/// <summary>
/// Returns all values from array according filter expression or all values (index = MaxValue)
/// </summary>
public static IEnumerable <BsonValue> ARRAY_FILTER(BsonValue value, int index, BsonExpression filterExpr, BsonDocument root, BsonDocument parameters)
{
if (!value.IsArray)
{
yield break;
}
var arr = value.AsArray;
// [*] - index are all values
if (index == int.MaxValue)
{
foreach (var item in arr)
{
yield return(item);
}
}
// [<expr>] - index are an expression
else
{
// update parameters in expression
parameters.CopyTo(filterExpr.Parameters);
foreach (var item in arr)
{
// execute for each child value and except a first bool value (returns if true)
var c = filterExpr.ExecuteScalar(new BsonDocument[] { root }, root, item);
if (c.IsBoolean && c.AsBoolean == true)
{
yield return(item);
}
}
}
}
/// <summary>
/// Returns a single value from array according index or expression parameter
/// </summary>
public static BsonValue ARRAY_INDEX(BsonValue value, int index, BsonExpression expr, BsonDocument root, BsonDocument parameters)
{
if (!value.IsArray)
{
return(BsonValue.Null);
}
var arr = value.AsArray;
// for expr.Type = parameter, just get value as index (fixed position)
if (expr.Type == BsonExpressionType.Parameter)
{
// update parameters in expression
parameters.CopyTo(expr.Parameters);
// get fixed position based on parameter value (must return int value)
var indexValue = expr.ExecuteScalar(root);
if (!indexValue.IsNumber)
{
throw new LiteException(0, "Parameter expression must return number when called inside an array");
}
index = indexValue.AsInt32;
}
var idx = index < 0 ? arr.Count + index : index;
if (arr.Count > idx)
{
return(arr[idx]);
}
return(BsonValue.Null);
}
public static IEnumerable <BsonValue> FILTER(BsonDocument root, Collation collation, BsonDocument parameters, IEnumerable <BsonValue> input, BsonExpression filterExpr)
{
foreach (var item in input)
{
// execute for each child value and except a first bool value (returns if true)
var c = filterExpr.ExecuteScalar(new BsonDocument[] { root }, root, item, collation);
if (c.IsBoolean && c.AsBoolean == true)
{
yield return(item);
}
}
}
public static IEnumerable <BsonValue> FILTER(IEnumerable <BsonValue> input, BsonExpression filterExpr, BsonDocument root, BsonDocument parameters)
{
// update parameters in expression
parameters.CopyTo(filterExpr.Parameters);
foreach (var item in input)
{
// execute for each child value and except a first bool value (returns if true)
var c = filterExpr.ExecuteScalar(new BsonDocument[] { root }, root, item);
if (c.IsBoolean && c.AsBoolean == true)
{
yield return(item);
}
}
}
public static IEnumerable <BsonValue> SORT(BsonDocument root, Collation collation, BsonDocument parameters, IEnumerable <BsonValue> input, BsonExpression sortExpr, BsonValue order)
{
IEnumerable <Tuple <BsonValue, BsonValue> > source()
{
foreach (var item in input)
{
var value = sortExpr.ExecuteScalar(new BsonDocument[] { root }, root, item, collation);
yield return(new Tuple <BsonValue, BsonValue>(item, value));
}
}
return((order.IsInt32 && order.AsInt32 > 0) || (order.IsString && order.AsString.Equals("asc", StringComparison.OrdinalIgnoreCase)) ?
source().OrderBy(x => x.Item2, collation).Select(x => x.Item1) :
source().OrderByDescending(x => x.Item2, collation).Select(x => x.Item1));
}
