def test_parse_existed_implicit_combinator():
# comb := STRING
grammar = Grammar()
token_id = grammar.add_implicit('(')
result = make_combinator(grammar, '"("')
assert isinstance(result, TokenCombinator)
assert result.token_id == token_id
def test_parse_token_combinator():
# comb := NAME
grammar = Grammar()
token_id = grammar.add_token('Name')
result = make_combinator(grammar, 'Name')
assert isinstance(result, TokenCombinator)
assert result.token_id == token_id
def test_parse_repeat_combinator():
# comb := '{' seq '}'
grammar = Grammar()
token_id = grammar.add_token('Name')
result = make_combinator(grammar, '{ Name }')
assert isinstance(result, RepeatCombinator)
assert isinstance(result.combinator, TokenCombinator)
assert result.combinator.token_id == token_id
def test_parse_optional_combinator():
# comb := '[' seq ']'
grammar = Grammar()
token_id = grammar.add_token('Name')
result = make_combinator(grammar, '[ Name ]')
assert isinstance(result, OptionalCombinator)
assert isinstance(result.combinator, TokenCombinator)
assert result.combinator.token_id == token_id
def test_parse_parselet_with_priority_combinator():
# comb := NAME
grammar = Grammar()
parser_id = grammar.add_parselet('name')
result = make_combinator(grammar, 'name <100>')
assert isinstance(result, ParseletCombinator)
assert result.parser_id == parser_id
assert result.priority == 100
def main():
grammar = Grammar()
# core grammar
grammar.extend(create_core_grammar())
# combinator grammars
grammar.extend(create_combinator_grammar())
# add macro grammar. e.g. expr
grammar.add_parser('macro',
'name:Name "::=" combinator: combinator_sequence')
# # dump grammar
# dump_grammar(sys.stdout, grammar)
content = """
expr ::= 1 2 3 ; |
def main(): pass
""".strip()
#
scanner = DefaultScanner(grammar, '<example>', content)
parser = Parser(scanner)
try:
parser.parse(grammar.parselets['macro'])
except ParserError as ex:
ex.to_stream(create_writer(sys.stderr), content)
exit(1)
def test_parse_token_priority_fail_combinator():
# comb := NAME
grammar = Grammar()
grammar.add_token('Name')
with pytest.raises(DiagnosticError):
make_combinator(grammar, 'Name <100>')