/// <summary>Returns an enumerator that iterates through the collection.</summary>
/// <returns>An enumerator that can be used to iterate through the collection.</returns>
public IEnumerator <T> GetEnumerator()
{
var p = Aspect.Context.Promise <IEnumerable <T> >();
ExpressionHashData hash = null;
if (p is Containing <IEnumerable <T> > || p is Demanding <IEnumerable <T> > )
{
hash = Expression.CalculateHash();
}
try
{
if (p is Containing <IEnumerable <T> > c)
{
var td = c.Get(hash.Hash, Description.Description);
return(td.GetEnumerator());
}
var tran = Aspect.Context.GetQueryTransaction();
var originalEnumerator = CreateNewOriginal(hash?.ModifiedExpression).GetEnumerator();
if (p is NotifyCompleted <IEnumerable <T> > nc)
{
nc.Fulfill(Description.Description);
}
if (p is Demanding <IEnumerable <T> > d)
{
var result = new WrappedEnumerator <T>(originalEnumerator, tran);
result.Demands(d, hash.Hash, Description);
return(result);
}
return(originalEnumerator);
}
catch (Exception ex)
{
if (p is Catching <IEnumerable <T> > d)
{
d.Fulfill(ex, Description.Description);
}
throw;
}
}
/// <summary>Executes the strongly-typed query represented by a specified expression tree.</summary>
/// <param name="expression">An expression tree that represents a LINQ query.</param>
/// <typeparam name="TResult">The type of the value that results from executing the query.</typeparam>
/// <returns>The value that results from executing the specified query.</returns>
public TResult Execute <TResult>(Expression expression)
{
var p = Aspect.Context.Promise <TResult>();
ExpressionHashData hash = null;
if (p is Containing <TResult> || p is Demanding <TResult> )
{
hash = expression.CalculateHash();
}
try
{
if (p is Containing <TResult> c)
{
return(c.Get(hash.Hash, Description.Description));
}
var result = Original.Execute <TResult>(hash == null ? expression : hash.ModifiedExpression);
if (p is NotifyCompleted <TResult> nc)
{
nc.Fulfill(Description.Description);
}
if (p is Demanding <TResult> d)
{
d.Fulfill(result, hash.Hash, Description.Description);
}
return(result);
}
catch (Exception ex)
{
if (p is Catching <TResult> d)
{
d.Fulfill(ex, Description.Description);
}
throw;
}
}
