private static Writer <ListMonoid <Entry>, Entry, List <Maybe <Packet> > > GroupSame(
ListMonoid <Entry> initial,
Func <ListMonoid <Entry>, ListMonoid <Entry>, Writer <ListMonoid <Entry>, Entry, ListMonoid <Entry> > > merge,
List <Packet> packets,
Func <Packet, Writer <ListMonoid <Entry>, Entry, Maybe <Packet> > > fn)
{
if (!packets.Any())
{
return(from _ in WriterEntries.Tell(initial)
select new List <Maybe <Packet> >());
}
var x = packets.First();
var xs = packets.Skip(1).ToList();
return(from tuple in WriterEntries.Return(fn(x).RunWriter)
let result = tuple.Item1
let output = tuple.Item2
let localxs = xs
let localfn = fn
let localinitial = initial
from @new in merge(localinitial, output)
from rest in GroupSame(@new, merge, localxs, localfn)
select Enumerable.Repeat(result, 1).Concat(rest).ToList());
}
private static WriterEntriesEntries MergeEntries(ListMonoid <Entry> e1, ListMonoid <Entry> e2)
{
if (e1.List.Count == 0)
{
return(WriterEntries.Return(e2));
}
if (e2.List.Count == 0)
{
return(WriterEntries.Return(e1));
}
if (e1.List.Count == 1 && e2.List.Count == 1)
{
var n1 = e1.List[0].Count;
var msg1 = e1.List[0].Msg;
var n2 = e2.List[0].Count;
var msg2 = e2.List[0].Msg;
return((msg1 == msg2)
? WriterEntries.Return(new ListMonoid <Entry>(new Entry(n1 + n2, msg1)))
: from _ in WriterEntries.Tell(e1)
select e2);
}
throw new InvalidOperationException("MergeEntries: non-exhaustive patterns");
}
public void MAppendOfXAndMEmptyIsX()
{
// x <> mempty = x
var x = new ListMonoid <int>(1, 2, 3);
var actual = x.MAppend(ListMonoid.MEmpty <int>());
Assert.That(actual.List, Is.EqualTo(x.List));
}
public void MAppendOfMEmptyAndXIsX()
{
// mempty <> x = x
var x = new ListMonoid <int>(1, 2, 3);
var actual = ListMonoid.MEmpty <int>().MAppend(x);
Assert.That(actual.List, Is.EqualTo(x.List));
}
public void MAppend()
{
var lm1 = new ListMonoid <int>(1, 2, 3);
var lm2 = new ListMonoid <int>(4, 5, 6);
var actual = lm1.MAppend(lm2);
Assert.That(actual.List, Is.EqualTo(new[] { 1, 2, 3, 4, 5, 6 }));
}
public void MConcat()
{
var lm1 = new ListMonoid <int>(1, 2, 3);
var lm2 = new ListMonoid <int>(4, 5, 6);
var lm3 = new ListMonoid <int>(7, 8, 9);
var actual = ListMonoid.MConcat(lm1, lm2, lm3);
Assert.That(actual.List, Is.EqualTo(new[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 }));
}
public void MAppendAssociativity()
{
// x <> (y <> z) = (x <> y) <> z
var x = new ListMonoid <int>(1, 2, 3);
var y = new ListMonoid <int>(4, 5, 6);
var z = new ListMonoid <int>(7, 8, 9);
var actual1 = x.MAppend(y.MAppend(z));
var actual2 = x.MAppend(y).MAppend(z);
Assert.That(actual1.List, Is.EqualTo(actual2.List));
}
private static MyWriterUnit TellHelper(string s)
{
var listMonoid = new ListMonoid <string>(s);
return(MyWriter.Tell(listMonoid));
}
public void MEmpty()
{
var actual = ListMonoid.MEmpty <int>();
Assert.That(actual.List, Is.Empty);
}
