/// <summary>Converts the parameters to a constant day expression </summary>
/// <param name="expr">The function call expressions</param>
public object ToRelativeDate(BindingCallExpr expr)
{
var relativeDay = (string)(expr.ParamList[0]);
var dayOfWeek = Convert.ToInt32(expr.ParamList[1]);
var month = Convert.ToInt32(expr.ParamList[2]);
var token = expr.ParamList[3] as TokenData;
return(Exprs.DateRelative(relativeDay, dayOfWeek, month, token));
}