Python epsilon Examples

Example #1

File: fsm_test.py Project: xwzacker/python2-regex-and-fsm

def test_derive(a, b):
    # Just some basic tests because this is mainly a regex thing.
    assert a.derive("a") == epsilon({"a", "b"})
    assert a.derive("b") == null({"a", "b"})
    try:
        a.derive("c")
        assert False
    except KeyError:
        assert True
    assert (a * 3).derive("a") == a * 2
    assert (a.star() - epsilon({"a", "b"})).derive("a") == a.star()

Example #2

File: fsm_test.py Project: FakerKimg/python2-regex-and-fsm

def test_derive(a, b):
	# Just some basic tests because this is mainly a regex thing.
	assert a.derive("a") == epsilon({"a", "b"})
	assert a.derive("b") == null({"a", "b"})
	try:
		a.derive("c")
		assert False
	except KeyError:
		assert True
	assert (a * 3).derive("a") == a * 2
	assert (a.star() - epsilon({"a", "b"})).derive("a") == a.star()

Example #3

File: lego.py Project: AdeebNqo/sublimegen

	def fsm(self, alphabet=None):
		from greenery.fsm import epsilon

		if alphabet is None:
			alphabet = self.alphabet()

		# worked example: (min, max) = (5, 7) or (5, inf)
		# (mandatory, optional) = (5, 2) or (5, inf)

		unit = self.multiplicand.fsm(alphabet)
		# accepts e.g. "ab"

		# accepts "ababababab"
		mandatory = unit * self.multiplier.mandatory.v

		# unlimited additional copies
		if self.multiplier.optional == inf:
			optional = unit.star()
			# accepts "(ab)*"

		else:
			optional = epsilon(alphabet) | unit
			# accepts "(ab)?"

			optional *= self.multiplier.optional.v
			# accepts "(ab)?(ab)?"

		return mandatory + optional

Example #4

File: lego.py Project: AdeebNqo/sublimegen

	def fsm(self, alphabet=None):
		from greenery.fsm import epsilon

		if alphabet is None:
			alphabet = self.alphabet()

		# start with a component accepting only the empty string
		fsm1 = epsilon(alphabet)
		for m in self.mults:
			fsm1 += m.fsm(alphabet)
		return fsm1

Example #5

File: fsm_test.py Project: lnerit/greenery

def test_concatenation_aa(a):
	concAA = a + a
	assert not concAA.accepts("")
	assert not concAA.accepts("a")
	assert concAA.accepts("aa")
	assert not concAA.accepts("aaa")

	concAA = epsilon({"a", "b"}) + a + a
	assert not concAA.accepts("")
	assert not concAA.accepts("a")
	assert concAA.accepts("aa")
	assert not concAA.accepts("aaa")

Example #6

File: fsm_test.py Project: xwzacker/python2-regex-and-fsm

def test_concatenation_aa(a):
    concAA = a + a
    assert not concAA.accepts("")
    assert not concAA.accepts("a")
    assert concAA.accepts("aa")
    assert not concAA.accepts("aaa")

    concAA = epsilon({"a", "b"}) + a + a
    assert not concAA.accepts("")
    assert not concAA.accepts("a")
    assert concAA.accepts("aa")
    assert not concAA.accepts("aaa")

Example #7

File: fsm_test.py Project: lnerit/greenery

def test_optional_mul(a, b):
	unit = a + b
	# accepts "ab"

	optional = (epsilon(a.alphabet) | unit)
	# accepts "(ab)?
	assert optional.accepts([])
	assert not optional.accepts(["a"])
	assert not optional.accepts(["b"])
	assert optional.accepts(["a", "b"])
	assert not optional.accepts(["a", "a"])

	optional = optional * 2
	# accepts "(ab)?(ab)?"
	assert optional.accepts([])
	assert not optional.accepts(["a"])
	assert not optional.accepts(["b"])
	assert not optional.accepts(["a", "a"])
	assert optional.accepts(["a", "b"])
	assert not optional.accepts(["b", "a"])
	assert not optional.accepts(["b", "b"])
	assert not optional.accepts(["a", "a", "a"])
	assert optional.accepts(["a", "b", "a", "b"])

Example #8

File: fsm_test.py Project: xwzacker/python2-regex-and-fsm

def test_optional_mul(a, b):
    unit = a + b
    # accepts "ab"

    optional = (epsilon(a.alphabet) | unit)
    # accepts "(ab)?
    assert optional.accepts([])
    assert not optional.accepts(["a"])
    assert not optional.accepts(["b"])
    assert optional.accepts(["a", "b"])
    assert not optional.accepts(["a", "a"])

    optional = optional * 2
    # accepts "(ab)?(ab)?"
    assert optional.accepts([])
    assert not optional.accepts(["a"])
    assert not optional.accepts(["b"])
    assert not optional.accepts(["a", "a"])
    assert optional.accepts(["a", "b"])
    assert not optional.accepts(["b", "a"])
    assert not optional.accepts(["b", "b"])
    assert not optional.accepts(["a", "a", "a"])
    assert optional.accepts(["a", "b", "a", "b"])

Example #9

File: fsm_test.py Project: lnerit/greenery

def test_concatenate_bug(a):
	# This exposes a defect in fsm.concatenate.
	assert fsm.concatenate(a, epsilon({"a"}), a).accepts("aa")
	assert fsm.concatenate(a, epsilon({"a"}), epsilon({"a"}), a).accepts("aa")

Example #10

File: fsm_test.py Project: lnerit/greenery

def test_builtins():
	assert not null("a").accepts("a")
	assert epsilon("a").accepts("")
	assert not epsilon("a").accepts("a")

Example #11

File: fsm_test.py Project: lnerit/greenery

def test_reverse_epsilon():
	# epsilon reversed is epsilon
	assert reversed(epsilon("a")).accepts("")

Example #12

File: fsm_test.py Project: xwzacker/python2-regex-and-fsm

def test_concatenate_bug(a):
    # This exposes a defect in fsm.concatenate.
    assert fsm.concatenate(a, epsilon({"a"}), a).accepts("aa")
    assert fsm.concatenate(a, epsilon({"a"}), epsilon({"a"}), a).accepts("aa")

Example #13

File: fsm_test.py Project: xwzacker/python2-regex-and-fsm

def test_builtins():
    assert not null("a").accepts("a")
    assert epsilon("a").accepts("")
    assert not epsilon("a").accepts("a")

Example #14

File: fsm_test.py Project: xwzacker/python2-regex-and-fsm

def test_reverse_epsilon():
    # epsilon reversed is epsilon
    assert reversed(epsilon("a")).accepts("")

Example #15

 def to_fsm(self, alphabet=None, prefix_postfix=None, flags=None) -> FSM:
     if alphabet is None:
         alphabet = self.alphabet
     return epsilon(alphabet)