def test_missing_rule():
grammar = '''
@@grammar::TestGrammar
block = test ;
'''
try:
parse(grammar, 'abc')
except GrammarError as e:
assert str(e) == 'Unknown rules, no parser generated:\ntest'
def test_leftrec_with_void(self):
left_grammar = '''
@@left_recursion :: True
@@nameguard :: False
start = A | () ;
A = | A 'a' | 'a' ;
'''
assert (('a', 'a'), 'a') == parse(left_grammar, 'aaa')
assert parse(left_grammar, '') is None
def test_alert_interpolation():
input = '42 69'
grammar = '''
start = a:number b: number i:^`"seen: {a}, {b}"` $ ;
number = /\d+/ ;
'''
assert parse(grammar, input) == {'a': '42', 'b': '69', 'i': 'seen: 42, 69'}
def test_constant_interpolation_free():
input = '42 69'
grammar = '''
start = a:number b: number i:`seen: {a}, {b}` $ ;
number = /\d+/ ;
'''
assert parse(grammar, input) == {'a': '42', 'b': '69', 'i': 'seen: 42, 69'}
def test_nullable_void(self):
left_grammar = '''
@@left_recursion :: True
@@nameguard :: False
start = A $ ;
A = | A 'a' | () ;
'''
assert (('a', 'a'), 'a') == parse(left_grammar, 'aaa')
def test_peg_associativity(self):
left_grammar = '''
@@left_recursion :: True
@@nameguard :: False
start = A $ ;
A = | A 'a' | 'a' A | 'a' ;
'''
assert [['a', 'a'], 'a'] == parse(left_grammar, 'aaa')
right_grammar = '''
@@left_recursion :: True
@@nameguard :: False
start = A $ ;
A = | 'a' A | A 'a' | 'a' ;
'''
assert ['a', ['a', 'a']] == parse(right_grammar, 'aaa')
def test_associativity(self):
left_grammar = '''
@@left_recursion :: True
@@nameguard :: False
start = A $ ;
A = | A 'a' | 'a' ;
'''
assert (('a', 'a'), 'a') == parse(left_grammar, 'aaa')
right_grammar = '''
@@left_recursion :: True
@@nameguard :: False
start = A $ ;
A = | 'a' A | 'a' ;
'''
assert ('a', ('a', 'a')) == parse(right_grammar, 'aaa')
def test_not_at_top_level(self):
grammar = r"""
identifier = /\w+/ ;
type = (vector_type | leaf_type) ;
vector_type = base:type '[]' ;
leaf_type = id:identifier ;
decl = type:type name:identifier ;
"""
self.assertEquals(
{'type': {'id': 'int'}, 'name': 'x'},
parse(grammar, 'int x', start='decl').asjson()
)
def test_constant_interpolation_multiline():
input = '42 69'
grammar = '''
start = a:number b: number
i:```
seen:
{a}
{b}
``` $ ;
number = /\d+/ ;
'''
result = parse(grammar, input)
print(result)
assert result == {'a': '42', 'b': '69', 'i': 'seen:\n42\n69\n'}
