Custom lexers can now terminate operators

New constraint: custom lexer output is dropped whenever it is used to terminate an operator nested inside another custom lexer, because the recursive call has to return exactly one lexeme

orchid-extension/src/entrypoint.rs

@@ -277,7 +277,11 @@ impl ExtensionBuilder {
 												return handle.reply(&lex, &eopt).await;
 											},
 											Ok((s, expr)) => {
-												let expr = expr.into_api(&mut (), &mut ()).await;
+												let expr = join_all(
+													(expr.into_iter())
+														.map(|tok| async { tok.into_api(&mut (), &mut ()).await }),
+												)
+												.await;
 												let pos = (text.len() - s.len()) as u32;
 												expr_store.dispose().await;
 												return handle.reply(&lex, &Some(Ok(api::LexedExpr { pos, expr }))).await;