class TestLookAheadBasics:
def setup_method(self, method):
self.parser = Parser()
self.tok1 = self.parser.Token_n("t1", 'foo')
self.tok2 = self.parser.Token_n("t2", 'bar')
self.tok3 = self.parser.Token_n("t3", 'foobar')
self.tokens = [self.tok1, self.tok2, self.tok3]
self.parser.build_first_sets()
def test_basic_token(self):
assert self.tok1.first_set == [self.tok1]
def test_basic_alternative(self):
alt = self.parser.Alternative_n("a1t", self.tokens)
self.parser.build_first_sets()
assert alt.first_set == self.tokens
def test_basic_sequence(self):
seq = self.parser.Sequence_n("seq", self.tokens)
self.parser.build_first_sets()
assert seq.first_set == [self.tokens[0]]
def test_basic_kleenstar(self):
tok1, tok2, tok3 = self.tokens
kstar1 = self.parser.KleeneStar_n("k", 1, 3, tok1)
kstar2 = self.parser.KleeneStar_n("k2", 0, 3, tok1)
self.parser.build_first_sets()
assert kstar1.first_set == [tok1]
assert kstar2.first_set == [tok1, self.parser.EmptyToken]
def test_maybe_empty_sequence(self):
"""S -> tok1{0,2} tok2{0,2}
==> S.first_set = [tok1, tok2, EmptyToken]
"""
tok1, tok2, tok3 = self.tokens
k1 = self.parser.KleeneStar_n( "k1", 0, 2, tok1)
k2 = self.parser.KleeneStar_n("k2", 0, 2, tok2)
seq = self.parser.Sequence_n( "seq", [k1, k2])
self.parser.build_first_sets()
assert seq.first_set == [tok1, tok2, self.parser.EmptyToken]
def test_not_empty_sequence(self):
"""S -> tok1{0,2} tok2{1,2}
==> S.first_set = [tok1, tok2]
"""
tok1, tok2, tok3 = self.tokens
k1 = self.parser.KleeneStar_n("k1", 0, 2, tok1)
k2 = self.parser.KleeneStar_n("k2", 1, 2, tok2)
seq = self.parser.Sequence_n("seq", [k1, k2])
self.parser.build_first_sets()
assert seq.first_set == [tok1, tok2]
def test_token_comparison(self):
tok1 = self.parser.Token_n( "tok1", "foo" )
tok1b = self.parser.Token_n( "tok1", "foo" )
tok2 = self.parser.Token_n( "tok2", "foo" )
tok3 = self.parser.Token_n( "tok2", None )
assert tok1 == tok1b
assert tok1 != tok2
assert tok2 != tok3
class TestLookAheadBasics:
def setup_method(self, method):
self.parser = Parser()
self.tok1 = self.parser.Token_n("t1", 'foo')
self.tok2 = self.parser.Token_n("t2", 'bar')
self.tok3 = self.parser.Token_n("t3", 'foobar')
self.tokens = [self.tok1, self.tok2, self.tok3]
self.parser.build_first_sets()
def test_basic_token(self):
assert self.tok1.get_first_set() == {self.tok1: None}
def test_basic_alternative(self):
alt = self.parser.Alternative_n("a1t", self.tokens)
self.parser.build_first_sets()
assert alt.get_first_set() == dict.fromkeys(self.tokens)
def test_basic_sequence(self):
seq = self.parser.Sequence_n("seq", self.tokens)
self.parser.build_first_sets()
assert seq.get_first_set() == {self.tokens[0]: None}
def test_basic_kleenstar(self):
tok1, tok2, tok3 = self.tokens
kstar1 = self.parser.KleeneStar_n("k", 1, 3, tok1)
kstar2 = self.parser.KleeneStar_n("k2", 0, 3, tok1)
self.parser.build_first_sets()
assert kstar1.get_first_set() == {tok1: None}
assert kstar2.get_first_set() == {tok1: None,
self.parser.EmptyToken: None}
def test_maybe_empty_sequence(self):
"""S -> tok1{0,2} tok2{0,2}
==> S.first_set = {tok1, tok2, EmptyToken}
"""
tok1, tok2, tok3 = self.tokens
k1 = self.parser.KleeneStar_n( "k1", 0, 2, tok1)
k2 = self.parser.KleeneStar_n("k2", 0, 2, tok2)
seq = self.parser.Sequence_n( "seq", [k1, k2])
self.parser.build_first_sets()
assert seq.get_first_set() == {tok1: None,
tok2: None,
self.parser.EmptyToken: None}
def test_not_empty_sequence(self):
"""S -> tok1{0,2} tok2{1,2}
==> S.first_set = {tok1, tok2}
"""
tok1, tok2, tok3 = self.tokens
k1 = self.parser.KleeneStar_n("k1", 0, 2, tok1)
k2 = self.parser.KleeneStar_n("k2", 1, 2, tok2)
seq = self.parser.Sequence_n("seq", [k1, k2])
self.parser.build_first_sets()
assert seq.get_first_set() == {tok1: None, tok2: None}
def test_token_comparison(self):
tok1 = self.parser.Token_n( "tok1", "foo" )
tok1b = self.parser.Token_n( "tok1", "foo" )
tok2 = self.parser.Token_n( "tok2", "foo" )
tok3 = self.parser.Token_n( "tok2", None )
assert tok1.eq(tok1b)
assert not tok1.eq(tok2)
assert not tok2.eq(tok3)