public static IRoseTree <string, FileInfo> moveTo(string destination, IRoseTree <string, PhotoFile> t)
{
string dirNameOf(DateTime dt) => dt.ToString("yyyy-MM");
Dictionary <string, IEnumerable <FileInfo> > groupByDir(Dictionary <string, IEnumerable <FileInfo> > m, PhotoFile pf)
{
var key = dirNameOf(pf.TakenOn);
var exists = m.TryGetValue(key, out var item);
IEnumerable <FileInfo> dir;
if (exists)
{
dir = item;
m[key] = dir.Concat(new List <FileInfo> {
pf.File
});
}
else
{
m.Add(key, new List <FileInfo> {
pf.File
});
}
return(m);
}
List <IRoseTree <string, FileInfo> > addDir(IEnumerable <IRoseTree <string, FileInfo> > dirs, KeyValuePair <string, IEnumerable <FileInfo> > pair)
{
var name = pair.Key;
var files = pair.Value;
var branches = files.Select(f => RoseTree.Leaf <string, FileInfo>(f));
return(dirs.Concat(new[] { RoseTree.Node(name, branches.ToArray()) }).ToList());
}
var m = t.Fold((acc, x) => groupByDir(acc, x), new Dictionary <string, IEnumerable <FileInfo> >());
var dirs = m.Aggregate(new List <IRoseTree <string, FileInfo> >(), addDir);
return(RoseTree.Node(destination, dirs.ToArray()));
}
public void test()
{
IRoseTree <string, Command> editMenu =
from name in editMenuTemplate
select commandStore.Lookup(name).GetOrElse(new Command(name));
Maybe <Command> find;
using StringWriter sw = new StringWriter();
Console.SetOut(sw);
find = editMenu.Find(e => e.Name == "Find");
var findAll = editMenu.FindAll(e => e.Name == "Find" || e.Name == "Copy");
var concat = editMenu.Fold((acc, c) => acc + c.Name, "");
find.Match(Nothing: () => { }, Just: c => c.Execute());
Assert.Equal($"Find\r\n", sw.ToString());
}
