private QueryExpression ParseExpression()
{
QueryExpression rootExpression = null;
CompositeExpression parentExpression = null;
while (_currentIndex < _expression.Length)
{
EatWhitespace();
if (_expression[_currentIndex] != '@')
throw new JsonException("Unexpected character while parsing path query: " + _expression[_currentIndex]);
_currentIndex++;
List<PathFilter> expressionPath = new List<PathFilter>();
if (ParsePath(expressionPath, _currentIndex, true))
throw new JsonException("Path ended with open query.");
EatWhitespace();
EnsureLength("Path ended with open query.");
QueryOperator op;
object value = null;
if (_expression[_currentIndex] == ')'
|| _expression[_currentIndex] == '|'
|| _expression[_currentIndex] == '&')
{
op = QueryOperator.Exists;
}
else
{
op = ParseOperator();
EatWhitespace();
EnsureLength("Path ended with open query.");
value = ParseValue();
EatWhitespace();
EnsureLength("Path ended with open query.");
}
BooleanQueryExpression booleanExpression = new BooleanQueryExpression
{
Path = expressionPath,
Operator = op,
Value = (op != QueryOperator.Exists) ? new JValue(value) : null
};
if (_expression[_currentIndex] == ')')
{
if (parentExpression != null)
{
parentExpression.Expressions.Add(booleanExpression);
return rootExpression;
}
return booleanExpression;
}
if (_expression[_currentIndex] == '&' && Match("&&"))
{
if (parentExpression == null || parentExpression.Operator != QueryOperator.And)
{
CompositeExpression andExpression = new CompositeExpression { Operator = QueryOperator.And };
if (parentExpression != null)
parentExpression.Expressions.Add(andExpression);
parentExpression = andExpression;
if (rootExpression == null)
rootExpression = parentExpression;
}
parentExpression.Expressions.Add(booleanExpression);
}
if (_expression[_currentIndex] == '|' && Match("||"))
{
if (parentExpression == null || parentExpression.Operator != QueryOperator.Or)
{
CompositeExpression orExpression = new CompositeExpression { Operator = QueryOperator.Or };
if (parentExpression != null)
parentExpression.Expressions.Add(orExpression);
parentExpression = orExpression;
if (rootExpression == null)
rootExpression = parentExpression;
}
parentExpression.Expressions.Add(booleanExpression);
}
}
throw new JsonException("Path ended with open query.");
}
public void BooleanExpressionTest()
{
BooleanQueryExpression e1 = new BooleanQueryExpression
{
Operator = QueryOperator.LessThan,
Value = new JValue(3),
Path = new List<PathFilter>
{
new ArrayIndexFilter()
}
};
Assert.True(e1.IsMatch(new JArray(1, 2, 3, 4, 5)));
Assert.True(e1.IsMatch(new JArray(2, 3, 4, 5)));
Assert.False(e1.IsMatch(new JArray(3, 4, 5)));
Assert.False(e1.IsMatch(new JArray(4, 5)));
BooleanQueryExpression e2 = new BooleanQueryExpression
{
Operator = QueryOperator.LessThanOrEquals,
Value = new JValue(3),
Path = new List<PathFilter>
{
new ArrayIndexFilter()
}
};
Assert.True(e2.IsMatch(new JArray(1, 2, 3, 4, 5)));
Assert.True(e2.IsMatch(new JArray(2, 3, 4, 5)));
Assert.True(e2.IsMatch(new JArray(3, 4, 5)));
Assert.False(e2.IsMatch(new JArray(4, 5)));
}