42. Puzzle.__uniqueWordTest(): Require that a word
be used only once in the puzzle
kkck
# - - - P u z z l e . _ _ u n i q u e W o r d T e s t
def __uniqueWordTest ( self, slot ):
'''Find slots with one choice, and remove that choice from others
[ slot is a Slot in self ->
if slot has only one choice ->
remove that choice from all other slots
else -> I ]
'''
#-- 1 --
# [ slotChoiceList := list of all current choices for slot ]
slotChoiceList = [ word
for word in self.__wordBank.genSlotChoices(slot) ]
If there are multiple choices (or no choices), we are done: no
elimination can be performed. Otherwise, find the set of slots
that have that word, and eliminate it from the choices for those
slots. See Section 73, “WordBank.wordToSlots(): Which slots use a
given word?” and Section 68, “WordBank.isNot(): Remove one word from
a slot's list of choices”.
kkck
#-- 2 --
if len(slotChoiceList) != 1:
return
else:
word = slotChoiceList[0]
#-- 3 --
# [ otherSlotList := list of slots that use word,
# minus slot ]
otherSlotList = self.__wordBank.wordToSlots ( word )
otherSlotList.remove ( slot )
#-- 4 --
# [ self.__wordBank := self.__wordBank - (choices for
# slots in otherSlotList that equal word ]
for otherSlot in otherSlotList:
if VERBOSE:
print ( "*** Removing %s from %s because it goes in "
"%s." % (word, otherSlot, slot) )
self.__wordBank.isNot ( otherSlot, word )
