::TypeOrConstParam::Const(x) => return x.syntax().to_string(),

- };

- let mut buf = String::new();

- if let Some(it) = type_param.name() {

- format_to!(buf, "{}", it.syntax());

- }

- if let Some(it) = type_param.colon_token() {

- format_to!(buf, "{} ", it);

- }

- if let Some(it) = type_param.type_bound_list() {

- format_to!(buf, "{}", it.syntax());

- }

- buf

- });

- let generics = lifetimes.chain(toc_params).format(", ");

- format_to!(buf, "<{}>", generics);

+ format_to!(buf, "{generic_params}");

}

buf.push(' ');

if let Some(trait_text) = trait_text {

@@ -460,23 +468,15 @@ fn generate_impl_text_inner(adt: &ast::Adt, trait_text: Option<&str>, code: &str

}

buf.push_str(&adt.name().unwrap().text());

if let Some(generic_params) = generic_params {

- let lifetime_params = generic_params

- .lifetime_params()

- .filter_map(|it| it.lifetime())

- .map(|it| SmolStr::from(it.text()));

- let toc_params = generic_params

- .type_or_const_params()

- .filter_map(|it| it.name())

- .map(|it| SmolStr::from(it.text()));

- format_to!(buf, "<{}>", lifetime_params.chain(toc_params).format(", "))

+ format_to!(buf, "{}", generic_params.to_generic_args());

}

match adt.where_clause() {

Some(where_clause) => {

- format_to!(buf, "\n{}\n{{\n{}\n}}", where_clause, code);

+ format_to!(buf, "\n{where_clause}\n{{\n{code}\n}}");

}

None => {

- format_to!(buf, " {{\n{}\n}}", code);

+ format_to!(buf, " {{\n{code}\n}}");

}

diff --git a/crates/syntax/src/ast/edit_in_place.rs b/crates/syntax/src/ast/edit_in_place.rs
index 7d63235282..173c064ccc 100644
--- a/crates/syntax/src/ast/edit_in_place.rs
+++ b/crates/syntax/src/ast/edit_in_place.rs

@@ -265,6 +265,42 @@ impl ast::WhereClause {

}

+impl ast::TypeParam {

+ pub fn remove_default(&self) {

+ if let Some((eq, last)) = self

+ .syntax()

+ .children_with_tokens()

+ .find(|it| it.kind() == T![=])

+ .zip(self.syntax().last_child_or_token())

+ {

+ ted::remove_all(eq..=last);

+ // remove any trailing ws

+ if let Some(last) = self.syntax().last_token().filter(|it| it.kind() == WHITESPACE) {

+ last.detach();

+ }

+impl ast::ConstParam {