Unnamed repository; edit this file 'description' to name the repository.
Diffstat (limited to 'crates/ide-assists/src/handlers/generate_mut_trait_impl.rs')
| -rw-r--r-- | crates/ide-assists/src/handlers/generate_mut_trait_impl.rs | 202 |
1 files changed, 202 insertions, 0 deletions
diff --git a/crates/ide-assists/src/handlers/generate_mut_trait_impl.rs b/crates/ide-assists/src/handlers/generate_mut_trait_impl.rs new file mode 100644 index 0000000000..cb8ef39565 --- /dev/null +++ b/crates/ide-assists/src/handlers/generate_mut_trait_impl.rs @@ -0,0 +1,202 @@ +use ide_db::famous_defs::FamousDefs; +use syntax::{ + ast::{self, make}, + ted, AstNode, +}; + +use crate::{AssistContext, AssistId, AssistKind, Assists}; + +// FIXME: Generate proper `index_mut` method body refer to `index` method body may impossible due to the unpredicable case [#15581]. +// Here just leave the `index_mut` method body be same as `index` method body, user can modify it manually to meet their need. + +// Assist: generate_mut_trait_impl +// +// Adds a IndexMut impl from the `Index` trait. +// +// ``` +// # //- minicore: index +// pub enum Axis { X = 0, Y = 1, Z = 2 } +// +// impl<T> core::ops::Index$0<Axis> for [T; 3] { +// type Output = T; +// +// fn index(&self, index: Axis) -> &Self::Output { +// &self[index as usize] +// } +// } +// ``` +// -> +// ``` +// pub enum Axis { X = 0, Y = 1, Z = 2 } +// +// $0impl<T> core::ops::IndexMut<Axis> for [T; 3] { +// fn index_mut(&mut self, index: Axis) -> &mut Self::Output { +// &self[index as usize] +// } +// } +// +// impl<T> core::ops::Index<Axis> for [T; 3] { +// type Output = T; +// +// fn index(&self, index: Axis) -> &Self::Output { +// &self[index as usize] +// } +// } +// ``` +pub(crate) fn generate_mut_trait_impl(acc: &mut Assists, ctx: &AssistContext<'_>) -> Option<()> { + let impl_def = ctx.find_node_at_offset::<ast::Impl>()?.clone_for_update(); + + let trait_ = impl_def.trait_()?; + if let ast::Type::PathType(trait_path) = trait_.clone() { + let trait_type = ctx.sema.resolve_trait(&trait_path.path()?)?; + let scope = ctx.sema.scope(trait_path.syntax())?; + if trait_type != FamousDefs(&ctx.sema, scope.krate()).core_convert_Index()? { + return None; + } + } + + // Index -> IndexMut + let index_trait = impl_def + .syntax() + .descendants() + .filter_map(ast::NameRef::cast) + .find(|it| it.text() == "Index")?; + ted::replace( + index_trait.syntax(), + make::path_segment(make::name_ref("IndexMut")).clone_for_update().syntax(), + ); + + // index -> index_mut + let trait_method_name = impl_def + .syntax() + .descendants() + .filter_map(ast::Name::cast) + .find(|it| it.text() == "index")?; + ted::replace(trait_method_name.syntax(), make::name("index_mut").clone_for_update().syntax()); + + let type_alias = impl_def.syntax().descendants().find_map(ast::TypeAlias::cast)?; + ted::remove(type_alias.syntax()); + + // &self -> &mut self + let mut_self_param = make::mut_self_param(); + let self_param: ast::SelfParam = + impl_def.syntax().descendants().find_map(ast::SelfParam::cast)?; + ted::replace(self_param.syntax(), mut_self_param.clone_for_update().syntax()); + + // &Self::Output -> &mut Self::Output + let ret_type = impl_def.syntax().descendants().find_map(ast::RetType::cast)?; + ted::replace( + ret_type.syntax(), + make::ret_type(make::ty("&mut Self::Output")).clone_for_update().syntax(), + ); + + let fn_ = impl_def.assoc_item_list()?.assoc_items().find_map(|it| match it { + ast::AssocItem::Fn(f) => Some(f), + _ => None, + })?; + + let assoc_list = make::assoc_item_list().clone_for_update(); + assoc_list.add_item(syntax::ast::AssocItem::Fn(fn_)); + ted::replace(impl_def.assoc_item_list()?.syntax(), assoc_list.syntax()); + + let target = impl_def.syntax().text_range(); + acc.add( + AssistId("generate_mut_trait_impl", AssistKind::Generate), + "Generate `IndexMut` impl from this `Index` trait", + target, + |edit| { + edit.insert(target.start(), format!("$0{}\n\n", impl_def.to_string())); + }, + ) +} + +#[cfg(test)] +mod tests { + use crate::tests::{check_assist, check_assist_not_applicable}; + + use super::*; + + #[test] + fn test_generate_mut_trait_impl() { + check_assist( + generate_mut_trait_impl, + r#" +//- minicore: index +pub enum Axis { X = 0, Y = 1, Z = 2 } + +impl<T> core::ops::Index$0<Axis> for [T; 3] { + type Output = T; + + fn index(&self, index: Axis) -> &Self::Output { + &self[index as usize] + } +} +"#, + r#" +pub enum Axis { X = 0, Y = 1, Z = 2 } + +$0impl<T> core::ops::IndexMut<Axis> for [T; 3] { + fn index_mut(&mut self, index: Axis) -> &mut Self::Output { + &self[index as usize] + } +} + +impl<T> core::ops::Index<Axis> for [T; 3] { + type Output = T; + + fn index(&self, index: Axis) -> &Self::Output { + &self[index as usize] + } +} +"#, + ); + + check_assist( + generate_mut_trait_impl, + r#" +//- minicore: index +pub enum Axis { X = 0, Y = 1, Z = 2 } + +impl<T> core::ops::Index$0<Axis> for [T; 3] where T: Copy { + type Output = T; + + fn index(&self, index: Axis) -> &Self::Output { + let var_name = &self[index as usize]; + var_name + } +} +"#, + r#" +pub enum Axis { X = 0, Y = 1, Z = 2 } + +$0impl<T> core::ops::IndexMut<Axis> for [T; 3] where T: Copy { + fn index_mut(&mut self, index: Axis) -> &mut Self::Output { + let var_name = &self[index as usize]; + var_name + } +} + +impl<T> core::ops::Index<Axis> for [T; 3] where T: Copy { + type Output = T; + + fn index(&self, index: Axis) -> &Self::Output { + let var_name = &self[index as usize]; + var_name + } +} +"#, + ); + } + + #[test] + fn test_generate_mut_trait_impl_not_applicable() { + check_assist_not_applicable( + generate_mut_trait_impl, + r#" +pub trait Index<Idx: ?Sized> {} + +impl<T> Index$0<i32> for [T; 3] {} +"#, + ); + } +} |