def test_grammar_recognition4():
grammar = """
SS->SS|a
"""
g = Grammar.from_string(grammar)
assert len(g.rules) == 2
assert g.get_init_nterm() == 'SS'
def test_grammar_recognition1():
grammar = """
S->a
S->b|c
"""
g = Grammar.from_string(grammar)
assert len(g.rules) == 3
assert g.get_init_nterm() == 'S'
def test_grammar_recognition2():
grammar = """
WORD->abSYM
SYM->b|c|$
"""
g = Grammar.from_string(grammar)
assert len(g.rules) == 4
assert g.get_init_nterm() == 'WORD'
def test_grammar_recognition5():
grammar = """
A -> aaaaa|a|a|bb bbb |B
B->&
"""
g = Grammar.from_string(grammar)
assert len(g.rules) == 6
assert g.get_init_nterm() == 'A'
assert len(g._alphabet) == 3
