/// <summary>
/// Compile the single item if it is possible to compile.
/// It concerns those <see cref="ExpressionPart"/>s items which returns expression in <seealso cref="ExpressionPart.GetExpression(EvaluationContext, string, ref ExpressionData)"/>.
/// </summary>
/// <param name="context">The context of evaluation.</param>
/// <param name="expressionTree">The expression tree.</param>
protected virtual bool CompileSingleItem(EvaluationContext context, IList <ProcessedItem> expressionTree)
{
// compile single item
return(ReverseLoop(expressionTree, i =>
{
ProcessedItem item = expressionTree[i];
if (item.ItemType != null)
{
IExpressionPart obj = GetObject(item.ItemType);
ExpressionData data = new ExpressionData();
Expression compiled = obj.GetExpression(context, item.Content, ref data);
if (compiled != null)
{
ProcessedItem newItem = ProcessedItem.Create(compiled);
expressionTree.RemoveAt(i);
expressionTree.Insert(i, newItem);
return true;
}
else if (data.TypeToCast != null)
{
ProcessedItem newItem = ProcessedItem.CreateCast(data.TypeToCast);
expressionTree.RemoveAt(i);
expressionTree.Insert(i, newItem);
return true;
}
}
return false;
}));
}
public static Expression <Func <T, TResult> > GetExpression <T, TResult>(this IExpressionPart filterPart, IDictionary <string, ParameterExpression> parameters, string parameterName)
=> (Expression <Func <T, TResult> >)filterPart.GetExpression
(
typeof(T),
typeof(TResult),
parameters,
parameterName
);
