public override Node VisitVariable([NotNull] FormulaGrammerParser.VariableContext context) { var variableNameToken = context.IDENTIFIER().Symbol; if (this.configuration.HasConstant(variableNameToken.Text)) { return(new ConstantNode(variableNameToken.Text)); } if (this.configuration.IsVariablesSupportDisabled) { ParsingException.ThrowInvalidTokenException(variableNameToken); } var variableName = variableNameToken.Text; if (!this.configuration.IsVariableNameValidationDisabled && !this.configuration.HasVariable(variableName)) { ParsingException.ThrowUnknownVariableException(variableNameToken); } return(new VariableNode(variableName)); }