ANTLR3处理错误的问题

问题描述

我尝试按照以下方式报告错误.

I tried error reporting in following manner.

@members{
    public String getErrorMessage(RecognitionException e,String[] tokenNames)
    {
        List stack=getRuleInvocationStack(e,this.getClass().getName());
        String msg=null;
        if(e instanceof NoViableAltException){
            <some code>
        }
        else{
            msg=super.getErrorMessage(e,tokenNames);
        }
        String[] inputLines = e.input.toString().split("\r\n");
        String line = "";
        if(e.token.getCharPositionInLine()==0)
            line =  "at \"" + inputLines[e.token.getLine() - 2];
        else if(e.token.getCharPositionInLine()>0)
            line =  "at \"" + inputLines[e.token.getLine() - 1];
        return ": " + msg.split("at")[0] + line + "\" => [" + stack.get(stack.size() - 1) + "]";
    }

    public String getTokenErrorDisplay(Token t){
        return t.toString();
    }
}

现在错误显示如下.

line 6:7 : missing CLOSSB at "int a[6;" => [var_declaration]
line 8:0 : missing SEMICOL at "int p" => [var_declaration]
line 8:5 : missing CLOSB at "get(2;" => [call]

我有2个问题.

1)有正确的方法来做我做过的同样的事情吗?

1) Is there a proper way to do the same thing I have done?

2)我想用其真实符号替换CLOSSB，SEMICOL，CLOSB等.如何使用.g文件中的地图来做到这一点?

2) I want to replace CLOSSB, SEMICOL, CLOSB etc. with their real symbols. How can I do that using the map in .g file?

谢谢.

推荐答案

* 1)是否有正确的方法来完成我做过的同样的事情?

*1) Is there a proper way to do the same thing I have done?

没有单一的方法可以做到这一点.请注意，正确的错误处理和报告非常棘手.特伦斯·帕尔(Terence Parr)在权威性ANTLR参考(该章10).我建议您拿一份副本并阅读.

There is no single way to do this. Note that proper error-handling and reporting is tricky. Terence Parr spends a whole chapter on this in The Definitive ANTLR Reference (chapter 10). I recommend you get hold of a copy and read it.

2)我想用其真实符号替换CLOSSB，SEMICOL，CLOSB等.如何使用.g文件中的地图来做到这一点?

不能.对于SEMICOL，这似乎很容易做到，但是您如何获取诸如FOO这样的令牌的信息:

You can't. For SEMICOL this may seem easy to do, but how would you get this information for a token like FOO:

FOO : (X | Y)+;

fragment X : '4'..'6';
fragment Y : 'a' | 'bc' | . ;

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