Replace unicode-xid with unicode-ident crate

Cargo.toml

@@ -36,9 +36,9 @@ proc-macro = ["proc-macro2/proc-macro", "quote/proc-macro"]
 test = ["syn-test-suite/all-features"]
 
 [dependencies]
-proc-macro2 = { version = "1.0.32", default-features = false }
+proc-macro2 = { version = "1.0.39", default-features = false }
 quote = { version = "1.0", optional = true, default-features = false }
-unicode-xid = "0.2"
+unicode-ident = "1.0"
 
 [dev-dependencies]
 anyhow = "1.0"

src/ident.rs

@@ -6,7 +6,6 @@ use crate::lookahead;
 use crate::parse::{Parse, ParseStream, Result};
 #[cfg(feature = "parsing")]
 use crate::token::Token;
-use unicode_xid::UnicodeXID;
 
 pub use proc_macro2::Ident;
 
@@ -90,11 +89,11 @@ impl From<Token![_]> for Ident {
 pub fn xid_ok(symbol: &str) -> bool {
     let mut chars = symbol.chars();
     let first = chars.next().unwrap();
-    if !(first == '_' || UnicodeXID::is_xid_start(first)) {
+    if !(first == '_' || unicode_ident::is_xid_start(first)) {
         return false;
     }
     for ch in chars {
-        if !UnicodeXID::is_xid_continue(ch) {
+        if !unicode_ident::is_xid_continue(ch) {
             return false;
         }
     }

src/lib.rs

@@ -310,7 +310,6 @@
 ))]
 extern crate proc_macro;
 extern crate proc_macro2;
-extern crate unicode_xid;
 
 #[cfg(feature = "printing")]
 extern crate quote;