huey: Internal maintenance specification

This method takes two arguments. The goodName argument is a color name; badName is a less-preferred alternative.

# - - -   P i c k L i s t . _ _ p u r g e N a m e

    def __purgeName ( self, goodName, badName ):
        """If badName is redundant for goodName, remove it.

          [ (goodName is a color name in self.__colorMap) and
            (badName is a string) ->
              if  goodName == badName ->
                I
                else if  badName is a color name in self.__colorMap
                that is the same color as self.__colorMap[goodName] ->
                self.__colorMap  :=  self.__colorName with its
                    entry for badName removed
              else -> I ]              
        """

First we test to see if goodName and badName are the same. For example, the .__lowerize() transformation on "red" yields "red". In this case we return.

        #-- 1 --
        if  goodName == badName:
            return

Next, test to see if badName is even in the color map. If not, return. If it is there, retrieve the colors for both names.

        #-- 2 --
        # [ if  badName is a key in self.__colorMap ->
        #     goodColor  :=  self's color for goodName
        #     badColor   :=  self's color for badName
        #   else ->
        #     return ]
        badColor  =  self.lookupName ( badName )
        if  badColor is None:
            return
        else:
            goodColor  =  self.lookupName ( goodName )

If the colors are the same, we can safely remove the less preferred one. If they don't match, just for safety, retain the bad color.

        #-- 3 --
        # [ if  badColor == goodColor ->
        #     self.__colorMap  :=  self.__colorMap with the entry
        #         for badColor removed
        #   else -> I ]
        if  badColor == goodColor:
            badKey  =  badName.upper()
            del  self.__colorMap [ badKey ]