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()); }