Antlr4.Semantics.BasicSemanticChecks.CheckTokenOptions C# (CSharp) Method

        internal virtual bool CheckTokenOptions(TerminalAST elem, GrammarAST ID, GrammarAST valueAST)
        {
            IToken optionID = ID.Token;
            string fileName = optionID.InputStream.SourceName;
            // don't care about ID<ASTNodeName> options
            if (valueAST != null && !Grammar.tokenOptions.Contains(optionID.Text))
            {
                g.tool.errMgr.GrammarError(ErrorType.ILLEGAL_OPTION,
                                           fileName,
                                           optionID,
                                           optionID.Text);
                return false;
            }
            // TODO: extra checks depending on terminal kind?
            return true;
        }