static ZipList <ZipList <T> > Transpose2 <T>(this ZipList <ZipList <T> > matrix)
{
if (matrix.IsEmpty)
{
return(ZipList.Pure(ZipList.Empty <T>()));
}
else
{
return
(from m in matrix.Value
join r in Transpose(matrix.Tail.Value) on 1 equals 1
select ZipList.Cons <T>(m, new Lazy <ZipList <T> >(() => r)));
}
}
// The transpose function implemented using the
// lazy functional list declared above
#region Alternative implementation of Transpose
static ZipList <ZipList <T> > Transpose <T>(this ZipList <ZipList <T> > matrix)
{
if (matrix.IsEmpty)
{
return(ZipList.Pure(ZipList.Empty <T>()));
}
else
{
return
(ZipList.
PureFunc((T v, ZipList <T> l) => ZipList.Cons(v, new Lazy <ZipList <T> >(() => l))).
Apply(matrix.Value).
Apply(Transpose(matrix.Tail.Value)));
}
}
// Similar demos as those from blog post, but based
// on the functional lazy list implementation
#region Alternative demos
private static void ZipListDemos()
{
var nums1 = ZipList.Range(0, 10);
var nums2 = ZipList.Range(0, 10);
var q =
from n in nums1
join m in nums2 on 1 equals 1
select n + m;
foreach (var z in q.AsEnumerable())
{
Console.Write("{0}, ", z);
}
Console.WriteLine();
Console.WriteLine();
var matrix = new[] {
new[] { 1, 2, 3 },
new[] { 10, 20, 30 },
new[] { 100, 200, 300 }
};
var zipMatrix = matrix.Select(ZipList.ToZipList).ToZipList();
var transposed = zipMatrix.Transpose2();
foreach (var a in transposed.AsEnumerable())
{
foreach (var b in a.AsEnumerable())
{
Console.Write("{0}, ", b);
}
Console.WriteLine();
}
}
