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 __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('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
])
