java-如何强制ANTLR解析所有输入CharStream

我正在使用ANTLR4解析语法文件.当我使用BaseErrorListener来检测错误时,出现了问题.当面对非法输入字符串时,ANTLR自动匹配相应的分支,然后忽略后续的字符流,即使其中包含错误.我想检测该错误.这是我的g4文件和java文件.
  TransitionLexer是我的词法分析器文件,TransitionCondition是我的解析器文件. ErrorDialogListener.java是我的errorListener和Test.java id主Java文件.

TransitionLexer.g4

lexer grammar TransitionLexer;

BOOLEAN: 'true' | 'false';
IF: 'if';
THEN: 'then';
ELSE: 'else';

NAME: (ALPHA | CHINESE | '_')(ALPHA | CHINESE | '_'|DIGIT)*;

ALPHA: [a-zA-Z];
CHINESE: [\u4e00-\u9fa5];

NUMBER: INT | REAL;
INT: DIGIT+
    |'(-'DIGIT+')';
REAL: DIGIT+ ('.' DIGIT+)?
    | '(-' DIGIT+ ('.' DIGIT+)? ')';
fragment DIGIT: [0-9];

OPCOMPARE: '='|'>='|'<='|'>'|'<';
WS: [ \t\n\r]+ ->skip;
SL_COMMENT:  '/*' .*? '*/' ->skip;

TransitionCondition.g4

grammar TransitionCondition;
import TransitionLexer;

condition : stat+;
stat : expr;
expr: expr (('and' | 'or') expr)+
    | '(' expr ')'
    | '(' var OPCOMPARE value ')'
    | booleanExpr
    | BOOLEAN
    ;

var: localStates
     | globalStates
     | connector
     ;
localStates: NAME;
globalStates: 'Top' ('.' brick)+ '.' NAME;
connector: brick '.' NAME;

value: userdefinedValue | basicValue;
userdefinedValue: NAME;
basicValue: basicValue op=('*'|'/') basicValue
                    | basicValue op=('+' | '-') basicValue
                    | basicValue ('and' | 'or') basicValue
                    | NUMBER | BOOLEAN
                    | '(' basicValue ')'
                    ;

booleanExpr: booleanExpr OPCOMPARE booleanExpr
           | '(' booleanExpr ')'
           | NUMBER (OPCOMPARE|'*'| '/'|'+'|'-') NUMBER
           ;
brick: NAME;

ErrorDialogListener.java

package errorprocess;

import java.awt.Color;
import java.awt.Container;
import java.util.Collections;
import java.util.List;

import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;

import org.antlr.v4.runtime.BaseErrorListener;
import org.antlr.v4.runtime.Parser;
import org.antlr.v4.runtime.RecognitionException;
import org.antlr.v4.runtime.Recognizer;
import org.antlr.v4.runtime.atn.ATNConfigSet;
import org.antlr.v4.runtime.dfa.DFA;

public class ErrorDialogListener extends BaseErrorListener {


    @Override
    public void reportContextSensitivity(Parser recognizer, DFA dfa, int startIndex, int stopIndex, int prediction,
            ATNConfigSet configs) {
        System.out.println(dfa.toLexerString());
        System.out.println(dfa.getStates());        
        super.reportContextSensitivity(recognizer, dfa, startIndex, stopIndex, prediction, configs);
    }

    @Override
    public void syntaxError(Recognizer<?, ?> recognizer, Object offendingSymbol, int line, int charPositionInLine,
            String msg, RecognitionException e) {
        List<String> stack = ((Parser)recognizer).getRuleInvocationStack();
        Collections.reverse(stack);
        StringBuilder buf = new StringBuilder();
        buf.append("rule stack: "+stack+" ");
        buf.append("line "+line+":"+charPositionInLine+" at "+
                   offendingSymbol+": "+msg);

        JDialog dialog = new JDialog();
        Container contentPane = dialog.getContentPane();
        contentPane.add(new JLabel(buf.toString()));
        contentPane.setBackground(Color.white);
        dialog.setTitle("Syntax error");
        dialog.pack();
        dialog.setLocationRelativeTo(null);
        dialog.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        dialog.setVisible(true);
    }

}

Test.java

package errorprocess;

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;

import org.antlr.v4.runtime.*;
import org.antlr.v4.runtime.atn.PredictionMode;

import antlr4.my.transition.TransitionConditionLexer;
import antlr4.my.transition.TransitionConditionParser;

public class Test {

    public static void main(String[] args) throws IOException {
        InputStream in = new FileInputStream("G:\\AltaRica\\ANTLR4\\test\\condition\\t.expr");
        ANTLRInputStream input = new ANTLRInputStream(in);
        TransitionConditionLexer lexer = new TransitionConditionLexer(input);
        CommonTokenStream tokens = new CommonTokenStream(lexer);
        TransitionConditionParser parser = new TransitionConditionParser(tokens);
        parser.removeErrorListeners();
        parser.addErrorListener(new ErrorDialogListener());
//        parser.addErrorListener(new DiagnosticErrorListener());
//        parser.getInterpreter().setPredictionMode(PredictionMode.LL_EXACT_AMBIG_DETECTION);
//        parser.getInterpreter().setPredictionMode(PredictionMode.LL);
        parser.condition();
    }

}

主要问题

当我的输入是
(top.b2.states =标称值)和(b1.i1 =错误)和(states> = 5.5),解析器可以正常工作.
但是当我的输入是(Top.b2.states =名义)aaa(b1.i1 =错误)和(states> = 5.5)时,解析器仅解析(Top.b2.states =名义)并且忽略aaa之后的单词,与语法文件不正确.
我猜想原因是解析器遵循了我在TransitionCondition.g4中的第一条规则的第二个分支,即expr：'(‘expr’)’,而忽略了其他规则.那么,在这种情况下,如何强制ANTLR识别所有输入,或者如何强制ANTLR仅选择第一个分支(expr：expr((‘and’|’or’)expr))？

我尝试过的

我尝试使用DiagnosticErrorListener或重写reportContextSensitivity(),但似乎无法正常工作.

解决方法:

您的主要规则必须以EOF令牌结尾-EOF令牌是ANTLR提供的与输入结尾匹配的特殊令牌.

如果令牌不存在,则ANTLR只会解析它可以匹配的任何内容,然后停止.通过将EOF放在输入规则的末尾,可以告诉ANTLR它解析的内容必须在输入的末尾结束.

标签：antlr4,java,parsing,antlr
来源： https://codeday.me/bug/20191012/1898863.html