def from_cfg(cls, cfg: CFG):
"""
Build RSA from a given cfpq_data context-free grammar
@param cfg: CFG on which RSA is built
@return: initialized class
"""
grammar = cfg.to_text()
productions = dict()
for line in grammar.split("\n")[:-1]:
part_line = line.split(" -> ")
right = part_line[1]
if right == "":
right = "epsilon"
if part_line[0] in productions:
productions[part_line[0]] += " | " + right
else:
productions[part_line[0]] = right
grammar_new = ""
for nonterminal in productions:
grammar_new += nonterminal + " -> " + productions[nonterminal] + "\n"
grammar_new = grammar_new[:-1]
return RecursiveAutomaton.from_rsm(rsm_from_text(grammar_new))
def test_rsm_from_and_to_txt(grammar):
(fd, fname) = tempfile.mkstemp()
rsm_1 = cfpq_data.rsm_from_text(grammar)
path = cfpq_data.rsm_to_txt(rsm_1, fname)
rsm_2 = cfpq_data.rsm_from_txt(path)
os.close(fd)
os.unlink(fname)
assert set(cfpq_data.rsm_to_text(rsm_1).splitlines()) == set(
cfpq_data.rsm_to_text(rsm_2).splitlines())
import pytest
import cfpq_data
cnf_1 = cfpq_data.cnf_from_text("S -> a S b | a b")
cnf_2 = cfpq_data.cnf_from_text(
"S -> sco_r S sco | t_r S t | sco_r sco | t_r t")
rsm_1 = cfpq_data.rsm_from_text("S -> a S b | a b")
rsm_2 = cfpq_data.rsm_from_text(
"S -> sco_r S sco | t_r S t | sco_r sco | t_r t")
@pytest.mark.parametrize("cnf", [cnf_1, cnf_2])
def test_cfg_from_cnf(cnf):
cfg = cfpq_data.cfg_from_cnf(cnf)
for word in cfg.get_words(4):
assert cfg.contains(word) and cnf.contains(word)
@pytest.mark.parametrize("rsm", [rsm_1, rsm_2])
def test_cfg_from_rsm(rsm):
cfg = cfpq_data.cfg_from_rsm(rsm)
for word in cfg.get_words(4):
assert cfg.contains(word) and rsm.contains(word)
import cfpq_data
cfg_1 = cfpq_data.cfg_from_text("S -> a S b S\nS -> a b\n")
exp_cfg_1 = cfpq_data.cfg_from_text("S -> b S c S\nS -> b c\n")
cfg_2 = cfpq_data.cfg_from_text("S -> a b c d\n")
exp_cfg_2 = cfpq_data.cfg_from_text("S -> b c c d\n")
cnf_1 = cfpq_data.cnf_from_text("S -> a")
exp_cnf_1 = cfpq_data.cnf_from_text("S -> b")
cnf_2 = cfpq_data.cnf_from_text("S -> b")
exp_cnf_2 = cfpq_data.cnf_from_text("S -> c")
rsm_1 = cfpq_data.rsm_from_text("S -> a b\n")
exp_rsm_1 = cfpq_data.rsm_from_text("S -> b c\n")
rsm_2 = cfpq_data.rsm_from_text("S -> b a\n")
exp_rsm_2 = cfpq_data.rsm_from_text("S -> c b\n")
@pytest.mark.parametrize(
"cfg, exp_cfg",
[
(cfg_1, exp_cfg_1),
(cfg_2, exp_cfg_2),
],
)
def test_change_terminals_in_cfg(cfg, exp_cfg):
act_cfg = cfpq_data.change_terminals_in_cfg(cfg, {"a": "b", "b": "c"})
def test_rsm_to_text(grammar, expected):
rsm = cfpq_data.rsm_from_text(grammar)
actual = set(cfpq_data.rsm_to_text(rsm).splitlines())
assert actual == expected
def test_rsm_from_text(grammar, expected):
rsm = cfpq_data.rsm_from_text(grammar)
for word in expected:
if word is not None:
assert rsm.contains(word)