diff options
| -rw-r--r-- | crates/ide-assists/src/handlers/introduce_named_generic.rs | 20 | ||||
| -rw-r--r-- | crates/ide-assists/src/utils/suggest_name.rs | 35 |
2 files changed, 43 insertions, 12 deletions
diff --git a/crates/ide-assists/src/handlers/introduce_named_generic.rs b/crates/ide-assists/src/handlers/introduce_named_generic.rs index e90a1ed79b4..b1daa7802ed 100644 --- a/crates/ide-assists/src/handlers/introduce_named_generic.rs +++ b/crates/ide-assists/src/handlers/introduce_named_generic.rs @@ -31,15 +31,16 @@ pub(crate) fn introduce_named_generic(acc: &mut Assists, ctx: &AssistContext<'_> |edit| { let impl_trait_type = edit.make_mut(impl_trait_type); let fn_ = edit.make_mut(fn_); - - let type_param_name = suggest_name::for_generic_parameter(&impl_trait_type); + let fn_generic_param_list = fn_.get_or_create_generic_param_list(); + let type_param_name = + suggest_name::for_impl_trait_as_generic(&impl_trait_type, &fn_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(); ted::replace(impl_trait_type.syntax(), new_ty.syntax()); - fn_.get_or_create_generic_param_list().add_generic_param(type_param.into()); + fn_generic_param_list.add_generic_param(type_param.into()); if let Some(cap) = ctx.config.snippet_cap { if let Some(generic_param) = @@ -111,12 +112,19 @@ fn foo<$0B: Bar #[test] fn replace_impl_trait_with_exist_generic_letter() { - // FIXME: This is wrong, we should pick a different name if the one we - // want is already bound. check_assist( introduce_named_generic, r#"fn foo<B>(bar: $0impl Bar) {}"#, - r#"fn foo<B, $0B: Bar>(bar: B) {}"#, + r#"fn foo<B, $0B0: Bar>(bar: B0) {}"#, + ); + } + + #[test] + fn replace_impl_trait_with_more_exist_generic_letter() { + check_assist( + introduce_named_generic, + r#"fn foo<B, B0, B1, B3>(bar: $0impl Bar) {}"#, + r#"fn foo<B, B0, B1, B3, $0B2: Bar>(bar: B2) {}"#, ); } diff --git a/crates/ide-assists/src/utils/suggest_name.rs b/crates/ide-assists/src/utils/suggest_name.rs index 05d38117d43..b4c6cbff2a4 100644 --- a/crates/ide-assists/src/utils/suggest_name.rs +++ b/crates/ide-assists/src/utils/suggest_name.rs @@ -1,5 +1,7 @@ //! This module contains functions to suggest names for expressions, functions and other items +use std::collections::HashSet; + use hir::Semantics; use ide_db::RootDatabase; use itertools::Itertools; @@ -58,6 +60,14 @@ const USELESS_METHODS: &[&str] = &[ "into_future", ]; +/// Suggest a unique name for generic parameter. +/// +/// `existing_params` is used to check if the name conflicts with existing +/// generic parameters. +/// +/// The function checks if the name conflicts with existing generic parameters. +/// If so, it will try to resolve the conflict by adding a number suffix, e.g. +/// `T`, `T0`, `T1`, ... pub(crate) fn for_unique_generic_name( name: &str, existing_params: &ast::GenericParamList, @@ -68,12 +78,9 @@ pub(crate) fn for_unique_generic_name( ast::GenericParam::TypeParam(t) => t.name().unwrap().to_string(), p => p.to_string(), }) - .collect_vec(); + .collect::<HashSet<_>>(); let mut name = name.to_string(); let base_len = name.len(); - // 4*len bytes for base, and 2 bytes for 2 digits - name.reserve(4 * base_len + 2); - let mut count = 0; while param_names.contains(&name) { name.truncate(base_len); @@ -84,12 +91,28 @@ pub(crate) fn for_unique_generic_name( name.into() } -pub(crate) fn for_generic_parameter(ty: &ast::ImplTraitType) -> SmolStr { +/// Suggest name of impl trait type +/// +/// `existing_params` is used to check if the name conflicts with existing +/// generic parameters. +/// +/// # Current implementation +/// +/// In current implementation, the function tries to get the name from the first +/// character of the name for the first type bound. +/// +/// If the name conflicts with existing generic parameters, it will try to +/// resolve the conflict with `for_unique_generic_name`. +pub(crate) fn for_impl_trait_as_generic( + ty: &ast::ImplTraitType, + existing_params: &ast::GenericParamList, +) -> 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() + + for_unique_generic_name(c.encode_utf8(&mut [0; 4]), existing_params) } /// Suggest name of variable for given expression |