public static AstFilter Translate(TranslationContext context, BinaryExpression expression, Expression enumerableExpression, Expression sizeExpression)
{
var field = ExpressionToFilterFieldTranslator.Translate(context, enumerableExpression);
if (TryConvertSizeExpressionToBsonValue(sizeExpression, out var size))
{
var compareCountFilter = AstFilter.Size(field, size);
switch (expression.NodeType)
{
case ExpressionType.Equal: return(compareCountFilter);
case ExpressionType.NotEqual: return(AstFilter.Not(compareCountFilter));
}
}
throw new ExpressionNotSupportedException(expression);
}
public static AstFilter Translate(TranslationContext context, BinaryExpression expression, UnaryExpression arrayLengthExpression, Expression sizeExpression)
{
if (arrayLengthExpression.NodeType == ExpressionType.ArrayLength)
{
var arrayExpression = arrayLengthExpression.Operand;
var arrayField = ExpressionToFilterFieldTranslator.Translate(context, arrayExpression);
var size = sizeExpression.GetConstantValue <int>(containingExpression: expression);
switch (expression.NodeType)
{
case ExpressionType.Equal:
return(AstFilter.Size(arrayField, size));
case ExpressionType.NotEqual:
return(AstFilter.Not(AstFilter.Size(arrayField, size)));
}
}
throw new ExpressionNotSupportedException(expression);
}
public static AstFilter Translate(TranslationContext context, MethodCallExpression expression)
{
if (AllWithContainsInPredicateMethodToFilterTranslator.CanTranslate(expression, out var arrayFieldExpression, out var arrayConstantExpression))
{
return(AllWithContainsInPredicateMethodToFilterTranslator.Translate(context, arrayFieldExpression, arrayConstantExpression));
}
if (AnyWithContainsInPredicateMethodToFilterTranslator.CanTranslate(expression, out arrayFieldExpression, out arrayConstantExpression))
{
return(AnyWithContainsInPredicateMethodToFilterTranslator.Translate(context, arrayFieldExpression, arrayConstantExpression));
}
var method = expression.Method;
var arguments = expression.Arguments;
if (method.IsOneOf(EnumerableMethod.All, EnumerableMethod.Any, EnumerableMethod.AnyWithPredicate))
{
var sourceExpression = arguments[0];
var(field, filter) = FilteredEnumerableFilterFieldTranslator.Translate(context, sourceExpression);
if (method.IsOneOf(EnumerableMethod.All, EnumerableMethod.AnyWithPredicate))
{
var predicateLambda = (LambdaExpression)arguments[1];
var parameterExpression = predicateLambda.Parameters.Single();
var elementSerializer = ArraySerializerHelper.GetItemSerializer(field.Serializer);
var parameterSymbol = context.CreateSymbol(parameterExpression, "@<elem>", elementSerializer); // @<elem> represents the implied element
var predicateContext = context.WithSingleSymbol(parameterSymbol); // @<elem> is the only symbol visible inside an $elemMatch
var predicateFilter = ExpressionToFilterTranslator.Translate(predicateContext, predicateLambda.Body, exprOk: false);
filter = AstFilter.Combine(filter, predicateFilter);
}
if (method.Is(EnumerableMethod.All))
{
return(AstFilter.Not(AstFilter.ElemMatch(field, AstFilter.Not(filter))));
}
else
{
if (filter == null)
{
return(AstFilter.And(AstFilter.Ne(field, BsonNull.Value), AstFilter.Not(AstFilter.Size(field, 0))));
}
else
{
return(AstFilter.ElemMatch(field, filter));
}
}
}
throw new ExpressionNotSupportedException(expression);
}