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 parse_expr(grammar: Grammar, content: str):
scanner = DefaultScanner(grammar, '<example>', content)
parser = Parser(scanner)
result = parser.parse(grammar.parselets['expr'])
return result
def parse_combinator(content: str):
scanner = DefaultScanner(combinator_grammar, '<example>', content)
parser = Parser(scanner)
return parser.parse(combinator_grammar.parselets['combinator_sequence'])