Ruby 1.8.7 リファレンスマニュアル > ライブラリ一覧 > net/imapライブラリ > Net::IMAPクラス > thread
thread(algorithm, search_keys, charset)
As for #search(), but returns message sequence numbers in threaded format, as a Net::IMAP::ThreadMember tree. The supported algorithms are:
ORDEREDSUBJECT:: split into single-level threads according to subject,
ordered by date.
REFERENCES:: split into threads by parent/child relationships determined
by which message is a reply to which.
Unlike #search(), +charset+ is a required argument. US-ASCII and UTF-8 are sample values.
See [SORT-THREAD-EXT] for more details.