def __init__(self, start_symbol, terminals=None):
'''Creates the syntax of some language which grammar is defined
by the calls to the methods of this class.
It is a high level view of the class Grammar which provides
a much more rich and high level expressions.
The parameters 'start_symbol' and 'terminals' are the same
parameters of the constructor of Grammar, but a difference of Grammar,
the 'start_symbol' is an required element.
See the documentation of Grammar.
'''
if start_symbol is None:
raise ValueError("The parameter 'start_symbol' must not be None.")
self._grammar = Grammar(start_symbol, terminals)
def __init__(self, start_symbol, terminals = None):
'''Creates the syntax of some language which grammar is defined
by the calls to the methods of this class.
It is a high level view of the class Grammar which provides
a much more rich and high level expressions.
The parameters 'start_symbol' and 'terminals' are the same
parameters of the constructor of Grammar, but a difference of Grammar,
the 'start_symbol' is an required element.
See the documentation of Grammar.
'''
if start_symbol is None:
raise ValueError("The parameter 'start_symbol' must not be None.")
self._grammar = Grammar(start_symbol, terminals)
def setUp(self):
self.simple = Grammar('A', ['a'])
self.simple.add_rule('A', ['M', 'a'])
self.simple.add_empty('M')
self.twolevels = Grammar('A', ['c'])
self.twolevels.add_rule('A', ['B', 'c'])
self.twolevels.add_rule('B', ['M'])
self.twolevels.add_empty('M')
self.no_empty = Grammar('A', ['a', 'd', 'c'])
self.no_empty.add_rule('A', ['B', 'a'])
self.no_empty.add_rule('B', ['d', 'C'])
self.no_empty.add_rule('C', ['c'])
self.follow_empty = Grammar('A', ['c', 'x'])
self.follow_empty.add_rule('A', ['B', 'c'])
self.follow_empty.add_rule('B', ['C', 'M'])
self.follow_empty.add_rule('C', ['x'])
self.follow_empty.add_empty('M')
def setUp(self):
self.simple = Grammar('S', ('a', 'b', 's'))
self.simple.add_rule('S', ('A', 'B', 's'))
self.simple.add_rule('A', ('a', 'A', 'A'))
self.simple.add_empty('A')
self.simple.add_rule('B', ('b', 'B', 'B'))
self.simple.add_empty('B')
self.lrvalue = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue.add_rule('S', ['L', '=', 'R'])
self.lrvalue.add_rule('S', ['R'])
self.lrvalue.add_rule('L', ['*', 'R'])
self.lrvalue.add_rule('L', ['id'])
self.lrvalue.add_rule('R', ['L'])
self.lrvalue.add_rule('R', ['(', 'S', ')'])
self.simple_terminal = Grammar('S', ('$',))
self.simple_terminal.add_rule('S', ['$'])
self.more_complex = Grammar('S', ['a', 'b', 'c', 'd', 'q', 'r'])
self.more_complex.add_rule('S', ['A', 'q'])
self.more_complex.add_rule('S', ['B', 'r'])
self.more_complex.add_rule('A', ['C', 'a'])
self.more_complex.add_empty('A')
self.more_complex.add_rule('B', ['D', 'b'])
self.more_complex.add_rule('C', ['c'])
self.more_complex.add_empty('C')
self.more_complex.add_rule('D', ['d'])
self.more_complex.add_empty('D')
self.left_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive.add_rule('E', ['E', '+', 'T'])
self.left_recursive.add_rule('E', ['E', '-', 'T'])
self.left_recursive.add_rule('E', ['T'])
self.left_recursive.add_rule('T', ['id'])
self.left_recursive.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive_epsilon.add_rule('E', ['E', '+', 'T'])
self.left_recursive_epsilon.add_rule('E', ['E', '-', 'T'])
self.left_recursive_epsilon.add_rule('E', ['T'])
self.left_recursive_epsilon.add_rule('T', ['id'])
self.left_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon.add_empty('T')
self.right_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive.add_rule('E', ['T', '+', 'E'])
self.right_recursive.add_rule('E', ['T', '-', 'E'])
self.right_recursive.add_rule('E', ['T'])
self.right_recursive.add_rule('T', ['id'])
self.right_recursive.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive_epsilon.add_rule('E', ['T', '+', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T', '-', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T'])
self.right_recursive_epsilon.add_rule('T', ['id'])
self.right_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon.add_empty('T')
self.lrvalue_with_actions = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue_with_actions.add_rule('S', ['L', '=', 'R', lambda args: 'assign', lambda args:args])
self.lrvalue_with_actions.add_rule('S', ['R'])
self.lrvalue_with_actions.add_rule('L', ['*', 'R', lambda args: 'deref', lambda args:args])
self.lrvalue_with_actions.add_rule('L', ['id'])
self.lrvalue_with_actions.add_rule('R', ['L'])
self.lrvalue_with_actions.add_rule('R', ['(', lambda args: 'push', 'S', lambda args: 'pop', ')', lambda args:args])
class FunctionalTestFollow(unittest.TestCase):
def setUp(self):
self.simple = Grammar('S', ('a', 'b', 's'))
self.simple.add_rule('S', ('A', 'B', 's'))
self.simple.add_rule('A', ('a', 'A', 'A'))
self.simple.add_empty('A')
self.simple.add_rule('B', ('b', 'B', 'B'))
self.simple.add_empty('B')
self.lrvalue = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue.add_rule('S', ['L', '=', 'R'])
self.lrvalue.add_rule('S', ['R'])
self.lrvalue.add_rule('L', ['*', 'R'])
self.lrvalue.add_rule('L', ['id'])
self.lrvalue.add_rule('R', ['L'])
self.lrvalue.add_rule('R', ['(', 'S', ')'])
self.simple_terminal = Grammar('S', ('$',))
self.simple_terminal.add_rule('S', ['$'])
self.more_complex = Grammar('S', ['a', 'b', 'c', 'd', 'q', 'r'])
self.more_complex.add_rule('S', ['A', 'q'])
self.more_complex.add_rule('S', ['B', 'r'])
self.more_complex.add_rule('A', ['C', 'a'])
self.more_complex.add_empty('A')
self.more_complex.add_rule('B', ['D', 'b'])
self.more_complex.add_rule('C', ['c'])
self.more_complex.add_empty('C')
self.more_complex.add_rule('D', ['d'])
self.more_complex.add_empty('D')
self.left_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive.add_rule('E', ['E', '+', 'T'])
self.left_recursive.add_rule('E', ['E', '-', 'T'])
self.left_recursive.add_rule('E', ['T'])
self.left_recursive.add_rule('T', ['id'])
self.left_recursive.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive_epsilon.add_rule('E', ['E', '+', 'T'])
self.left_recursive_epsilon.add_rule('E', ['E', '-', 'T'])
self.left_recursive_epsilon.add_rule('E', ['T'])
self.left_recursive_epsilon.add_rule('T', ['id'])
self.left_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon.add_empty('T')
self.right_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive.add_rule('E', ['T', '+', 'E'])
self.right_recursive.add_rule('E', ['T', '-', 'E'])
self.right_recursive.add_rule('E', ['T'])
self.right_recursive.add_rule('T', ['id'])
self.right_recursive.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive_epsilon.add_rule('E', ['T', '+', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T', '-', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T'])
self.right_recursive_epsilon.add_rule('T', ['id'])
self.right_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon.add_empty('T')
self.lrvalue_with_actions = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue_with_actions.add_rule('S', ['L', '=', 'R', lambda args: 'assign', lambda args:args])
self.lrvalue_with_actions.add_rule('S', ['R'])
self.lrvalue_with_actions.add_rule('L', ['*', 'R', lambda args: 'deref', lambda args:args])
self.lrvalue_with_actions.add_rule('L', ['id'])
self.lrvalue_with_actions.add_rule('R', ['L'])
self.lrvalue_with_actions.add_rule('R', ['(', lambda args: 'push', 'S', lambda args: 'pop', ')', lambda args:args])
def test_simple(self):
expected = follow(self.simple, 'A')
self.assertTrue(len(expected) == 3)
self.assertTrue('a' in expected)
self.assertTrue('b' in expected)
self.assertTrue('s' in expected)
expected = follow(self.simple, 'B')
self.assertTrue(len(expected) == 2)
self.assertTrue('b' in expected)
self.assertTrue('s' in expected)
expected = follow(self.simple, 'S')
self.assertTrue(len(expected) == 1)
self.assertTrue(self.simple.EOF in expected)
def test_lr_value(self):
expected = follow(self.lrvalue, 'S')
self.assertTrue(len(expected) == 2)
self.assertTrue(')' in expected)
self.assertTrue(self.lrvalue.EOF in expected)
expected = follow(self.lrvalue, 'L')
self.assertTrue(len(expected) == 3)
self.assertTrue(')' in expected)
self.assertTrue('=' in expected)
self.assertTrue(self.lrvalue.EOF in expected)
expected = follow(self.lrvalue, 'R')
self.assertTrue(len(expected) == 3)
self.assertTrue(')' in expected)
self.assertTrue('=' in expected)
self.assertTrue(self.lrvalue.EOF in expected)
def test_more_complex(self):
expected = follow(self.more_complex, 'A')
self.assertTrue(len(expected) == 1)
self.assertTrue('q' in expected)
expected = follow(self.more_complex, 'B')
self.assertTrue(len(expected) == 1)
self.assertTrue('r' in expected)
expected = follow(self.more_complex, 'S')
self.assertTrue(len(expected) == 1)
self.assertTrue(self.more_complex.EOF in expected)
expected = follow(self.more_complex, 'C')
self.assertTrue(len(expected) == 1)
self.assertTrue('a' in expected)
expected = follow(self.more_complex, 'D')
self.assertTrue(len(expected) == 1)
self.assertTrue('b' in expected)
def test_left_recursive(self):
expected = follow(self.left_recursive, 'T')
self.assertTrue(len(expected) == 4)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(')' in expected)
self.assertTrue(self.left_recursive.EOF in expected)
expected = follow(self.left_recursive, 'E')
self.assertTrue(len(expected) == 4)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(')' in expected)
self.assertTrue(self.left_recursive.EOF in expected)
def test_left_recursive_epsilon(self):
expected = follow(self.left_recursive_epsilon, 'T')
self.assertTrue(len(expected) == 4)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(')' in expected)
self.assertTrue(self.left_recursive_epsilon.EOF in expected)
expected = follow(self.left_recursive_epsilon, 'E')
self.assertTrue(len(expected) == 4)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(')' in expected)
self.assertTrue(self.left_recursive_epsilon.EOF in expected)
def test_right_recursive(self):
expected = follow(self.right_recursive, 'T')
self.assertTrue(len(expected) == 4)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(')' in expected)
self.assertTrue(self.right_recursive.EOF in expected)
expected = follow(self.right_recursive, 'E')
self.assertTrue(len(expected) == 2)
self.assertTrue(')' in expected)
self.assertTrue(self.right_recursive.EOF in expected)
def test_right_recursive_epsilon(self):
expected = follow(self.right_recursive_epsilon, 'T')
self.assertTrue(len(expected) == 4)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(')' in expected)
self.assertTrue(self.right_recursive_epsilon.EOF in expected)
expected = follow(self.right_recursive_epsilon, 'E')
self.assertTrue(len(expected) == 2)
self.assertTrue(')' in expected)
self.assertTrue(self.right_recursive_epsilon.EOF in expected)
def test_lr_value_with_actions(self):
expected = follow(self.lrvalue_with_actions, 'S')
self.assertTrue(len(expected) == 2)
self.assertTrue(')' in expected)
self.assertTrue(self.lrvalue_with_actions.EOF in expected)
expected = follow(self.lrvalue_with_actions, 'L')
self.assertTrue(len(expected) == 3)
self.assertTrue(')' in expected)
self.assertTrue('=' in expected)
self.assertTrue(self.lrvalue_with_actions.EOF in expected)
expected = follow(self.lrvalue_with_actions, 'R')
self.assertTrue(len(expected) == 3)
self.assertTrue(')' in expected)
self.assertTrue('=' in expected)
self.assertTrue(self.lrvalue_with_actions.EOF in expected)
def setUp(self):
self.simple = Grammar('S', ('a', 'b', 's'))
self.simple.add_rule('S', ('A', 'B', 's'))
self.simple.add_rule('A', ('a', 'A', 'A'))
self.simple.add_empty('A')
self.simple.add_rule('B', ('b', 'B', 'B'))
self.simple.add_empty('B')
self.lrvalue = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue.add_rule('S', ['L', '=', 'R'])
self.lrvalue.add_rule('S', ['R'])
self.lrvalue.add_rule('L', ['*', 'R'])
self.lrvalue.add_rule('L', ['id'])
self.lrvalue.add_rule('R', ['L'])
self.lrvalue.add_rule('R', ['(', 'S', ')'])
self.simple_terminal = Grammar('S', ('$', ))
self.simple_terminal.add_rule('S', ['$'])
self.more_complex = Grammar('S', ['a', 'b', 'c', 'd', 'q', 'r'])
self.more_complex.add_rule('S', ['A', 'q'])
self.more_complex.add_rule('S', ['B', 'r'])
self.more_complex.add_rule('A', ['C', 'a'])
self.more_complex.add_empty('A')
self.more_complex.add_rule('B', ['D', 'b'])
self.more_complex.add_rule('C', ['c'])
self.more_complex.add_empty('C')
self.more_complex.add_rule('D', ['d'])
self.more_complex.add_empty('D')
self.left_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive.add_rule('E', ['E', '+', 'T'])
self.left_recursive.add_rule('E', ['E', '-', 'T'])
self.left_recursive.add_rule('E', ['T'])
self.left_recursive.add_rule('T', ['id'])
self.left_recursive.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive_epsilon.add_rule('E', ['E', '+', 'T'])
self.left_recursive_epsilon.add_rule('E', ['E', '-', 'T'])
self.left_recursive_epsilon.add_rule('E', ['T'])
self.left_recursive_epsilon.add_rule('T', ['id'])
self.left_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon.add_empty('T')
self.right_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive.add_rule('E', ['T', '+', 'E'])
self.right_recursive.add_rule('E', ['T', '-', 'E'])
self.right_recursive.add_rule('E', ['T'])
self.right_recursive.add_rule('T', ['id'])
self.right_recursive.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive_epsilon.add_rule('E', ['T', '+', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T', '-', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T'])
self.right_recursive_epsilon.add_rule('T', ['id'])
self.right_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon.add_empty('T')
self.lrvalue_with_actions = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue_with_actions.add_rule(
'S', ['L', '=', 'R', lambda args: 'assign', lambda args: args])
self.lrvalue_with_actions.add_rule('S', ['R'])
self.lrvalue_with_actions.add_rule(
'L', ['*', 'R', lambda args: 'deref', lambda args: args])
self.lrvalue_with_actions.add_rule('L', ['id'])
self.lrvalue_with_actions.add_rule('R', ['L'])
self.lrvalue_with_actions.add_rule('R', [
'(', lambda args: 'push', 'S', lambda args: 'pop', ')',
lambda args: args
])
class FunctionalTestFirst(unittest.TestCase):
def setUp(self):
self.simple = Grammar('S', ('a', 'b', 's'))
self.simple.add_rule('S', ('A', 'B', 's'))
self.simple.add_rule('A', ('a', 'A', 'A'))
self.simple.add_empty('A')
self.simple.add_rule('B', ('b', 'B', 'B'))
self.simple.add_empty('B')
self.lrvalue = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue.add_rule('S', ['L', '=', 'R'])
self.lrvalue.add_rule('S', ['R'])
self.lrvalue.add_rule('L', ['*', 'R'])
self.lrvalue.add_rule('L', ['id'])
self.lrvalue.add_rule('R', ['L'])
self.lrvalue.add_rule('R', ['(', 'S', ')'])
self.simple_terminal = Grammar('S', ('$', ))
self.simple_terminal.add_rule('S', ['$'])
self.more_complex = Grammar('S', ['a', 'b', 'c', 'd', 'q', 'r'])
self.more_complex.add_rule('S', ['A', 'q'])
self.more_complex.add_rule('S', ['B', 'r'])
self.more_complex.add_rule('A', ['C', 'a'])
self.more_complex.add_empty('A')
self.more_complex.add_rule('B', ['D', 'b'])
self.more_complex.add_rule('C', ['c'])
self.more_complex.add_empty('C')
self.more_complex.add_rule('D', ['d'])
self.more_complex.add_empty('D')
self.left_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive.add_rule('E', ['E', '+', 'T'])
self.left_recursive.add_rule('E', ['E', '-', 'T'])
self.left_recursive.add_rule('E', ['T'])
self.left_recursive.add_rule('T', ['id'])
self.left_recursive.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.left_recursive_epsilon.add_rule('E', ['E', '+', 'T'])
self.left_recursive_epsilon.add_rule('E', ['E', '-', 'T'])
self.left_recursive_epsilon.add_rule('E', ['T'])
self.left_recursive_epsilon.add_rule('T', ['id'])
self.left_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.left_recursive_epsilon.add_empty('T')
self.right_recursive = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive.add_rule('E', ['T', '+', 'E'])
self.right_recursive.add_rule('E', ['T', '-', 'E'])
self.right_recursive.add_rule('E', ['T'])
self.right_recursive.add_rule('T', ['id'])
self.right_recursive.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon = Grammar('E', ('+', '-', 'id', '(', ')'))
self.right_recursive_epsilon.add_rule('E', ['T', '+', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T', '-', 'E'])
self.right_recursive_epsilon.add_rule('E', ['T'])
self.right_recursive_epsilon.add_rule('T', ['id'])
self.right_recursive_epsilon.add_rule('T', ['(', 'E', ')'])
self.right_recursive_epsilon.add_empty('T')
self.lrvalue_with_actions = Grammar('S', ('=', '*', '(', ')', 'id'))
self.lrvalue_with_actions.add_rule(
'S', ['L', '=', 'R', lambda args: 'assign', lambda args: args])
self.lrvalue_with_actions.add_rule('S', ['R'])
self.lrvalue_with_actions.add_rule(
'L', ['*', 'R', lambda args: 'deref', lambda args: args])
self.lrvalue_with_actions.add_rule('L', ['id'])
self.lrvalue_with_actions.add_rule('R', ['L'])
self.lrvalue_with_actions.add_rule('R', [
'(', lambda args: 'push', 'S', lambda args: 'pop', ')',
lambda args: args
])
def test_simple(self):
expected = first(self.simple, ['A'])
self.assertTrue(len(expected) == 2)
self.assertTrue('a' in expected)
self.assertTrue(self.simple.EMPTY in expected)
expected = first(self.simple, ['B'])
self.assertTrue(len(expected) == 2)
self.assertTrue('b' in expected)
self.assertTrue(self.simple.EMPTY in expected)
expected = first(self.simple, ['S'])
self.assertTrue(len(expected) == 3)
self.assertTrue('s' in expected)
self.assertTrue('b' in expected)
self.assertTrue('a' in expected)
def test_lr_value(self):
expected = first(self.lrvalue, ['S'])
self.assertTrue(len(expected) == 3)
self.assertTrue('(' in expected)
self.assertTrue('*' in expected)
self.assertTrue('id' in expected)
expected = first(self.lrvalue, ['L'])
self.assertTrue(len(expected) == 2)
self.assertTrue('*' in expected)
self.assertTrue('id' in expected)
expected = first(self.lrvalue, ['R'])
self.assertTrue(len(expected) == 3)
self.assertTrue('(' in expected)
self.assertTrue('*' in expected)
self.assertTrue('id' in expected)
def test_more_complex(self):
expected = first(self.more_complex, ['A'])
self.assertTrue(len(expected) == 3)
self.assertTrue('a' in expected)
self.assertTrue('c' in expected)
self.assertTrue(self.more_complex.EMPTY in expected)
expected = first(self.more_complex, ['B'])
self.assertTrue(len(expected) == 2)
self.assertTrue('d' in expected)
self.assertTrue('b' in expected)
expected = first(self.more_complex, ['S'])
self.assertTrue(len(expected) == 5)
self.assertTrue('d' in expected)
self.assertTrue('b' in expected)
self.assertTrue('a' in expected)
self.assertTrue('c' in expected)
self.assertTrue('q' in expected)
def test_left_recursive(self):
expected = first(self.left_recursive, ['T'])
self.assertTrue(len(expected) == 2)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
expected = first(self.left_recursive, ['E'])
self.assertTrue(len(expected) == 2)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
def test_left_recursive_epsilon(self):
expected = first(self.left_recursive_epsilon, ['T'])
self.assertTrue(len(expected) == 3)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
self.assertTrue(self.left_recursive_epsilon.EMPTY in expected)
expected = first(self.left_recursive_epsilon, ['E'])
self.assertTrue(len(expected) == 5)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(self.left_recursive_epsilon.EMPTY in expected)
def test_right_recursive(self):
expected = first(self.right_recursive, ['T'])
self.assertTrue(len(expected) == 2)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
expected = first(self.right_recursive, ['E'])
self.assertTrue(len(expected) == 2)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
def test_right_recursive_epsilon(self):
expected = first(self.right_recursive_epsilon, ['T'])
self.assertTrue(len(expected) == 3)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
self.assertTrue(self.right_recursive_epsilon.EMPTY in expected)
expected = first(self.right_recursive_epsilon, ['E'])
self.assertTrue(len(expected) == 5)
self.assertTrue('id' in expected)
self.assertTrue('(' in expected)
self.assertTrue('+' in expected)
self.assertTrue('-' in expected)
self.assertTrue(self.right_recursive_epsilon.EMPTY in expected)
def test_lr_value_with_actions(self):
expected = first(self.lrvalue_with_actions, ['S'])
self.assertTrue(len(expected) == 3)
self.assertTrue('(' in expected)
self.assertTrue('*' in expected)
self.assertTrue('id' in expected)
expected = first(self.lrvalue_with_actions, ['L'])
self.assertTrue(len(expected) == 2)
self.assertTrue('*' in expected)
self.assertTrue('id' in expected)
expected = first(self.lrvalue_with_actions, ['R'])
self.assertTrue(len(expected) == 3)
self.assertTrue('(' in expected)
self.assertTrue('*' in expected)
self.assertTrue('id' in expected)
class Syntax(object):
'''See the __init__ method.'''
def __init__(self, start_symbol, terminals=None):
'''Creates the syntax of some language which grammar is defined
by the calls to the methods of this class.
It is a high level view of the class Grammar which provides
a much more rich and high level expressions.
The parameters 'start_symbol' and 'terminals' are the same
parameters of the constructor of Grammar, but a difference of Grammar,
the 'start_symbol' is an required element.
See the documentation of Grammar.
'''
if start_symbol is None:
raise ValueError("The parameter 'start_symbol' must not be None.")
self._grammar = Grammar(start_symbol, terminals)
@staticmethod
def _symbols(symbols, sym_production=None):
'''Utility to make 'symbols' a tuple, concatenated with 'sym_production'
if it is not None.
'''
if not isinstance(symbols, (list, tuple)):
symbols = (str(symbols), )
if sym_production:
return tuple(symbols) + (sym_production, )
else:
return tuple(symbols)
def terminal(self, terminal, _unused):
'''Adds a terminal element.
See the documentation of 'add_terminal' of Grammar.
'''
self._grammar.add_terminal(terminal)
return terminal
def rule(self, symbols, production_name):
'''Adds a rule 'production_name' -> 'symbols'.
See the documentation of 'add_production' of Grammar.
'''
self._grammar.add_rule(production_name, self._symbols(symbols))
return production_name
def choice(self, alternatives, production_name):
'''Adds multiples rules, each rule assigned to the same 'production_name'
symbol, making each one a possible alternative.
See the documentation of 'add_rule' of Grammar.
'''
if len(alternatives) <= 1:
raise ValueError('''Expected two or more alternatives,
but received '%s'.''' % str(alternatives))
for alternative in alternatives:
self._grammar.add_rule(production_name, self._symbols(alternative))
return production_name
def repeat(self, symbols, production_name):
'''Adds a high level rule which derivates in "one or more" times
the 'production_name' symbol.'''
self._grammar.add_rule(production_name,
self._symbols(symbols, production_name))
self._grammar.add_rule(production_name, self._symbols(symbols))
return production_name
def optional(self, symbols, production_name):
'''Adds a high level rule which derivates in "zero or one" times
the 'production_name' symbol.'''
self._grammar.add_rule(production_name, self._symbols(symbols))
self._grammar.add_empty(production_name)
return production_name
def as_grammar(self):
'''Returns a grammar.'''
return self._grammar
class FunctionalTestSpecial(unittest.TestCase):
def setUp(self):
self.simple = Grammar('A', ['a'])
self.simple.add_rule('A', ['M', 'a'])
self.simple.add_empty('M')
self.twolevels = Grammar('A', ['c'])
self.twolevels.add_rule('A', ['B', 'c'])
self.twolevels.add_rule('B', ['M'])
self.twolevels.add_empty('M')
self.no_empty = Grammar('A', ['a', 'd', 'c'])
self.no_empty.add_rule('A', ['B', 'a'])
self.no_empty.add_rule('B', ['d', 'C'])
self.no_empty.add_rule('C', ['c'])
self.follow_empty = Grammar('A', ['c', 'x'])
self.follow_empty.add_rule('A', ['B', 'c'])
self.follow_empty.add_rule('B', ['C', 'M'])
self.follow_empty.add_rule('C', ['x'])
self.follow_empty.add_empty('M')
def test_functions_simple_grammar(self):
expected = first(self.simple, ['A'])
self.assertTrue(len(expected) == 1)
self.assertTrue('a' in expected)
expected = follow(self.simple, 'M')
self.assertTrue(len(expected) == 1)
self.assertTrue('a' in expected)
def test_functions_twolevels_grammar(self):
expected = first(self.twolevels, ['A'])
self.assertTrue(len(expected) == 1)
self.assertTrue('c' in expected)
expected = first(self.twolevels, ['B'])
self.assertTrue(len(expected) == 1)
self.assertTrue(self.twolevels.EMPTY in expected)
expected = follow(self.twolevels, 'B')
self.assertTrue(len(expected) == 1)
self.assertTrue('c' in expected)
expected = follow(self.twolevels, 'M')
self.assertTrue(expected == follow(self.twolevels, 'B'))
def test_functions_no_empty_grammar(self):
expected = follow(self.no_empty, 'B')
self.assertTrue(len(expected) == 1)
self.assertTrue('a' in expected)
expected = follow(self.no_empty, 'C')
self.assertTrue(expected == follow(self.no_empty, 'B'))
def test_functions_follow_empty(self):
expected = follow(self.follow_empty, 'B')
self.assertTrue(len(expected) == 1)
self.assertTrue('c' in expected)
expected = follow(self.follow_empty, 'C')
self.assertTrue(expected == follow(self.follow_empty, 'B'))
class Syntax(object):
'''See the __init__ method.'''
def __init__(self, start_symbol, terminals = None):
'''Creates the syntax of some language which grammar is defined
by the calls to the methods of this class.
It is a high level view of the class Grammar which provides
a much more rich and high level expressions.
The parameters 'start_symbol' and 'terminals' are the same
parameters of the constructor of Grammar, but a difference of Grammar,
the 'start_symbol' is an required element.
See the documentation of Grammar.
'''
if start_symbol is None:
raise ValueError("The parameter 'start_symbol' must not be None.")
self._grammar = Grammar(start_symbol, terminals)
@staticmethod
def _symbols(symbols, sym_production=None):
'''Utility to make 'symbols' a tuple, concatenated with 'sym_production'
if it is not None.
'''
if not isinstance(symbols, (list, tuple)):
symbols = (str(symbols), )
if sym_production:
return tuple(symbols)+(sym_production,)
else:
return tuple(symbols)
def terminal(self, terminal, _unused):
'''Adds a terminal element.
See the documentation of 'add_terminal' of Grammar.
'''
self._grammar.add_terminal(terminal)
return terminal
def rule(self, symbols, production_name):
'''Adds a rule 'production_name' -> 'symbols'.
See the documentation of 'add_production' of Grammar.
'''
self._grammar.add_rule(production_name, self._symbols(symbols))
return production_name
def choice(self, alternatives, production_name):
'''Adds multiples rules, each rule assigned to the same 'production_name'
symbol, making each one a possible alternative.
See the documentation of 'add_rule' of Grammar.
'''
if len(alternatives) <= 1:
raise ValueError('''Expected two or more alternatives,
but received '%s'.''' % str(alternatives))
for alternative in alternatives:
self._grammar.add_rule(production_name,
self._symbols(alternative))
return production_name
def repeat(self, symbols, production_name):
'''Adds a high level rule which derivates in "one or more" times
the 'production_name' symbol.'''
self._grammar.add_rule(production_name,
self._symbols(symbols, production_name))
self._grammar.add_rule(production_name,
self._symbols(symbols))
return production_name
def optional(self, symbols, production_name):
'''Adds a high level rule which derivates in "zero or one" times
the 'production_name' symbol.'''
self._grammar.add_rule(production_name, self._symbols(symbols))
self._grammar.add_empty(production_name)
return production_name
def as_grammar(self):
'''Returns a grammar.'''
return self._grammar
