diff options
Diffstat (limited to 'book/src/development/method_checking.md')
| -rw-r--r-- | book/src/development/method_checking.md | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/book/src/development/method_checking.md b/book/src/development/method_checking.md index 56d1be37519..9c5d4b516db 100644 --- a/book/src/development/method_checking.md +++ b/book/src/development/method_checking.md @@ -3,8 +3,8 @@ In some scenarios we might want to check for methods when developing a lint. There are two kinds of questions that we might be curious about: -- Invocation: Does an expression call a specific method? -- Definition: Does an `impl` define a method? +- Invocation: Does an expression call a specific method? +- Definition: Does an `impl` define a method? ## Checking if an `expr` is calling a specific method @@ -23,7 +23,7 @@ impl<'tcx> LateLintPass<'tcx> for OurFancyMethodLint { // Check our expr is calling a method with pattern matching if let hir::ExprKind::MethodCall(path, _, [self_arg, ..]) = &expr.kind // Check if the name of this method is `our_fancy_method` - && path.ident.name == sym!(our_fancy_method) + && path.ident.name.as_str() == "our_fancy_method" // We can check the type of the self argument whenever necessary. // (It's necessary if we want to check that method is specifically belonging to a specific trait, // for example, a `map` method could belong to user-defined trait instead of to `Iterator`) @@ -41,10 +41,6 @@ information on the pattern matching. As mentioned in [Define Lints](defining_lints.md#lint-types), the `methods` lint type is full of pattern matching with `MethodCall` in case the reader wishes to explore more. -Additionally, we use the [`clippy_utils::sym!`][sym] macro to conveniently -convert an input `our_fancy_method` into a `Symbol` and compare that symbol to -the [`Ident`]'s name in the [`PathSegment`] in the [`MethodCall`]. - ## Checking if a `impl` block implements a method While sometimes we want to check whether a method is being called or not, other @@ -71,7 +67,7 @@ impl<'tcx> LateLintPass<'tcx> for MyTypeImpl { // Check if item is a method/function if let ImplItemKind::Fn(ref signature, _) = impl_item.kind // Check the method is named `our_fancy_method` - && impl_item.ident.name == sym!(our_fancy_method) + && impl_item.ident.name.as_str() == "our_fancy_method" // We can also check it has a parameter `self` && signature.decl.implicit_self.has_implicit_self() // We can go even further and even check if its return type is `String` @@ -85,9 +81,6 @@ impl<'tcx> LateLintPass<'tcx> for MyTypeImpl { [`check_impl_item`]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_lint/trait.LateLintPass.html#method.check_impl_item [`ExprKind`]: https://doc.rust-lang.org/beta/nightly-rustc/rustc_hir/hir/enum.ExprKind.html -[`Ident`]: https://doc.rust-lang.org/beta/nightly-rustc/rustc_span/symbol/struct.Ident.html [`ImplItem`]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_hir/hir/struct.ImplItem.html [`LateLintPass`]: https://doc.rust-lang.org/stable/nightly-rustc/rustc_lint/trait.LateLintPass.html [`MethodCall`]: https://doc.rust-lang.org/beta/nightly-rustc/rustc_hir/hir/enum.ExprKind.html#variant.MethodCall -[`PathSegment`]: https://doc.rust-lang.org/beta/nightly-rustc/rustc_hir/hir/struct.PathSegment.html -[sym]: https://doc.rust-lang.org/stable/nightly-rustc/clippy_utils/macro.sym.html |