Online Playground: unknown parser error type ->13<-

I’m trying to build my grammar from the ground up now, making strange and super simplified versions to make sure that is working and then extend from there. I started with the json example. Below I post a working example, with one line commented out. If you turn it one you get the following error: unknown parser error type ->13<-

If you comment the line above out and then uncomment the other I get the error Cannot read property chunkSize of undefined

Im not sure how to continue to build the grammer or why this won’t work.

(function jsonGrammarOnlyExample() {
  // ----------------- Lexer -----------------
  const createToken = chevrotain.createToken;
  const Lexer = chevrotain.Lexer;

    const This = createToken({name: "This", pattern: /this/});
    const New = createToken({name: "New", pattern: /new/});
    const LParen = createToken({name: "LParen", pattern: /\(/});
    const RParen = createToken({name: "RParen", pattern: /\)/});
    const LCurly = createToken({name: "LCurly", pattern: /{/});
    const RCurly = createToken({name: "RCurly", pattern: /}/});
    const LSquare = createToken({name: "LSquare", pattern: /\[/});
    const RSquare = createToken({name: "RSquare", pattern: /]/});
    const Comma = createToken({name: "Comma", pattern: /,/});
    const Period = createToken({name: "Period", pattern: /\./});
    const Colon = createToken({name: "Colon", pattern: /:/});
    const SemiColon = createToken({name: "SemiColon", pattern: /;/});
    const Equals = createToken({name: "Equals", pattern: /=/});
  
  const Literal = createToken({
        name: "Literal", pattern: /\"[^\"^\n]*\"/
    });
    const Number = createToken({
        name: "Number", pattern: /[0-9]+(?:\.[0-9]+)?[^\s]+\b/
    });
    const Label = createToken({
        name: "Label", pattern: /([a-zA-Z]{1})([a-zA-Z0-9\-_]+)?/
    });
    const WhiteSpace = createToken({
        name: "WhiteSpace",
        pattern: /\s+/,
        group: Lexer.SKIPPED
    });
  
  const StringLiteral = createToken({
    name: "StringLiteral", pattern: /"(:?[^\\"\n\r]+|\\(:?[bfnrtv"\\/]|u[0-9a-fA-F]{4}))*"/
  });
  const NumberLiteral = createToken({
    name: "NumberLiteral", pattern: /-?(0|[1-9]\d*)(\.\d+)?([eE][+-]?\d+)?/
  });

  const jsonTokens = [WhiteSpace,
        This,
        New,
        LParen,
        RParen,
        LCurly,
        RCurly,
        LSquare,
        RSquare,
        Comma,
        Period,
        Colon,
        SemiColon,
        Equals,
        Number,
        Literal,
        Label];

  const JsonLexer = new Lexer(jsonTokens, {
    // Less position info tracked, reduces verbosity of the playground output.
    positionTracking: "onlyStart"
  });

  // Labels only affect error messages and Diagrams.
  LCurly.LABEL = "'{'";
  RCurly.LABEL = "'}'";
  LSquare.LABEL = "'['";
  RSquare.LABEL = "']'";
  Comma.LABEL = "','";
  Colon.LABEL = "':'";
 LParen.LABEL = "'('";
    RParen.LABEL = "')'";
    Period.LABEL = "'.'";
    SemiColon.LABEL = "';'";
    Equals.LABEL = "'='";

  // ----------------- parser -----------------
  const Parser = chevrotain.Parser;

  class JsonParser extends Parser {
    constructor(input) {
      super(input, jsonTokens, {
        recoveryEnabled: true,
        // This will automatically create a Concrete Syntax Tree
        // You can inspect this structure in the output window.
        outputCst: true
      })

      const $ = this;

      $.RULE("Expression", () => {
        $.SUBRULE($.PropertyDefinition)
      });
      
		$.RULE("PropertyCall", () => {
                $.SUBRULE($.UriResource),
                $.CONSUME(Period),
                $.SUBRULE2($.UriResource)              
            });
      
       $.RULE("Evaluation", () => {
                $.OR([
                    {ALT: () => { $.CONSUME(Number) }},
                    //{ALT: () => { $.SUBRULE($.UriResource) }},
                    //turn this line on and you get unknown parser error type 13
                    //turn it on and turn the line above off and you get Cannot read property chunkSize of undefined
                    {ALT: () => { $.SUBRULE($.PropertyCall) }}
                ]);
            });
      
      $.RULE("PropertyDefinition", () => {
                $.SUBRULE($.PropertyCall),
                $.OR([
                    {ALT: () => { $.CONSUME(Colon) }},
                    {ALT: () => { $.CONSUME(Equals) }}
                ]),
                $.SUBRULE2($.Evaluation)
            });
      
      
     
     $.RULE("UriResource", () => {
                $.CONSUME(Label)
            });


      // very important to call this after all the rules have been setup.
      // otherwise the parser may not work correctly as it will lack information
      // derived from the self analysis.
      this.performSelfAnalysis();
    }

  }

  // for the playground to work the returned object must contain these fields
  return {
    lexer: JsonLexer,
    parser: JsonParser,
    defaultRule: "Expression"
  };
}())

[flyon]

Hi @bd82 , thanks for quick reply. Right, I was just trying to get something working online before installing via npm, but I see what you mean now, it would have saved me time to just try things right from my IDE and I would have had better / more clear errors. Thanks for the tips, I will continue trying things out in the IDE

[bd82]

I am leaving this open to investigate the playground not showing the correct error message.