diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs index 02a5cac1df..f12ced24cc 100644 --- a/crates/hir_ty/src/method_resolution.rs +++ b/crates/hir_ty/src/method_resolution.rs @@ -709,6 +709,33 @@ fn iterate_trait_method_candidates( false } +fn filter_inherent_impls_for_self_ty<'i>( + impls: &'i InherentImpls, + self_ty: &Ty, +) -> impl Iterator { + // inherent methods on arrays are fingerprinted as [T; {unknown}], so we must also consider them when + // resolving a method call on an array with a known len + let array_impls = { + if let TyKind::Array(parameters, array_len) = self_ty.kind(&Interner) { + if !array_len.is_unknown() { + let unknown_array_len_ty = + TyKind::Array(parameters.clone(), consteval::usize_const(None)) + .intern(&Interner); + + Some(impls.for_self_ty(&unknown_array_len_ty)) + } else { + None + } + } else { + None + } + } + .into_iter() + .flatten(); + + impls.for_self_ty(self_ty).iter().chain(array_impls) +} + fn iterate_inherent_methods( self_ty: &Canonical, db: &dyn HirDatabase, @@ -726,25 +753,7 @@ fn iterate_inherent_methods( for krate in def_crates { let impls = db.inherent_impls_in_crate(krate); - let impls_for_self_ty = impls.for_self_ty(&self_ty.value).iter().chain( - { - if let TyKind::Array(parameters, array_len) = self_ty.value.kind(&Interner) { - if !array_len.is_unknown() { - let unknown_array_len_ty = - TyKind::Array(parameters.clone(), consteval::usize_const(None)) - .intern(&Interner); - - Some(impls.for_self_ty(&unknown_array_len_ty)) - } else { - None - } - } else { - None - } - } - .into_iter() - .flatten(), - ); + let impls_for_self_ty = filter_inherent_impls_for_self_ty(&impls, &self_ty.value); for &impl_def in impls_for_self_ty { for &item in db.impl_data(impl_def).items.iter() { @@ -798,6 +807,28 @@ pub fn resolve_indexing_op( None } +fn is_transformed_receiver_ty_equal(transformed_receiver_ty: &Ty, receiver_ty: &Ty) -> bool { + if transformed_receiver_ty == receiver_ty { + return true; + } + + // a transformed receiver may be considered equal (and a valid method call candidate) if it is an array + // with an unknown (i.e. generic) length, and the receiver is an array with the same item type but a known len, + // this allows inherent methods on arrays to be considered valid resolution candidates + match (transformed_receiver_ty.kind(&Interner), receiver_ty.kind(&Interner)) { + ( + TyKind::Array(transformed_array_ty, transformed_array_len), + TyKind::Array(receiver_array_ty, receiver_array_len), + ) if transformed_array_ty == receiver_array_ty + && transformed_array_len.is_unknown() + && !receiver_array_len.is_unknown() => + { + true + } + _ => false, + } +} + fn is_valid_candidate( db: &dyn HirDatabase, env: Arc, @@ -823,21 +854,9 @@ fn is_valid_candidate( Some(ty) => ty, None => return false, }; - if transformed_receiver_ty != receiver_ty.value { - match ( - transformed_receiver_ty.kind(&Interner), - receiver_ty.value.kind(&Interner), - ) { - ( - TyKind::Array(transformed_array_ty, transformed_array_len), - TyKind::Array(receiver_array_ty, receiver_array_len), - ) if transformed_array_ty == receiver_array_ty - && transformed_array_len.is_unknown() - && !receiver_array_len.is_unknown() => {} - _ => { - return false; - } - } + + if !is_transformed_receiver_ty_equal(&transformed_receiver_ty, &receiver_ty.value) { + return false; } } if let Some(from_module) = visible_from_module {