/// <summary>
/// Reifies a permutation of length 16 from its canonical scalar representative
/// </summary>
/// <param name="rep">The representative</param>
public static Perm <N16> ToPerm(this Perm16 rep)
{
uint data = (uint)rep;
var dst = Perm <N16> .Alloc();
for (int i = 0, offset = 0; i < dst.Length; i++, offset += 4)
{
dst[i] = (int)BitMask.between(in data, offset, offset + 3);
}
return(dst);
}
public static PermCycle Cycle(this Perm16 src)
{
Span <PermTerm> terms = stackalloc PermTerm[16];
var counter = 0;
for (var i = 0; i < 16; i++)
{
if (src.Includes(i))
{
terms[counter] = new PermTerm(counter, i);
}
counter++;
}
return(new PermCycle(terms.Slice(0, counter)));
}
public static ulong ToScalar(this Perm16 src) => (ulong)src;
public static bool Includes(this Perm16 src, int index) => (((int)src & (4 << index)) != 0);
