Update book

Author: GnomedDev

book/src/development/common_tools_writing_lints.md

@@ -68,7 +68,7 @@ impl<'tcx> LateLintPass<'tcx> for MyStructLint {
         // Check our expr is calling a method
         if let hir::ExprKind::MethodCall(path, _, _self_arg, ..) = &expr.kind
             // Check the name of this method is `some_method`
-            && path.ident.name == sym!(some_method)
+            && path.ident.name.as_str() == "some_method"
             // Optionally, check the type of the self argument.
             // - See "Checking for a specific type"
         {
@@ -167,7 +167,7 @@ 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 `some_method`
-            && impl_item.ident.name == sym!(some_method)
+            && impl_item.ident.name.as_str() == "some_method"
             // We can also check it has a parameter `self`
             && signature.decl.implicit_self.has_implicit_self()
             // We can go further and even check if its return type is `String`

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