public static Expression Optimise(Expression expression)
{
if (expression == False)
{
return(expression);
}
var optimiser = new FilterOptimiser();
do
{
optimiser._incomplete = false;
expression = optimiser.VisitAndConvert(expression, nameof(FilterOptimiser));
}while (optimiser._incomplete);
return(expression);
}
public Expression GetConditionOrNull(Expression sourceValue, IMemberMapperData mapperData)
{
var hasFixedValueOperands = false;
var filterExpression = GetFilterExpression(sourceValue, ref hasFixedValueOperands);
if (hasFixedValueOperands)
{
filterExpression = FilterOptimiser.Optimise(filterExpression);
}
if (filterExpression == False)
{
return(null);
}
var condition = GetConditionOrNull(mapperData);
if (condition != null)
{
filterExpression = Expression.AndAlso(condition, filterExpression);
}
return(filterExpression.Negate());
}