public override Digit Remove(int index, Lineage lineage)
{
var whereIsThisIndex = WhereIsThisIndex(index);
#if ASSERTS
Size.AssertUnequal(1);
#endif
TChild res;
switch (whereIsThisIndex)
{
case IN_START:
case IN_MIDDLE_OF_1:
res = First.Remove(index, lineage);
if (res != null && res.IsFragment)
{
TChild left, right;
res.Fuse(Second, out left, out right, lineage);
return(CreateCheckNull(lineage, left, right, Third, Fourth));
}
return(CreateCheckNull(lineage, res, Second, Third, Fourth));
case IN_START_OF_2:
case IN_MIDDLE_OF_2:
res = Second.Remove(index - First.Measure, lineage);
if (res != null && res.IsFragment)
{
TChild left, right;
First.Fuse(res, out left, out right, lineage);
return(CreateCheckNull(lineage, left, right, Third, Fourth));
}
return(CreateCheckNull(lineage, First, res, Third, Fourth));
case IN_START_OF_3:
case IN_MIDDLE_OF_3:
res = Third.Remove(index - First.Measure - Second.Measure, lineage);
if (res != null && res.IsFragment)
{
TChild left, right;
Second.Fuse(res, out left, out right, lineage);
return(CreateCheckNull(lineage, First, left, right, Fourth));
}
return(CreateCheckNull(lineage, First, Second, res, Fourth));
case IN_START_OF_4:
case IN_MIDDLE_OF_4:
res = Fourth.Remove(index - First.Measure - Second.Measure - Third.Measure, lineage);
if (res != null && res.IsFragment)
{
TChild left, right;
Third.Fuse(res, out left, out right, lineage);
return(CreateCheckNull(lineage, First, Second, left, right));
}
return(CreateCheckNull(lineage, First, Second, Third, res));
case IN_END:
case OUTSIDE:
throw ImplErrors.Arg_out_of_range("index", index);
default:
throw ImplErrors.Invalid_execution_path("Checked all index locations.");
}
}
public override void Fuse(Digit other, out Digit first, out Digit last, Lineage lineage)
{
Digit skip;
Fuse(other, out first, out last, out skip, lineage);
}
public override void Insert(int index, Leaf <TValue> leaf, out Digit leftmost, out Digit rightmost, Lineage lineage)
{
#if ASSERTS
leaf.AssertNotNull();
#endif
var whereIsThisIndex = WhereIsThisIndex(index);
TChild myLeftmost;
TChild myRightmost;
leftmost = null;
rightmost = null;
switch (whereIsThisIndex)
{
case IN_START:
case IN_MIDDLE_OF_1:
First.Insert(index, leaf, out myLeftmost, out myRightmost, lineage);
if (Size == 4 && myRightmost != null)
{
leftmost = new Digit(myLeftmost, myRightmost, Second, lineage);
rightmost = MutateOrCreate(Third, Fourth, lineage);
return;
}
leftmost = myRightmost != null
? CreateCheckNull(lineage, myLeftmost, myRightmost, Second, Third)
: CreateCheckNull(lineage, myLeftmost, Second, Third, Fourth);
rightmost = null;
return;
case IN_START_OF_2:
case IN_MIDDLE_OF_2:
Second.Insert(index - First.Measure, leaf, out myLeftmost, out myRightmost, lineage);
if (Size == 4 && myRightmost != null)
{
leftmost = new Digit(First, myLeftmost, myRightmost, lineage);
rightmost = MutateOrCreate(Third, Fourth, lineage);
return;
}
leftmost = myRightmost != null
? CreateCheckNull(lineage, First, myLeftmost, myRightmost, Third)
: CreateCheckNull(lineage, First, myLeftmost, Third, Fourth);
rightmost = null;
return;
case IN_START_OF_3:
case IN_MIDDLE_OF_3:
Third.Insert(index - First.Measure - Second.Measure, leaf, out myLeftmost, out myRightmost, lineage);
if (Size == 4 && myRightmost != null)
{
leftmost = new Digit(First, Second, myLeftmost, lineage);
rightmost = MutateOrCreate(myRightmost, Fourth, lineage);
return;
}
leftmost =
myRightmost != null
? CreateCheckNull(lineage, First, Second, myLeftmost, myRightmost)
: CreateCheckNull(lineage, First, Second, myLeftmost, Fourth);
rightmost = null;
return;
case IN_START_OF_4:
case IN_MIDDLE_OF_4:
Fourth.Insert(index - Measure + Fourth.Measure, leaf, out myLeftmost, out myRightmost, lineage);
if (Size == 4 && myRightmost != null)
{
leftmost = new Digit(First, Second, Third, lineage);
rightmost = MutateOrCreate(myLeftmost, myRightmost, lineage);
return;
}
leftmost = MutateOrCreate(First, Second, Third, myLeftmost, lineage);
rightmost = null;
return;
default:
throw ImplErrors.Invalid_execution_path("");
}
}
private Digit MutateOrCreate(TChild a, TChild b, TChild c, TChild d, Lineage lineage)
{
return(Lineage.AllowMutation(lineage)
? _mutate(a.Measure + b.Measure + c.Measure + d.Measure, 4, a, b, c, d) : new Digit(a, b, c, d, lineage));
}
private Digit MutateOrCreate(TChild a, TChild b, Lineage lineage)
{
return(Lineage.AllowMutation(lineage) ? _mutate(a.Measure + b.Measure, 2, a, b) : new Digit(a, b, lineage));
}
private Digit MutateOrCreate(TChild a, Lineage lineage)
{
return(Lineage.AllowMutation(lineage) ? _mutate(a.Measure, 1, a) : new Digit(a, lineage));
}
public void Fuse(Digit other, out Digit leftmost, out Digit middle, out Digit rightmost, Lineage lineage)
{
#if ASSERTS
other.AssertNotNull();
#endif
var match = (Size << 3) | other.Size;
switch (match)
{
case 1 << 3 | 1:
leftmost = MutateOrCreate(First, other.First, lineage);
rightmost = null;
middle = null;
return;
case 1 << 3 | 2:
leftmost = MutateOrCreate(First, other.First, other.Second, lineage);
rightmost = null;
middle = null;
return;
case 1 << 3 | 3:
leftmost = MutateOrCreate(First, other.First, other.Second, other.Third, lineage);
rightmost = null;
middle = null;
return;
case 1 << 3 | 4:
leftmost = new Digit(First, other.First, lineage);
middle = MutateOrCreate(other.Second, other.Third, other.Fourth, lineage);
rightmost = null;
return;
case 2 << 3 | 1:
leftmost = MutateOrCreate(First, Second, other.First, lineage);
middle = null;
rightmost = null;
return;
case 2 << 3 | 2:
case 2 << 3 | 3:
case 3 << 3 | 2:
case 3 << 3 | 3:
leftmost = this;
middle = other;
rightmost = null;
return;
case 2 << 3 | 4:
leftmost = new Digit(First, Second, other.First, lineage);
middle = MutateOrCreate(other.Second, other.Third, other.Fourth, lineage);
rightmost = null;
return;
case 3 << 3 | 4:
leftmost = this;
middle = new Digit(other.First, other.Second, lineage);
rightmost = other.MutateOrCreate(other.Third, other.Fourth, lineage);
return;
case 3 << 3 | 1:
leftmost = new Digit(First, Second, lineage);
middle = MutateOrCreate(Third, other.First, lineage);
rightmost = null;
return;
case 4 << 3 | 1:
leftmost = new Digit(First, Second, lineage);
middle = MutateOrCreate(Third, Fourth, other.First, lineage);
rightmost = null;
return;
case 4 << 3 | 2:
case 4 << 3 | 3:
leftmost = new Digit(First, Second, lineage);
middle = MutateOrCreate(Third, Fourth, lineage);
rightmost = other;
return;
case 4 << 3 | 4:
leftmost = new Digit(First, Second, Third, lineage);
middle = new Digit(Fourth, other.First, other.Second, lineage);
rightmost = other.MutateOrCreate(other.Third, other.Fourth, lineage);
return;
default:
throw ImplErrors.Invalid_execution_path("Checked all possible size permutations already.");
}
//we should've handled all the cases in the Switch statement. Otherwise, produce this error.
}
//This method is used when we don't know the exact size of the digit we want to create.
public Digit CreateCheckNull(Lineage lineage, TChild item1 = null, TChild item2 = null, TChild item3 = null,
TChild item4 = null)
{
var itemsPresent = item1 != null ? 1 : 0;
itemsPresent |= item2 != null ? 2 : 0;
itemsPresent |= item3 != null ? 4 : 0;
itemsPresent |= item4 != null ? 8 : 0;
Digit res;
switch (itemsPresent)
{
case 0 << 0 | 0 << 1 | 0 << 2 | 0 << 3:
res = null;
break;
case 1 << 0 | 0 << 1 | 0 << 2 | 0 << 3:
res = MutateOrCreate(item1, lineage);
break;
case 0 << 0 | 1 << 1 | 0 << 2 | 0 << 3:
res = MutateOrCreate(item2, lineage);
break;
case 0 << 0 | 0 << 1 | 1 << 2 | 0 << 3:
res = MutateOrCreate(item3, lineage);
break;
case 0 << 0 | 0 << 1 | 0 << 2 | 1 << 3:
res = MutateOrCreate(item4, lineage);
break;
case 1 << 0 | 1 << 1 | 0 << 2 | 0 << 3:
res = MutateOrCreate(item1, item2, lineage);
break;
case 1 << 0 | 1 << 1 | 1 << 2 | 0 << 3:
res = MutateOrCreate(item1, item2, item3, lineage);
break;
case 1 << 0 | 1 << 1 | 1 << 2 | 1 << 3:
res = MutateOrCreate(item1, item2, item3, item4, lineage);
break;
case 0 << 0 | 1 << 1 | 1 << 2 | 0 << 3:
res = MutateOrCreate(item2, item3, lineage);
break;
case 0 << 0 | 1 << 1 | 1 << 2 | 1 << 3:
res = MutateOrCreate(item2, item3, item4, lineage);
break;
case 0 << 0 | 0 << 1 | 1 << 2 | 1 << 3:
res = MutateOrCreate(item3, item4, lineage);
break;
case 1 << 0 | 0 << 1 | 1 << 2 | 0 << 3:
res = MutateOrCreate(item1, item3, lineage);
break;
case 1 << 0 | 0 << 1 | 1 << 2 | 1 << 3:
res = MutateOrCreate(item1, item3, item4, lineage);
break;
case 0 << 0 | 1 << 1 | 0 << 2 | 1 << 3:
res = MutateOrCreate(item2, item4, lineage);
break;
case 1 << 0 | 0 << 1 | 0 << 2 | 1 << 3:
res = MutateOrCreate(item1, item4, lineage);
break;
case 1 << 0 | 1 << 1 | 0 << 2 | 1 << 3:
res = MutateOrCreate(item1, item2, item4, lineage);
break;
default:
throw ImplErrors.Invalid_execution_path("Checked all digit permutations already.");
}
return(res);
}