public static IEnumerable <L> FindAll <N, L>(this IRoseTree <N, L> source, Func <L, bool> f)
=> source.Match(
node: (x, xs) => xs.ToList().Aggregate(new List <L>(), (acc, t) => acc.Concat(t.FindAll(f)).ToList()),
leaf: l => f(l) ? new List <L>()
{
l
} : new List <L>()
);
public static TResult Cata <N, L, TResult>(
this IRoseTree <N, L> tree,
Func <N, IEnumerable <TResult>, TResult> node,
Func <L, TResult> leaf)
=> tree.Match(
node: (n, branches) => node(n, branches.Select(t => t.Cata(node, leaf))),
leaf: leaf
);
public static TResult Fold <N, L, TResult>(
this IRoseTree <N, L> source,
Func <TResult, L, TResult> g,
TResult acc
)
=> source.Match(
node: (x, xs) => xs.ToList().Aggregate(acc, (ac, t) => t.Fold(g, ac)),
leaf: l => g(acc, l)
);
public static IRoseTree <string, Move> calculateMoves(IRoseTree <string, FileInfo> tree)
{
FileInfo ReplaceDirectory(FileInfo f, string d)
=> new FileInfo(Path.Combine(d, f.Name));
IRoseTree <string, Move> imp(string path, IRoseTree <string, FileInfo> tree)
=> tree.Match(
leaf: l => RoseTree.Leaf <string, Move>(new Move {
Source = l, Destination = ReplaceDirectory(l, path)
}),
node: (x, xs) =>
{
var newPath = Path.Combine(path, x);
return(RoseTree.Node <string, Move>(newPath, xs.Select(t => imp(newPath, t)).ToArray()));
});
return(imp("", tree));
}
public static IChurchBoolean IsLeaf <N, L>(this IRoseTree <N, L> source)
=> source.Match <IChurchBoolean>(
node: (_, __) => new ChurchFalse(),
leaf: _ => new ChurchTrue());
