如何在python中运行antlr代码并验证我的输入

Question

我有一个简单的语法文件hello.g contains

grammar Hello_world;
utterance : greeting | exclamation;
greeting : interjection subject;
exclamation : 'Hooray!';
interjection : 'Hello';
subject : 'World!';

验证字符串'Hello World！'和'万岁！'

但是如何测试这个语法？在某处我读到我们需要编译解析器和其他人。我是ANTLR的新手，请帮忙。

我使用AntlrWorks1.5生成词法分析器和解析器; 之后使用以下代码运行测试：

import antlr3
from helloworldLexer import helloworldLexer
from helloworldParser import helloworldParser

while True:
    expr = raw_input('>>> ')
    if expr == '':
        break

    cStream = antlr3.StringStream(expr)
    lexer = helloworldLexer(cStream)
    tStream = antlr3.CommonTokenStream(lexer)
    parser = helloworldParser(tStream)
    result = parser.evaluate()
    print result

当我运行上面的python文件时，得到以下错误：

>>> Hello World!
Traceback (most recent call last):
  File "C:\Users\Lenovo\workspace\antlr\output\hello.py", line 12, in <module>
    lexer = helloworldLexer(cStream)
  File "C:\Users\Lenovo\workspace\antlr\output\helloworldLexer.py", line 26, in __init__
    state = RecognizerSharedState()
NameError: global name 'RecognizerSharedState' is not defined