def test_init(self):
algebra = BooleanAlgebra()
self.assertRaises(TypeError, algebra.NOT)
self.assertRaises(TypeError, algebra.NOT, 'a', 'b')
algebra.NOT(algebra.Symbol('a'))
self.assertEqual(algebra.FALSE, (algebra.NOT(algebra.TRUE)).simplify())
self.assertEqual(algebra.TRUE, (algebra.NOT(algebra.FALSE)).simplify())
def test_parse_with_mixed_operators_multilines_and_custom_symbol(self):
class MySymbol(Symbol):
pass
expr_str = '''(a or ~ b +_c ) and
d & ( ! e_
| (my * g OR 1 or 0) ) AND that '''
algebra = BooleanAlgebra(Symbol_class=MySymbol)
expr = algebra.parse(expr_str)
expected = algebra.AND(
algebra.OR(
algebra.Symbol('a'),
algebra.NOT(algebra.Symbol('b')),
algebra.Symbol('_c'),
),
algebra.Symbol('d'),
algebra.OR(
algebra.NOT(algebra.Symbol('e_')),
algebra.OR(
algebra.AND(
algebra.Symbol('my'),
algebra.Symbol('g'),
),
algebra.TRUE,
algebra.FALSE,
),
),
algebra.Symbol('that'),
)
self.assertEqual(expected.pretty(), expr.pretty())
self.assertEqual(expected, expr)
def test_simplify_complex_expression_parsed_then_simplified(self):
# FIXME: THIS SHOULD NOT FAIL
algebra = BooleanAlgebra()
a = algebra.Symbol('a')
b = algebra.Symbol('b')
c = algebra.Symbol('c')
d = algebra.Symbol('d')
parse = algebra.parse
test_expression_str = ''.join('''
(~a&~b&~c&~d) | (~a&~b&~c&d) | (~a&b&~c&~d) |
(~a&b&c&d) | (~a&b&~c&d) | (~a&b&c&~d) |
(a&~b&~c&d) | (~a&b&c&d) | (a&~b&c&d) | (a&b&c&d)
'''.split())
test_expression = ((~a & ~b & ~c & ~d) | (~a & ~b & ~c & d) |
(~a & b & ~c & ~d) | (~a & b & c & d) |
(~a & b & ~c & d) | (~a & b & c & ~d) |
(a & ~b & ~c & d) | (~a & b & c & d) |
(a & ~b & c & d) | (a & b & c & d))
parsed = parse(test_expression_str)
self.assertEqual(test_expression_str, str(parsed))
expected = (a & ~b & d) | (~a & b) | (~a & ~c) | (b & c & d)
self.assertEqual(expected.pretty(),
test_expression.simplify().pretty())
parsed = parse(test_expression_str, simplify=True)
# FIXME: THIS SHOULD NOT FAIL
# we have a different simplify behavior for expressions built from python expressions
# vs. expression built from an object tree vs. expression built from a parse
self.assertEqual(expected.simplify().pretty(),
parsed.simplify().pretty())
expected_str = '(a&~b&d)|(~a&b)|(~a&~c)|(b&c&d)'
self.assertEqual(expected_str, str(parsed))
parsed2 = parse(test_expression_str)
self.assertEqual(expected.pretty(), parsed2.simplify().pretty())
self.assertEqual(expected_str, str(parsed2.simplify()))
expected = algebra.OR(
algebra.AND(algebra.NOT(algebra.Symbol('a')),
algebra.NOT(algebra.Symbol('b')),
algebra.NOT(algebra.Symbol('c')),
algebra.NOT(algebra.Symbol('d'))),
algebra.AND(algebra.NOT(algebra.Symbol('a')),
algebra.NOT(algebra.Symbol('b')),
algebra.NOT(algebra.Symbol('c')), algebra.Symbol('d')),
algebra.AND(algebra.NOT(algebra.Symbol('a')), algebra.Symbol('b'),
algebra.NOT(algebra.Symbol('c')),
algebra.NOT(algebra.Symbol('d'))),
algebra.AND(algebra.NOT(algebra.Symbol('a')), algebra.Symbol('b'),
algebra.Symbol('c'), algebra.Symbol('d')),
algebra.AND(algebra.NOT(algebra.Symbol('a')), algebra.Symbol('b'),
algebra.NOT(algebra.Symbol('c')), algebra.Symbol('d')),
algebra.AND(algebra.NOT(algebra.Symbol('a')), algebra.Symbol('b'),
algebra.Symbol('c'), algebra.NOT(algebra.Symbol('d'))),
algebra.AND(algebra.Symbol('a'), algebra.NOT(algebra.Symbol('b')),
algebra.NOT(algebra.Symbol('c')), algebra.Symbol('d')),
algebra.AND(algebra.NOT(algebra.Symbol('a')), algebra.Symbol('b'),
algebra.Symbol('c'), algebra.Symbol('d')),
algebra.AND(algebra.Symbol('a'), algebra.NOT(algebra.Symbol('b')),
algebra.Symbol('c'), algebra.Symbol('d')),
algebra.AND(algebra.Symbol('a'), algebra.Symbol('b'),
algebra.Symbol('c'), algebra.Symbol('d')))
result = parse(test_expression_str)
result = result.simplify()
self.assertEqual(expected, result)
def test_isliteral(self):
algebra = BooleanAlgebra()
s = algebra.Symbol(1)
self.assertTrue(algebra.NOT(s).isliteral)
self.assertFalse(algebra.parse('~(a|b)').isliteral)