def parse_keyword(string: str) -> Maybe[Tuple[str, str]]:
matchObj = re.match(
r"class |constructor |function |method |field |static |var |int|char|boolean|void|true|false|null|this|let |do |if|else|while|return",
string,
)
if matchObj:
return Some((matchObj.group(), "keyword"))
return Fail()
def parse_identifier(string: str) -> Maybe[Tuple[str, str]]:
matchObj = re.match(r"(_|[a-z]|[A-Z])\w*", string)
if matchObj:
return Some((matchObj.group(), "identifier"))
return Fail()
def parse_integer_constant(string: str) -> Maybe[Tuple[str, str]]:
matchObj = re.match(r"\d+", string)
if matchObj:
return Some((matchObj.group(), "integerConstant"))
return Fail()
def parse_string_constant(string: str) -> Maybe[Tuple[str, str]]:
matchObj = re.match(r"\"(.*?)\"", string)
if matchObj:
return Some((matchObj.group(), "stringConstant"))
return Fail()
def parse_symbol(string: str) -> Maybe[Tuple[str, str]]:
matchObj = re.match(r"[{}()[\].,;+\-*/&|<>=~]", string)
if matchObj:
return Some((matchObj.group(), "symbol"))
return Fail()