/// <summary>
/// Returns a set containing all the types in <paramref name="ns" />
/// after merging using the specified <see cref="UnionComparer" />. For
/// large sets, this operation may require significant time and memory.
/// The returned set is always a copy of the original.
/// </summary>
/// <param name="ns">The namespaces to contain in the set.</param>
/// <param name="comparer">The comparer to use for the set.</param>
internal static IAnalysisSet CreateUnion(IEnumerable <AnalysisProxy> ns, UnionComparer comparer)
{
bool dummy;
// TODO: Replace Trim() call with more intelligent enumeration.
return(new AnalysisSetDetails.AnalysisHashSet(ns.UnionIter(comparer, out dummy), comparer).Trim());
}
/// <summary>
/// Returns <paramref name="set"/> with the specified comparer. If the
/// comparer does not need to be changed, <paramref name="set"/> is
/// returned unmodified.
/// </summary>
/// <param name="set">The set to convert to a union.</param>
/// <param name="comparer">The comparer to use for the set.</param>
/// <param name="wasChanged">Returns True if the contents of the
/// returned set are different to <paramref name="set"/>.</param>
internal static IAnalysisSet AsUnion(this IAnalysisSet set, UnionComparer comparer, out bool wasChanged)
{
if ((set is AnalysisSetDetails.AnalysisSetOneUnion ||
set is AnalysisSetDetails.AnalysisSetTwoUnion ||
set is AnalysisSetDetails.AnalysisSetEmptyUnion ||
set is AnalysisSetDetails.AnalysisHashSet) &&
set.Comparer == comparer)
{
wasChanged = false;
return(set);
}
wasChanged = true;
var ns = set as AnalysisProxy;
if (ns != null)
{
return(CreateUnion(ns, comparer));
}
var ns2 = set as AnalysisSetDetails.AnalysisSetTwoObject;
if (ns2 != null)
{
if (ns2.Value1 == null)
{
if (ns2.Value2 == null)
{
wasChanged = false;
return(AnalysisSetEmptyUnion.Instances[comparer.Strength]);
}
wasChanged = false;
return(new AnalysisSetOneUnion(ns2.Value2, comparer));
}
else if (ns2.Value2 == null)
{
wasChanged = false;
return(new AnalysisSetOneUnion(ns2.Value1, comparer));
}
if (comparer.Equals(ns2.Value1, ns2.Value2))
{
bool dummy;
return(new AnalysisSetDetails.AnalysisSetOneUnion(comparer.MergeTypes(ns2.Value1, ns2.Value2, out dummy), comparer));
}
else
{
return(new AnalysisSetDetails.AnalysisSetTwoUnion(ns2.Value1, ns2.Value2, comparer));
}
}
return(new AnalysisSetDetails.AnalysisHashSet(set, comparer));
}
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);
}
private static IEnumerable <AnalysisWrapper> UnionIterInternal(IEnumerable <AnalysisWrapper> items, UnionComparer comparer, out bool wasChanged)
{
/// <summary>
/// Merges the provided sequence using the specified <see
/// cref="UnionComparer"/>.
/// </summary>
#if FULL_VALIDATION
internal static IEnumerable <AnalysisWrapper> UnionIter(this IEnumerable <AnalysisWrapper> items, UnionComparer comparer, out bool wasChanged)
{
var originalItems = items.ToList();
var newItems = UnionIterInternal(items, comparer, out wasChanged).ToList();
Validation.Assert(newItems.Count <= originalItems.Count);
if (wasChanged)
{
Validation.Assert(newItems.Count < originalItems.Count);
foreach (var x in newItems)
{
foreach (var y in newItems)
{
if (object.ReferenceEquals(x, y))
{
continue;
}
Validation.Assert(!comparer.Equals(x, y));
Validation.Assert(!comparer.Equals(y, x));
}
}
}
return(newItems);
}
/// <summary>
/// Returns a set containing only <paramref name="ns" /> that uses the
/// specified <see cref="UnionComparer" />.
///
/// This is different to casting from <see cref="AnalysisProxy" /> to <see
/// cref="IAnalysisSet" />, because the implementation in <see
/// cref="AnalysisProxy" /> always uses <see cref="ObjectComparer" />.
/// </summary>
/// <param name="ns">The namespace to contain in the set.</param>
/// <param name="comparer">The comparer to use for the set.</param>
internal static IAnalysisSet CreateUnion(AnalysisProxy ns, UnionComparer comparer)
{
return(new AnalysisSetDetails.AnalysisSetOneUnion(ns, comparer));
}
/// <summary>
/// Returns an empty set that uses the specified <see
/// cref="UnionComparer" />.
/// </summary>
/// <param name="comparer">The comparer to use for the set.</param>
internal static IAnalysisSet CreateUnion(UnionComparer comparer)
{
return(AnalysisSetDetails.AnalysisSetEmptyUnion.Instances[comparer.Strength]);
}