def test_lifted():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_literal(Rule.entry, 'hello world')
grammar.set_flag(Rule.entry, P4.LIFTED)
assert grammar.parse("hello world") is None
def test_literal():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_literal(Rule.entry, 'hello world')
assert grammar.parse("hello world").slice == slice(0, 11)
with pytest.raises(P4.MatchError):
assert grammar.parse("hello,world")
def test_range():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_range(Rule.entry, 'a', 'z')
assert grammar.parse("x").slice == slice(0, 1)
with pytest.raises(P4.MatchError):
assert grammar.parse("1")
def test_repeat_max():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_repeat_max(Rule.entry, grammar.literal('o'), 3)
assert grammar.parse("") is None
assert grammar.parse("oo").slice == slice(0, 2)
assert grammar.parse("ooo").slice == slice(0, 3)
assert grammar.parse("oooo").slice == slice(0, 3)
def test_zero_or_once():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_zero_or_once(
Rule.entry,
grammar.literal('o'),
)
assert grammar.parse("") is None
assert grammar.parse("o").slice == slice(0, 1)
def test_spaced():
class Rule(IntEnum):
entry = 1
whitespace = 2
grammar = P4.Grammar()
grammar.add_literal(Rule.whitespace, ' ')
grammar.set_flag(Rule.whitespace, P4.SPACED)
grammar.add_sequence(Rule.entry, grammar.literal('o'),
grammar.literal('x'))
ast = grammar.parse("o x", entry=Rule.entry)
assert ast.slice == slice(0, 3)
def test_repeat_exact():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_repeat_exact(Rule.entry, grammar.literal('o'), 3)
assert grammar.parse("ooo").slice == slice(0, 3)
assert grammar.parse("oooo").slice == slice(0, 3)
with pytest.raises(P4.MatchError):
grammar.parse("oo")
def test_positive():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_positive(
Rule.entry,
grammar.literal('o'),
)
assert grammar.parse("o") is None
with pytest.raises(P4.MatchError):
assert grammar.parse("x")
def test_reference():
class Rule(IntEnum):
entry = 1
dest = 2
grammar = P4.Grammar()
grammar.add_literal(Rule.dest, 'world')
grammar.add_sequence(Rule.entry, grammar.literal('hello '),
grammar.reference(Rule.dest))
ast = grammar.parse("hello world", entry=Rule.entry)
assert ast.slice == slice(0, 11)
assert ast.children
assert ast.children[0].slice == slice(6, 11)
def test_squashed():
class Rule(IntEnum):
entry = 1
dest = 2
grammar = P4.Grammar()
grammar.add_literal(Rule.dest, 'world')
grammar.add_sequence(Rule.entry, grammar.literal('hello '),
grammar.reference(Rule.dest))
grammar.set_flag(Rule.entry, P4.SQUASHED)
ast = grammar.parse("hello world", entry=Rule.entry)
assert ast.slice == slice(0, 11)
assert ast.children == []
def test_once_or_more():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_once_or_more(
Rule.entry,
grammar.literal('o'),
)
assert grammar.parse("o").slice == slice(0, 1)
assert grammar.parse("oooo").slice == slice(0, 4)
with pytest.raises(P4.MatchError):
assert grammar.parse("") is None
def test_back_reference():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_sequence(
Rule.entry,
grammar.literal('o'),
grammar.literal('x'),
grammar.back_reference(0),
)
assert grammar.parse("oxo").slice == slice(0, 3)
with pytest.raises(P4.MatchError):
assert grammar.parse("oxx")
def test_choice():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_choice(
Rule.entry,
grammar.literal('a'),
grammar.literal('b'),
grammar.literal('c'),
)
assert grammar.parse("a").slice == slice(0, 1)
with pytest.raises(P4.MatchError):
grammar.parse("d")
def test_sequence():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_sequence(
Rule.entry,
grammar.literal('a'),
grammar.literal('b'),
grammar.literal('c'),
)
assert grammar.parse("abc").slice == slice(0, 3)
with pytest.raises(P4.MatchError):
assert grammar.parse("cba")
def test_repeat():
class Rule(IntEnum):
entry = 1
grammar = P4.Grammar()
grammar.add_repeat_min_max(Rule.entry, grammar.literal('o'), 2, 3)
assert grammar.parse("oo").slice == slice(0, 2)
assert grammar.parse("ooo").slice == slice(0, 3)
assert grammar.parse("oooo").slice == slice(0, 3)
with pytest.raises(P4.MatchError):
assert grammar.parse("") is None
with pytest.raises(P4.MatchError):
assert grammar.parse("o") == slice(0, 1)