ANTLR4終結Lexer/Parser錯誤Python

Question

我想知道如何在發現不匹配時保持詞法分析器或解析器不運行。例如，如果詞法分析器預期'。'我希望它不要繼續恢復模式。

Answer 1

這就是措辭對我來說：

import sys 
from antlr4 import * 
from bin.LEDSGrammarLexer import LEDSGrammarLexer 
from bin.LEDSGrammarParser import LEDSGrammarParser 
from bin.LEDSGrammarListener import LEDSGrammarListener 
from src.Gramatica import Gramatica 
from src.Traductor import Translator 
#Add This Library 
from antlr4.error.ErrorListener import ErrorListener 

import src.CuboSemantico 

class MyErrorListener(ErrorListener): 
    def syntaxError(self, recognizer, offendingSymbol, line, column, msg, e): 
     print str(line) + ":" + str(column) + ": sintax ERROR, " + str(msg) 
     print "Terminating Translation" 
     sys.exit() 

    def reportAmbiguity(self, recognizer, dfa, startIndex, stopIndex, exact, ambigAlts, configs): 
     print "Ambiguity ERROR, " + str(configs) 
     sys.exit() 

    def reportAttemptingFullContext(self, recognizer, dfa, startIndex, stopIndex, conflictingAlts, configs): 
     print "Attempting full context ERROR, " + str(configs) 
     sys.exit() 

    def reportContextSensitivity(self, recognizer, dfa, startIndex, stopIndex, prediction, configs): 
     print "Context ERROR, " + str(configs) 
     sys.exit() 

def main(argv): 
    print "Parsing: " + argv[1] + "\n" 
    input = FileStream(argv[1]) 
    lexer = LEDSGrammarLexer(input) 

    #This was the key! 
    stream = CommonTokenStream(lexer) 
    parser = LEDSGrammarParser(stream) 
    parser._listeners = [ MyErrorListener() ] 

    tree = parser.programa() 
    printer = Gramatica() 
    walker = ParseTreeWalker() 
    result = walker.walk(printer,tree) 
    print "Resultado del parseo" + str(result) 
    for idx,x in enumerate(printer.Cuadruplos): 
     print str(idx) +" - "+str(x) 
    translator = Translator() 
    translator.translate(printer) 
    #print(tree.toStringTree(recog=parser)) 

if __name__ == '__main__': 
    main(sys.argv) 

感謝： 「爲什麼？是不是這個代碼工作」 HAR

Reference Answer