public BlackboardConstraint()
{
m_firstValue = new MemoryVar();
m_secondValue = new MemoryVar();
m_valueType = ConditionValueType.Boolean;
m_booleanComparison = BooleanComparison.IsTrue;
m_numericComparison = NumericComparison.Equal;
m_referenceComparison = ReferenceComparison.IsNotNull;
}
public Expression <Func <TSourceType, bool> > NumericValueComparison <TSourceType>(string propertyName, NumericComparison comparison, double value)
{
var expTargetValue = Expression.Constant(value);
var expParameter = Expression.Parameter(typeof(TSourceType), "x");
Expression expGetProperty = Expression.PropertyOrField(expParameter, propertyName);
Expression body = null;
switch (comparison)
{
case NumericComparison.Eq:
body = Expression.Equal(expGetProperty, expTargetValue);
break;
case NumericComparison.Gt:
body = Expression.GreaterThan(expGetProperty, expTargetValue);
break;
case NumericComparison.Gte:
body = Expression.GreaterThanOrEqual(expGetProperty, expTargetValue);
break;
case NumericComparison.Lt:
body = Expression.LessThan(expGetProperty, expTargetValue);
break;
case NumericComparison.Lte:
body = Expression.LessThanOrEqual(expGetProperty, expTargetValue);
break;
}
var lambda = Expression.Lambda <Func <TSourceType, bool> >(body, expParameter);
return(lambda);
}
/// <summary>
/// Does a comparison with the given operator to a numeric FITS keyword value.
/// </summary>
/// <param name="fitsKeyword"></param>
/// <param name="value"></param>
/// <param name="comparison"></param>
/// <returns></returns>
public IFitsQueryExpression NumericValueComparison(string fitsKeyword, double value,
NumericComparison comparison)
{
var exprParamType = typeof(FitsSearchResult);
var headerType = typeof(FitsHeaderIndexedRow);
var headerKeywordProps = headerType.GetProperties().Where(p => p.HasAttribute <FitsFieldAttribute>());
var matchingProp = headerKeywordProps.FirstOrDefault(p =>
p.GetCustomAttribute <FitsFieldAttribute>().Name == fitsKeyword);
if (matchingProp == null)
{
throw new FitsDatabaseException($"Cannot add keyword matching for keyword '{fitsKeyword}' to the query, " +
$"this keyword doesn't exist in the indexed keywords");
}
if (matchingProp.PropertyType != typeof(double))
{
throw new FitsDatabaseException($"Cannot add keyword matching for keyword '{fitsKeyword}' to the query, " +
$"the given value is not of type '{matchingProp.PropertyType.Name}'");
}
var targetValue = Expression.Constant(value);
var parameter = Expression.Parameter(exprParamType, "x");
Expression property = Expression.PropertyOrField(parameter, nameof(FitsSearchResult.HeaderData));
property = Expression.PropertyOrField(property, matchingProp.Name);
Expression body = null;
switch (comparison)
{
case NumericComparison.Eq:
body = Expression.Equal(property, targetValue);
break;
case NumericComparison.Gt:
body = Expression.GreaterThan(property, targetValue);
break;
case NumericComparison.Gte:
body = Expression.GreaterThanOrEqual(property, targetValue);
break;
case NumericComparison.Lt:
body = Expression.LessThan(property, targetValue);
break;
case NumericComparison.Lte:
body = Expression.LessThanOrEqual(property, targetValue);
break;
}
var lambda = Expression.Lambda <Func <FitsSearchResult, bool> >(body, parameter);
var expr = new FitsQueryExpression()
{
Expression = lambda
};
return(expr);
}
