from pyparsing import *

class Lexer:
    def __init__(self, program):
        star = Regex("\*").setResultsName('star')
        oper_left = Regex("\(").setResultsName('oper_left')
        oper_right = Regex("\)").setResultsName('oper_right')
        text = Regex("\"[a-z*(+)]+\"").setResultsName('text')
        identify = Regex("[A-Z]p|[A-Z]").setResultsName('ident')

        lexems = OneOrMore(Group(identify) | Group(oper_left) | Group(oper_right) | Group(text) | Group(star))
        lexems = lexems.parseString(program)

        self.lexems = list(reversed([lexem.items()[0] for lexem in lexems]))

    def next_token(self):
        return self.lexems.pop() if self.lexems else False

    def cur_token(self):
        return self.lexems[-1] if self.lexems else False

    def cur_token_is_star(self):
        return self.lexems[-1][0] == 'star' if self.lexems else False

    def cur_token_is_ident(self):
        return self.lexems[-1][0] == 'ident' if self.lexems else False

    def cur_token_is_text(self):
        return self.lexems[-1][0] == 'text' if self.lexems else False

    def cur_token_is_oper_left(self):
        return self.lexems[-1][0] == 'oper_left' if self.lexems else False

    def cur_token_is_oper_right(self):
        return self.lexems[-1][0] == 'oper_right' if self.lexems else False