def test_oldStartSymbolShouldStaySame(self):
g = Grammar(nonterminals=[A], start_symbol=A)
self.assertIsNotNone(g.start)
with self.assertRaises(NonterminalDoesNotExistsException):
g.start = B
self.assertIsNotNone(g.start)
self.assertIs(g.start, A)
def test_shouldNotSetStartSymbol(self):
g = Grammar(nonterminals=[A, B])
self.assertIsNone(g.start)
with self.assertRaises(NotNonterminalException):
g.start = 'asdf'
self.assertIsNone(g.start)
self.assertFalse(g.start == 'asdf')
def test_oldStartSymbolShouldStaySame(self):
g = Grammar(nonterminals=[A, B], start_symbol=A)
self.assertIsNotNone(g.start)
self.assertIs(g.start, A)
with self.assertRaises(NotNonterminalException):
g.start = 'asdf'
self.assertIsNotNone(g.start)
self.assertIs(g.start, A)
def test_removeElementNotThere(self):
gr = Grammar()
gr.nonterminals.add(A, B, C)
self.assertEqual(gr.nonterminals.size(), 3)
self.assertEqual(len(gr.nonterminals), 3)
with self.assertRaises(KeyError):
gr.nonterminals.remove(D)
def test_removeEmptyGrammar(self):
gr = Grammar()
self.assertEqual(gr.nonterminals.size(), 0)
self.assertEqual(len(gr.nonterminals), 0)
gr.nonterminals.clear()
self.assertEqual(gr.nonterminals.size(), 0)
self.assertEqual(len(gr.nonterminals), 0)
def test_removeEmptyGrammar(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N])
self.assertEqual(gr.rules.size(), 0)
self.assertEqual(len(gr.rules), 0)
gr.nonterminals.clear()
self.assertEqual(gr.rules.size(), 0)
self.assertEqual(len(gr.rules), 0)
def test_removeOneOfTheElementNotThere(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N])
gr.rules.add(A, B, C)
self.assertEqual(gr.rules.size(), 3)
self.assertEqual(len(gr.rules), 3)
with self.assertRaises(KeyError):
gr.rules.remove(B, D)
def test_equalGetTermAndTermMethods(self):
gr = Grammar()
ins = TempClass()
gr.terminals.add(ins)
self.assertEqual(gr.terminals.size(), 1)
self.assertEqual(len(gr.terminals), 1)
self.assertIn(ins, gr.terminals)
def test_addSameTwiceInParameters(self):
gr = Grammar()
gr.nonterminals.add(A, B, A, C)
self.assertEqual(gr.nonterminals.size(), 3)
self.assertEqual(len(gr.nonterminals), 3)
self.assertIn(A, gr.nonterminals)
self.assertIn(B, gr.nonterminals)
self.assertIn(C, gr.nonterminals)
def test_addThreeAsArray(self):
gr = Grammar()
gr.nonterminals.add(*[A, B, C])
self.assertEqual(gr.nonterminals.size(), 3)
self.assertEqual(len(gr.nonterminals), 3)
self.assertIn(A, gr.nonterminals)
self.assertIn(B, gr.nonterminals)
self.assertIn(C, gr.nonterminals)
def test_addThreeAsArray(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N])
gr.rules.add(*[A, B, C])
self.assertEqual(gr.rules.size(), 3)
self.assertEqual(len(gr.rules), 3)
self.assertIn(A, gr.rules)
self.assertIn(B, gr.rules)
self.assertIn(C, gr.rules)
def test_addSameTwiceInParameters(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N])
gr.rules.add(A, B, A, C)
self.assertEqual(gr.rules.size(), 3)
self.assertEqual(len(gr.rules), 3)
self.assertIn(A, gr.rules)
self.assertIn(B, gr.rules)
self.assertIn(C, gr.rules)
def test_addInArray(self):
gr = Grammar()
gr.terminals.add(0, 'asdf', TempClass)
self.assertEqual(gr.terminals.size(), 3)
self.assertEqual(len(gr.terminals), 3)
self.assertIn(0, gr.terminals)
self.assertIn('asdf', gr.terminals)
self.assertIn(TempClass, gr.terminals)
def remove_rules_with_epsilon(grammar: Grammar,
transform_grammar=False) -> Grammar:
"""
Remove epsilon rules.
:param grammar: Grammar where rules remove
:param transform_grammar: True if transformation should be performed in place, false otherwise.
False by default.
:return: Grammar without epsilon rules.
"""
# Copy if required
if transform_grammar is False: grammar = copy(grammar)
# Find nonterminals rewritable to epsilon
rewritable = find_nonterminals_rewritable_to_epsilon(grammar)
# Create list from rules
rules = list(grammar.rules())
index = 0
# Iterate thought rules
while index < len(rules):
rule = rules[index]
index += 1
right = rule.right
if right == [EPSILON]:
if not grammar.start_isSet(
) or rule.fromSymbol != grammar.start_get():
grammar.remove_rule(rule)
# Continue IS executed, but due optimalization line is marked as missed.
continue #pragma: no cover
for rule_index in range(len(right)):
symbol = right[rule_index]
if symbol in rewritable:
new_rule = _create_rule(rule, rule_index, rewritable)
rules.append(new_rule)
grammar.add_rule(new_rule)
return grammar
def remove_nongenerating_nonterminals(grammar: Grammar,
transform_grammar=False) -> Grammar:
"""
Remove nongenerating symbols from the grammar
:param grammar: Grammar where to remove nongenerating symbols
:param transform_grammar: True if transformation should be performed in place, false otherwise.
False by default.
:return: Grammar without nongenerating symbols
"""
# Copy if required
if transform_grammar is False: grammar = copy(grammar)
# Create working sets
generates = set(item.s for item in grammar.terms())
generates.add(EPSILON)
rules = set(rule for rule in grammar.rules())
while True:
# Create set of next iteration
additional = generates.copy()
processedRules = []
# Iterate over unprocessed rules
for rule in rules:
rightPart = rule.right
allIn = True
# Check if all symbols on the right part of rule are in generates set
for symbol in rightPart:
if symbol not in generates:
allIn = False
break
# Symbol is missing so rule is not process
if not allIn: continue
# Rule is process - remove it from processing rules and make symbol as generating
additional.add(rule.fromSymbol)
processedRules.append(rule)
# End of rules iterations
# Remove process rules in current iteration
for item in processedRules:
rules.remove(item)
# If current and previous iterations are same, than end iterations
if additional == generates: break
# Swap sets from previous and current iterations
generates = additional
# Remove nonterms that are not generating
for nonterm in set(grammar.nonterms()).difference(generates):
grammar.remove_nonterm(nonterm)
return grammar
def test_unionUpdateOperator(self):
gr = Grammar(nonterminals=[B, C])
# Because Python is PIECE OF SHIT that can't handle F*****G OPERATOR on property
# if there isn't F*****G SETTER. Storing the property in variable na CALLING F*****G
# OPERATOR on that variable works and MODIFY F*****G PROPERTY ITSELF.
# Burn in F*****G HELL!!!!
nonterms = gr.nonterminals
with self.assertRaises(NotNonterminalException):
nonterms |= {A, B, 0}
def test_correctAddOne(self):
gr = Grammar()
self.assertEqual(gr.terminals.size(), 0)
self.assertEqual(len(gr.terminals), 0)
self.assertNotIn(0, gr.terminals)
gr.terminals.add(0)
self.assertEqual(gr.terminals.size(), 1)
self.assertEqual(len(gr.terminals), 1)
self.assertIn(0, gr.terminals)
def test_symDifferenceUpdateOperatorWithNotInside2(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N], rules=[B, C])
# Because Python is PIECE OF SHIT that can't handle F*****G OPERATOR on property
# if there isn't F*****G SETTER. Storing the property in variable na CALLING F*****G
# OPERATOR on that variable works and MODIFY F*****G PROPERTY ITSELF.
# Burn in F*****G HELL!!!!
rules = gr.rules
with self.assertRaises(NonterminalDoesNotExistsException):
rules ^= {A, B, NotInsideRule2}
def test_removeElementNotThere(self):
gr = Grammar(terminals=[0, 1, 2],
nonterminals=[N])
gr.rules.add(A, B, C)
self.assertEqual(gr.rules.size(), 3)
self.assertEqual(len(gr.rules), 3)
gr.rules.discard(D)
self.assertEqual(gr.rules.size(), 3)
self.assertEqual(len(gr.rules), 3)
def test_correctAddOne(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N])
self.assertEqual(gr.rules.size(), 0)
self.assertEqual(len(gr.rules), 0)
self.assertNotIn(A, gr.rules)
gr.rules.add(A)
self.assertEqual(gr.rules.size(), 1)
self.assertEqual(len(gr.rules), 1)
self.assertIn(A, gr.rules)
def test_intersectionUpdateOperatorWithInvalidRule(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N], rules=[A, B, C])
# Because Python is PIECE OF SHIT that can't handle F*****G OPERATOR on property
# if there isn't F*****G SETTER. Storing the property in variable na CALLING F*****G
# OPERATOR on that variable works and MODIFY F*****G PROPERTY ITSELF.
# Burn in F*****G HELL!!!!
rules = gr.rules
rules &= {B, C, 0, InvalidRule}
self.assertEqual(rules, {B, C})
self.assertEqual(gr.rules, {B, C})
def test_differenceUpdateOperator(self):
gr = Grammar(nonterminals=[A, B, C])
# Because Python is PIECE OF SHIT that can't handle F*****G OPERATOR on property
# if there isn't F*****G SETTER. Storing the property in variable na CALLING F*****G
# OPERATOR on that variable works and MODIFY F*****G PROPERTY ITSELF.
# Burn in F*****G HELL!!!!
nonterms = gr.nonterminals
nonterms -= {B, C}
self.assertEqual(nonterms, {A})
self.assertEqual(gr.nonterminals, {A})
def test_add_remove_add_one(self):
gr = Grammar()
self.assertEqual(len(gr.terminals), 0)
self.assertNotIn(0, gr.terminals)
gr.terminals.add(0)
self.assertEqual(len(gr.terminals), 1)
self.assertIn(0, gr.terminals)
gr.terminals.remove(0)
self.assertEqual(len(gr.terminals), 0)
self.assertNotIn(0, gr.terminals)
def test_unionUpdateOperator(self):
gr = Grammar(terminals=[0, 'asdf'])
# Because Python is PIECE OF SHIT that can't handle F*****G OPERATOR on property
# if there isn't F*****G SETTER. Storing the property in variable na CALLING F*****G
# OPERATOR on that variable works and MODIFY F*****G PROPERTY ITSELF.
# Burn in F*****G HELL!!!!
terms = gr.terminals
terms |= {'asdf', TempClass}
self.assertEqual(terms, {0, 'asdf', TempClass})
self.assertEqual(gr.terminals, {0, 'asdf', TempClass})
def test_addThreeOneDelete(self):
gr = Grammar(nonterminals=(A, B, C))
self.assertIn(A, gr.nonterminals)
self.assertIn(B, gr.nonterminals)
self.assertIn(C, gr.nonterminals)
self.assertNotIn(D, gr.nonterminals)
gr.nonterminals.remove(B)
self.assertIn(A, gr.nonterminals)
self.assertNotIn(B, gr.nonterminals)
self.assertIn(C, gr.nonterminals)
self.assertNotIn(D, gr.nonterminals)
def test_removeSameElementMoreTimesAsParameters(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N])
gr.rules.add(*[A, B, C])
self.assertEqual(gr.rules.size(), 3)
self.assertEqual(len(gr.rules), 3)
gr.rules.remove(B, B)
self.assertEqual(gr.rules.size(), 2)
self.assertEqual(len(gr.rules), 2)
self.assertIn(A, gr.rules)
self.assertNotIn(B, gr.rules)
self.assertIn(C, gr.rules)
def test_removeAll(self):
gr = Grammar()
gr.nonterminals.add(A, B, C)
self.assertEqual(gr.nonterminals.size(), 3)
self.assertEqual(len(gr.nonterminals), 3)
gr.nonterminals.clear()
self.assertEqual(gr.nonterminals.size(), 0)
self.assertEqual(len(gr.nonterminals), 0)
self.assertNotIn(A, gr.nonterminals)
self.assertNotIn(B, gr.nonterminals)
self.assertNotIn(C, gr.nonterminals)
def test_removeSameElementMoreTimesInArray(self):
gr = Grammar()
gr.terminals.add(*[0, 'asdf', TempClass])
self.assertEqual(gr.terminals.size(), 3)
self.assertEqual(len(gr.terminals), 3)
gr.terminals.remove(*[0, 0])
self.assertEqual(gr.terminals.size(), 2)
self.assertEqual(len(gr.terminals), 2)
self.assertNotIn(0, gr.terminals)
self.assertIn('asdf', gr.terminals)
self.assertIn(TempClass, gr.terminals)
def test_removeSameElementMoreTimesInArray(self):
gr = Grammar()
gr.nonterminals.add(*[A, B, C])
self.assertEqual(gr.nonterminals.size(), 3)
self.assertEqual(len(gr.nonterminals), 3)
gr.nonterminals.remove(*[B, B])
self.assertEqual(gr.nonterminals.size(), 2)
self.assertEqual(len(gr.nonterminals), 2)
self.assertIn(A, gr.nonterminals)
self.assertNotIn(B, gr.nonterminals)
self.assertIn(C, gr.nonterminals)
def test_addThreeOneDelete(self):
gr = Grammar(terminals=[0, 1, 2], nonterminals=[N], rules=(A, B, C))
self.assertIn(A, gr.rules)
self.assertIn(B, gr.rules)
self.assertIn(C, gr.rules)
self.assertNotIn(D, gr.rules)
gr.rules.remove(B)
self.assertIn(A, gr.rules)
self.assertNotIn(B, gr.rules)
self.assertIn(C, gr.rules)
self.assertNotIn(D, gr.rules)