from geniusweb.issuevalue.Bid import Bid
from geniusweb.profile.Profile import Profile

class PartialOrdering( Profile ):
	'''
	Defines a is-better relation between bids. This basically is a partially
	ordered space however some bids or groups of bids may not be relatable to
	others.
	'''
	def isPreferredOrEqual(self, bid1:Bid , bid2:Bid ) -> bool:
		'''
		@param bid1 the first item's utility/preference
		@param bid2 the second item's utility/preference
		@return true iff bid1 is considered better or equal (≥) than bid 2. In
		        all other cases false is returned. A bid may not have a ≥
		        relation at all.
		
		        This predicate should be implemented such that
		        <ul>
		        <li>b &ge; b (every bid is better or equal to itself)
		        <li>If b1&ge;b2 and b2&ge;b1 then the two bids are considered
		        equally good. Note that this differes from a partial order in
		        mathematics.
		        <li>it behaves transitive: if b1&ge;b2 and b2&ge;b3 then
		        b1&ge;b3.
		        </ul>
		'''