Package gbytes provides a buffer that supports incrementally detecting input.
You use gbytes.Buffer with the gbytes.Say matcher. When Say finds a match, it fastforwards the buffer's read cursor to the end of that match.
Subsequent matches against the buffer will only operate against data that appears *after* the read cursor.
The read cursor is an opaque implementation detail that you cannot access. You should use the Say matcher to sift through the buffer. You can always access the entire buffer's contents with Contents().