Infinite loop in error message

[benjaminwinger]

When parsing this file and displaying an error message related to the string err-😂 via lexy_ext::report_error, the output is 12 │ err-⟨U+????⟩⟨U+????⟩, but with the ⟨U+????⟩ repeated for, at the very least, a long time.

I've also tried it with a few other unicode characters and gotten the same result.

[foonathan]

As a temporary fix, you can apply the following diff:

diff --git a/include/lexy/visualize.hpp b/include/lexy/visualize.hpp
index 1ad79fe9..1a12f3cb 100644
--- a/include/lexy/visualize.hpp
+++ b/include/lexy/visualize.hpp
@@ -392,7 +392,8 @@ OutputIt visualize_to(OutputIt out, lexy::lexeme<Reader> lexeme,
         {
             lexy::engine_cp_auto::error_code ec{};
             auto                             cp = lexy::engine_cp_auto::parse(ec, reader);
-            if (ec == lexy::engine_cp_auto::error_code::eof)
+            if (ec != lexy::engine_cp_auto::error_code{}
+                && !lexy::engine_cp_auto::recover(reader, ec))
                 break;
 
             out = visualize_to(out, cp, opts);

I'm not quite happy with the way the error message is rendered (it will split the code point in half and report multiple invalid ones for each byte, as only some code units are underlined), so I'll need to take some time to come up with a proper fix.

[foonathan]

This is now fixed, and it should report an error looking like this: https://lexy.foonathan.net/playground/?id=nEa7KjabK&mode=tree