private void VisitBooleanComparisonExpression(BinaryExpression binaryExpression)
{
//Check if it is a string compareTo
if (FilterUtils.CheckIfStringCompareTo(binaryExpression, _inNot, out var stringComparison))
{
_stack.Push(stringComparison);
return;
}
var left = VisitPop <Expressions.ScalarExpression>(binaryExpression.Left);
var right = VisitPop <Expressions.ScalarExpression>(binaryExpression.Right);
Expressions.BooleanComparisonType booleanComparisonType = FilterUtils.ConvertNot(FilterUtils.ParseBooleanComparisonType(binaryExpression.NodeType), _inNot);
_stack.Push(new Expressions.BooleanComparisonExpression()
{
Type = booleanComparisonType,
Left = left,
Right = right
});
}
public static bool CheckIfStringCompareTo(BinaryExpression binaryExpression, bool isNot, out Expressions.BooleanComparisonExpression stringComparison)
{
stringComparison = null;
//check that it follows: o.prop.CompareTo("text") > < >= <= != == 0 1 -1
if (binaryExpression.Left.NodeType == ExpressionType.Call &&
binaryExpression.Left is MethodCallExpression methodCallExpression &&
methodCallExpression.Method.Name == "CompareTo" &&
methodCallExpression.Object is MemberExpression memberExpression &&
methodCallExpression.Object.Type.Equals(typeof(string)) &&
binaryExpression.Right.NodeType == ExpressionType.Constant &&
binaryExpression.Right is ConstantExpression constantExpression &&
methodCallExpression.Arguments.Count == 1 &&
methodCallExpression.Arguments[0] is ConstantExpression argumentExpression)
{
Expressions.BooleanComparisonType booleanComparisonType = FilterUtils.ParseBooleanComparisonType(binaryExpression.NodeType);
var compareValue = (long)Convert.ChangeType(constantExpression.Value, typeof(long));
var convertedComparison = ConvertNot(ConvertBooleanComparisonType(booleanComparisonType, compareValue), isNot);
var columnReference = new Expressions.ColumnReference()
{
Identifiers = new List <string>()
{
memberExpression.Member.Name
}
};
stringComparison = new Expressions.BooleanComparisonExpression()
{
Left = columnReference,
Right = new StringLiteral()
{
Value = (string)argumentExpression.Value
},
Type = convertedComparison
};
return(true);
}
return(false);
}
