extended_range computes the range for a library entry, that includes the original range for the entry, but where the stop offset of the range may be shifted to the right, until the end of the line, if this captures a comment placed on the same line as the value.

For example:

 (libraries
    foo
    bar ;; a comment for bar on the same line
    baz)

extended_range foo will be foo's original range unchanged. And extended_range bar will include bar and its comment too.

A convenient wrapper for extended_range that specializes to sexp arguments found when rewritting sexps with Sexps_rewriter.

A convenient wrapper that extracts and returns the substring matching the entire extended_range from the original contents.