@yongtang I think this will make #29161 cleaner. No need to pass in stderr, you can just return Warnings as part of Result() and handle them in the builder.

Thanks @dnephin I am on the road but will try to take a look and update #29161 in the next several days. (my flight is with united airline 😢)

@dnephin Hmmm, just seen this. By having processFirstLine separate from processLine, it means adding additional parse directives is very problematic (which is what I'm currently trying to do in another PR).

What was the rationale for splitting the first line out and not just treating every line as "just another line".

Oh, I see. It's the BOM handling. I'll figure it out :)

Ya, I was thinking about that case when I was making these changes, but didn't want to worry about it in case we never added another directive.

I think d.processLine() can be called in both cases, and the Directive() d.processingComplete = true can be set to true on the first non-directive line, instead of after the first line.