我的简单ANTLR语法在解析时忽略某些无效标记

Question

几周前，我问了一个关于我的ANTLR语法的问题（我的简单ANTLR语法不像预期的那样工作）。自从问了这个问题后，我做了更多的挖掘和调试，并找出了大部分的问题。不过，我只剩下一个问题。

我生成的解析器代码不会在处理的文本的某个特定部分中提取无效标记。lexer可以正确地将内容分解为令牌，但在某些情况下，解析器不会删除无效的令牌。特别是，当无效令牌位于短语“a和”b“的末尾时，解析器会忽略它--就像令牌根本不在那里一样。

null

grammar QvidianPlaybooks; 
options{ language=CSharp3; output=AST; ASTLabelType = CommonTree; } 

public parse
  :  expression
  ;

LPAREN : '(' ;
RPAREN : ')' ;
ANDOR : 'AND'|'and'|'OR'|'or';
NAME : ('A'..'Z');
WS : ' ' { $channel = Hidden; };
THEREST : .;

// ***************** parser rules:
expression : anexpression EOF!;
anexpression : atom (ANDOR^ atom)*;
atom : NAME | LPAREN! anexpression RPAREN!;

... from the main program
QvidianPlaybooksLexer lexer = new QvidianPlaybooksLexer(new ANTLRStringStream(src));
QvidianPlaybooksParser parser = new QvidianPlaybooksParser(new CommonTokenStream(lexer));
parser.TreeAdaptor = new CommonTreeAdaptor();

CommonTree tree = (CommonTree)parser.parse().Tree;
ValidateTree(tree, 0, iValidIdentifierCount);

// recursive code that walks the tree
public static RuleLogicValidationResult ValidateTree(ITree Tree, int depth, int conditionCount)
{
    RuleLogicValidationResult rlvr = null;

    if (Tree != null)
    {
        CommonErrorNode commonErrorNode = Tree as CommonErrorNode;
        if (null != commonErrorNode)
        {
            rlvr = new RuleLogicValidationResult();
            rlvr.IsValid = false;
            rlvr.ErrorType = LogicValidationErrorType.Other;
            Console.WriteLine(rlvr.ToString());
        }
        else
        {
            string strTree = Tree.ToString();
            strTree = strTree.Trim();
            strTree = strTree.ToUpper();
            if ((Tree.ChildCount != 0) && (Tree.ChildCount != 2))
            {
                rlvr = new RuleLogicValidationResult();
                rlvr.IsValid = false;
                rlvr.ErrorType = LogicValidationErrorType.Other;
                rlvr.InvalidIdentifier = strTree;
                rlvr.ErrorPosition = 0;
                Console.WriteLine(String.Format("CHILD COUNT of {0} = {1}", strTree, tree.ChildCount));
            }
            // if the current node is valid, then validate the two child nodes
            if (null == rlvr || rlvr.IsValid)
            {
                // output the tree node
                for (int i = 0; i < depth; i++)
                {
                    Console.Write("  ");
                }
                Console.WriteLine(Tree);
                rlvr = ValidateTree(Tree.GetChild(0), depth + 1, conditionCount);
                if (rlvr.IsValid)
                {
                    rlvr = ValidateTree(Tree.GetChild(1), depth + 1, conditionCount);
                }
            }
            else
            {
                Console.WriteLine(rlvr.ToString());
            }
        }
    }
    else
    {
        // this tree is null, return a "it's valid" result
        rlvr = new RuleLogicValidationResult();
        rlvr.ErrorType = LogicValidationErrorType.None;
        rlvr.IsValid = true;
    }

    return rlvr;
}

Answer 1

将EOF添加到开始规则的末尾。：）