internal static IEnumerable <AnalysisProxy> UnionIter(this IEnumerable <AnalysisProxy> items, UnionComparer comparer, out bool wasChanged)
{
#endif
wasChanged = false;
var asSet = items as IAnalysisSet;
if (asSet != null && asSet.Comparer == comparer)
{
return(items);
}
var newItems = new List <AnalysisProxy>();
var anyMerged = true;
while (anyMerged)
{
anyMerged = false;
var matches = new Dictionary <AnalysisProxy, List <AnalysisProxy> >(comparer);
foreach (var ns in items)
{
List <AnalysisProxy> list;
if (matches.TryGetValue(ns, out list))
{
if (list == null)
{
matches[ns] = list = new List <AnalysisProxy>();
}
list.Add(ns);
}
else
{
matches[ns] = null;
}
}
newItems.Clear();
foreach (var keyValue in matches)
{
var item = keyValue.Key;
if (keyValue.Value != null)
{
foreach (var other in keyValue.Value)
{
bool merged;
#if FULL_VALIDATION
Validation.Assert(comparer.Equals(item, other));
#endif
item = comparer.MergeTypes(item, other, out merged);
if (merged)
{
anyMerged = true;
wasChanged = true;
}
}
}
newItems.Add(item);
}
items = newItems;
}
return(items);
}