Hi @jackh726,

Thank you for your work on bigtools!

I am currently exploring using bigtools to create bigwig files in one of our rust crates (https://github.com/databio/gtars). Our crate would create intermediate bigwigs before merging them into a single bigwig as a final result.

I thought the best way would be to call the the public function bigwigmerge from bigwigmerge.rs and pass a constructed BigWigMergeArgs struct to the function. However, while the BigWigMergeArgs struct is public, some of the fields are private and I am unable to edit these fields from within another crate.

I also looked at a second option, where I merge the values and write them using BigWigWrite<File>'s wrtie function:

            let all_values = ChromGroupReadImpl {
                iter: Box::new(iter),
            };
            outb.write(all_values, runtime)?;

However, all values is a private struct that implements the necessary BBIDataSource trait.

I guess my questions for you are:

1. Should I be approaching this differently? I could have the user run bigwigmerge [OPTIONS] <OUTPUT> after using our crate, but I thought it would be nicer and less clunky to do this behind the scenes for the user.
2. Could we make the ChromGroupReadImpl struct public? I believe this might be the simplest solution to using the bigtools merge code in another external crate.