Author Jim.Jewett
Recipients Jim.Jewett, catalin.iacob, eric.araujo, francescor, javawizard, lregebro, ncoghlan, python-dev, rhettinger
Date 2012-01-26.03:42:16
SpamBayes Score 1.26772e-06
Marked as misclassified No
Message-id <1327549338.33.0.506951268974.issue10042@psf.upfronthosting.co.za>
In-reply-to
Content
I like Nick Coghlan's suggestion in msg140493, but I think he was giving up too soon in the "or" cases, and I think the confusion could be slightly reduced by some re-spellings around return values and comments about short-circuiting.
   
def not_op(op, other):
    # "not a < b" handles "a >= b"
    # "not a <= b" handles "a > b"
    # "not a >= b" handles "a < b"
    # "not a > b" handles "a <= b"
    op_result = op(other)
    if op_result is NotImplemented:
        return NotImplemented
    return not op_result

def op_or_eq(op, self, other):
    # "a < b or a == b" handles "a <= b"
    # "a > b or a == b" handles "a >= b"
    op_result = op(other)
    if op_result is NotImplemented
        return self.__eq__(other) or NotImplemented
    if op_result:
        return True
    return self.__eq__(other)

def not_op_and_not_eq(op, self, other):
    # "not (a < b or a == b)" handles "a > b"
    # "not a < b and a != b" is equivalent
    # "not (a > b or a == b)" handles "a < b"
    # "not a > b and a != b" is equivalent
    op_result = op(other)
    if op_result is NotImplemented:
        return NotImplemented
    if op_result:
        return False
    return self.__ne__(other)

def not_op_or_eq(op, self, other):
    # "not a <= b or a == b" handles "a >= b"
    # "not a >= b or a == b" handles "a <= b"
    op_result = op(other)
    if op_result is NotImplemented:
        return self.__eq__(other) or NotImplemented
    if op_result:
        return self.__eq__(other)
    return True

def op_and_not_eq(op, self, other):
    # "a <= b and not a == b" handles "a < b"
    # "a >= b and not a == b" handles "a > b"
    op_result = op(other)
    if op_result is NotImplemented:
        return NotImplemented
    if op_result:
        return self.__ne__(other)
    return False
History
Date User Action Args
2012-01-26 03:42:18Jim.Jewettsetrecipients: + Jim.Jewett, rhettinger, ncoghlan, eric.araujo, lregebro, francescor, catalin.iacob, python-dev, javawizard
2012-01-26 03:42:18Jim.Jewettsetmessageid: <1327549338.33.0.506951268974.issue10042@psf.upfronthosting.co.za>
2012-01-26 03:42:17Jim.Jewettlinkissue10042 messages
2012-01-26 03:42:16Jim.Jewettcreate