类 ParseTreeBuilder

  • 所有已实现的接口:
    DebugEventListener

    public class ParseTreeBuilder
    extends BlankDebugEventListener
    This parser listener tracks rule entry/exit and token matches to build a simple parse tree using ParseTree nodes.
    • 字段详细资料

      • EPSILON_PAYLOAD

        public static final java.lang.String EPSILON_PAYLOAD
        另请参阅:
        常量字段值
    • 构造器详细资料

      • ParseTreeBuilder

        public ParseTreeBuilder​(java.lang.String grammarName)
    • 方法详细资料

      • create

        public ParseTree create​(java.lang.Object payload)
        What kind of node to create. You might want to override so I factored out creation here.
      • epsilonNode

        public ParseTree epsilonNode()
      • enterRule

        public void enterRule​(java.lang.String filename,
                              java.lang.String ruleName)
        从接口复制的说明: DebugEventListener
        The parser has just entered a rule. No decision has been made about which alt is predicted. This is fired AFTER init actions have been executed. Attributes are defined and available etc... The grammarFileName allows composite grammars to jump around among multiple grammar files.
        指定者:
        enterRule 在接口中 DebugEventListener
        覆盖:
        enterRule 在类中 BlankDebugEventListener
      • exitRule

        public void exitRule​(java.lang.String filename,
                             java.lang.String ruleName)
        从接口复制的说明: DebugEventListener
        This is the last thing executed before leaving a rule. It is executed even if an exception is thrown. This is triggered after error reporting and recovery have occurred (unless the exception is not caught in this rule). This implies an "exitAlt" event. The grammarFileName allows composite grammars to jump around among multiple grammar files.
        指定者:
        exitRule 在接口中 DebugEventListener
        覆盖:
        exitRule 在类中 BlankDebugEventListener
      • recognitionException

        public void recognitionException​(RecognitionException e)
        从接口复制的说明: DebugEventListener
        A recognition exception occurred such as NoViableAltException. I made this a generic event so that I can alter the exception hierachy later without having to alter all the debug objects. Upon error, the stack of enter rule/subrule must be properly unwound. If no viable alt occurs it is within an enter/exit decision, which also must be rewound. Even the rewind for each mark must be unwount. In the Java target this is pretty easy using try/finally, if a bit ugly in the generated code. The rewind is generated in DFA.predict() actually so no code needs to be generated for that. For languages w/o this "finally" feature (C++?), the target implementor will have to build an event stack or something. Across a socket for remote debugging, only the RecognitionException data fields are transmitted. The token object or whatever that caused the problem was the last object referenced by LT. The immediately preceding LT event should hold the unexpected Token or char. Here is a sample event trace for grammar: b : C ({;}A|B) // {;} is there to prevent A|B becoming a set | D ; The sequence for this rule (with no viable alt in the subrule) for input 'c c' (there are 3 tokens) is: commence LT(1) enterRule b location 7 1 enter decision 3 LT(1) exit decision 3 enterAlt1 location 7 5 LT(1) consumeToken [c/<4>,1:0] location 7 7 enterSubRule 2 enter decision 2 LT(1) LT(1) recognitionException NoViableAltException 2 1 2 exit decision 2 exitSubRule 2 beginResync LT(1) consumeToken [c/<4>,1:1] LT(1) endResync LT(-1) exitRule b terminate
        指定者:
        recognitionException 在接口中 DebugEventListener
        覆盖:
        recognitionException 在类中 BlankDebugEventListener