Function walk 

pub fn walk(
    generator: &'static str,
    directory: &str,
) -> Result<Vec<SourceFile>, Error>

Parses every .rs file under directory (repository-relative), recursively.

Files whose stem is tests or ends in _tests are skipped: they are test modules, and the doubles in them implement the same public traits as the real thing.

Errors

Error::Io if the directory cannot be walked and Error::Unclassifiable if a file does not parse — a generator that reads a registry it cannot parse has no truth to report.