Generalize proc_macro2 path to other terminal types

Author: dtolnay

codegen/src/fold.rs

@@ -91,7 +91,7 @@ fn visit(
 fn node(traits: &mut TokenStream, impls: &mut TokenStream, s: &Node, defs: &Definitions) {
     let under_name = gen::under_name(&s.ident);
     let ident = Ident::new(&s.ident, Span::call_site());
-    let ty = if let "Ident" | "Span" = s.ident.as_str() {
+    let ty = if gen::TERMINAL_TYPES.contains(&s.ident.as_str()) {
         quote!(proc_macro2::#ident)
     } else {
         quote!(crate::#ident)

codegen/src/visit.rs

@@ -97,7 +97,7 @@ fn visit(
 fn node(traits: &mut TokenStream, impls: &mut TokenStream, s: &Node, defs: &Definitions) {
     let under_name = gen::under_name(&s.ident);
     let ident = Ident::new(&s.ident, Span::call_site());
-    let ty = if let "Ident" | "Span" = s.ident.as_str() {
+    let ty = if gen::TERMINAL_TYPES.contains(&s.ident.as_str()) {
         quote!(proc_macro2::#ident)
     } else {
         quote!(crate::#ident)

codegen/src/visit_mut.rs

@@ -104,7 +104,7 @@ fn visit(
 fn node(traits: &mut TokenStream, impls: &mut TokenStream, s: &Node, defs: &Definitions) {
     let under_name = gen::under_name(&s.ident);
     let ident = Ident::new(&s.ident, Span::call_site());
-    let ty = if let "Ident" | "Span" = s.ident.as_str() {
+    let ty = if gen::TERMINAL_TYPES.contains(&s.ident.as_str()) {
         quote!(proc_macro2::#ident)
     } else {
         quote!(crate::#ident)