--- grep(pattern)
--- grep(pattern) {|item| ... }

    pattern === item ΩǤƴޤ֤
    ޤ֥åȤȤ˸ƤӽФ줿ˤϾΩǤФ
    줾֥åɾη̤֤ޤޥå
    ҤȤĤʤä϶֤ޤ

