public static IVirtualForest <T> Prune <T>(
this IVirtualForest <T> forest,
Func <T, bool> predicate,
PruneOption pruneOption)
{
PruneTreeWalker <T> walker =
new PruneTreeWalker <T>(
forest.TreeWalker,
predicate,
pruneOption);
switch (pruneOption)
{
case PruneOption.PruneDescendants:
return
(forest
.ShallowCopy(
walker,
roots => roots));
case PruneOption.PruneTree:
return
(forest
.ShallowCopy(
walker,
roots => roots.Where(x => !predicate(x))));
default:
throw new NotImplementedException("Whoops! Somebody introduced a new pruning option and forgot to update the switch block.");
}
}
public static IVirtualForest <T> Siblings <T>(this IVirtualForest <T> forest)
{
return
(forest
.ShallowCopy(roots =>
roots
.SelectMany(forest.TreeWalker.GetSiblings)));
}
public static IVirtualForest <T> PrecedingSiblings <T>(this IVirtualForest <T> forest)
{
return
(forest
.ShallowCopy(roots =>
roots
.SelectMany(y =>
forest
.TreeWalker
.GetPrecedingSiblings(y, forest.Comparer))));
}
public static IVirtualForest <T> Siblings <T>(this IVirtualForest <T> forest, IEqualityComparer <T> comparer)
{
return
(forest
.ShallowCopy(roots =>
roots
.SelectMany(x =>
forest
.TreeWalker
.GetSiblings(x, comparer))));
}
public static IVirtualForest <T> FollowingSiblingsAndSelf <T>(this IVirtualForest <T> forest)
{
return
(forest
.ShallowCopy(roots =>
roots
.SelectMany(y =>
forest
.TreeWalker
.GetFollowingSiblingsAndSelf(y, forest.Comparer))));
}
// TODO: what happens when two roots are siblings (have the same parent).
// Should I deduplicate the results? If so how? Using an IEqualityComparer might cause
// issues.
public static IVirtualForest <T> Parents <T>(this IVirtualForest <T> forest)
{
return
(forest
.ShallowCopy(roots =>
roots
.SelectMany(x =>
forest
.TreeWalker
.GetAncestors(x)
.Take(1))));
}
public static IVirtualForest <T> Level <T>(
this IVirtualForest <T> forest,
int depth)
{
return
(forest
.ShallowCopy(roots =>
roots
.SelectMany(x =>
forest
.TreeWalker
.GetLevel(x, depth))));
}
public static IVirtualForest <T> Internals <T>(this IVirtualForest <T> forest)
{
InternalsTreeWalker <T> walker = new InternalsTreeWalker <T>(forest.TreeWalker);
return
(forest
.ShallowCopy(
walker,
roots =>
roots
.Where(x =>
forest
.TreeWalker
.HasChildren(x))));
}
public static IVirtualForest <T> Where <T>(
this IVirtualForest <T> forest,
Func <T, bool> predicate)
{
WhereTreeWalker <T> walker = new WhereTreeWalker <T>(forest.TreeWalker, predicate);
return
(forest
.ShallowCopy(
walker,
roots =>
roots
.SelectMany(x =>
predicate(x) ?
new T[] { x } :
walker.GetDescendants(x, predicate))));
}
public static IVirtualForest <T> Descendants <T>(
this IVirtualForest <T> forest,
Func <T, bool> predicate)
{
return(forest.ShallowCopy(roots => forest.TreeWalker.GetDescendants(roots, predicate)));
}
public static IVirtualForest <T> Children <T>(
this IVirtualForest <T> forest,
T key)
{
return(forest.ShallowCopy(roots => roots.Where(y => forest.Comparer.Equals(key, y))));
}
public static IVirtualForest <T> Children <T>(
this IVirtualForest <T> forest,
Func <T, bool> predicate)
{
return(forest.ShallowCopy(roots => forest.TreeWalker.GetChildren(roots, predicate)));
}
public static IVirtualForest <T> Children <T>(this IVirtualForest <T> forest)
{
return(forest.ShallowCopy(roots => roots.SelectMany(forest.TreeWalker.GetChildren)));
}
public static IVirtualForest <T> ChildAt <T>(
this IVirtualForest <T> forest,
int index)
{
return(forest.ShallowCopy(roots => forest.TreeWalker.GetChildAt(roots, index)));
}
public static IVirtualForest <T> Descendants <T>(
this IVirtualForest <T> forest,
T key)
{
return(forest.ShallowCopy(roots => forest.TreeWalker.GetDescendants(roots, key, forest.Comparer)));
}