deprecate the manual setting of those particular fields, As I recall, Kathy and I wrote all that based on actual usage (Emacs was the main thing we looked at). I am not in favor of "deprecating" anything that has been around so long, precisely because it has been around so long. What is gained? I hope something besides pedantic cleanliness.
paticular, `fastmap' can't be set (you have to call re_compile_fastmap, and `no_sub' can't be set (because re_compile always overwrites it, as it does newline_anchor). I certainly can't remember the state of the code 18 years ago, but simply based on the above quote of what we wrote, I expect that it was true at the time that fastmap and no_sub could be set. We wouldn't have written it otherwise. So someone broke that in the meantime. Obviously life went on. BTW, if you look for "xx" in regex.texi, you'll see more things that we didn't finish back then. And as far as importing it wholesale, I'd be amazed if the RE_ bit settings and API functions haven't changed (been added to, at least) since then. karl