Prevent rebuilds due to different order of tokens in ct_token_map

Author: taminomara

lrlex/src/lib/ctbuilder.rs

@@ -1205,9 +1205,12 @@ pub fn ct_token_map<StorageT: Display + ToTokens>(
     let timestamp = env!("VERGEN_BUILD_TIMESTAMP");
     let mod_ident = format_ident!("{}", mod_name);
     write!(outs, "// lrlex build time: {}\n\n", quote!(#timestamp),).ok();
-    let tokens = &token_map
-        .borrow()
-        .iter()
+    // Sort the tokens so that they're always in the same order.
+    // This will prevent unneeded rebuilds.
+    let mut token_map_sorted = Vec::from_iter(token_map.borrow().iter());
+    token_map_sorted.sort_by_key(|(k, _)| *k);
+    let tokens = &token_map_sorted
+        .into_iter()
         .map(|(k, id)| {
             let name = match rename_map {
                 Some(rmap) => *rmap.get(k.as_str()).unwrap_or(&k.as_str()),