--- self <=> other

    self  other  ASCII ɽӤơself 
    礭 0֤ޤ

    ѿ $= ͤǤӤϾ˥ե٥
    Ȥʸʸ̵뤷ƹԤޤ
    ($=ѿϤѻߤ뤳ȤˤʤäƤޤ obsolete 
    򻲾)

    ruby 1.8 feature:

    other ʸǤʤ硢other.to_str  
    other.<=> Ƥ 0 - (other <=> self) η
    ̤֤ޤǤʤ nil ֤ޤ

