Package arrio exposes functions to manipulate records, exposing and using interfaces not unlike the ones defined in the stdlib io package.
Copy copies all the records available from src to dst. Copy returns the number of records copied and the first error encountered while copying, if any.
A successful Copy returns err == nil, not err == EOF. Because Copy is defined to read from src until EOF, it does not treat an EOF from Read as an error to be reported.
CopyN copies n records (or until an error) from src to dst. It returns the number of records copied and the earliest error encountered while copying. On return, written == n if and only if err == nil.
Reader is the interface that wraps the Read method.
ReaderAt is the interface that wraps the ReadAt method.
Writer is the interface that wraps the Write method.