Function reg_index::list_all

pub fn list_all(
    index: impl AsRef<Path>, 
    pkg_name: Option<&str>, 
    version_req: Option<&str>, 
    cb: impl FnMut(Vec<IndexPackage>)
) -> Result<(), Error>

List all entries for all packages in the index.

If pkg_name is set, only list the given package. If version_req is set, filters with the given semver requirement. The given callback will be called for each version.