private static string FormatDecimal(LexoDecimal dec)
{
var formatVal = dec.Format();
var val = new StringBuilder(formatVal);
var partialIndex = formatVal.IndexOf(NumeralSystem.GetRadixPointChar());
var zero = NumeralSystem.ToChar(0);
if (partialIndex < 0)
{
partialIndex = formatVal.Length;
val.Append(NumeralSystem.GetRadixPointChar());
}
while (partialIndex < 6)
{
val.Insert(0, zero);
++partialIndex;
}
while (val[val.Length - 1] == zero)
{
val.Length = val.Length - 1;
}
return(val.ToString());
}
private LexoRank(string value)
{
_value = value;
var parts = _value.Split('|');
Bucket = LexoRankBucket.From(parts[0]);
Decimal = LexoDecimal.Parse(parts[1], NumeralSystem);
}
public static LexoRank From(LexoRankBucket bucket, LexoDecimal dec)
{
if (!dec.GetSystem().Name.Equals(NumeralSystem.Name))
{
throw new LexoException("Expected different system");
}
return(new LexoRank(bucket, dec));
}
private static LexoDecimal CheckMid(LexoDecimal lBound, LexoDecimal rBound, LexoDecimal mid)
{
if (lBound.CompareTo(mid) >= 0)
{
return(Middle(lBound, rBound));
}
return(mid.CompareTo(rBound) >= 0 ? Middle(lBound, rBound) : mid);
}
public LexoRank GenNext()
{
if (IsMin())
{
return(new LexoRank(Bucket, InitialMinDecimal));
}
var ceilInteger = Decimal.Ceil();
var ceilDecimal = LexoDecimal.From(ceilInteger);
var nextDecimal = ceilDecimal.Add(EightDecimal);
if (nextDecimal.CompareTo(MaxDecimal) >= 0)
{
nextDecimal = Between(Decimal, MaxDecimal);
}
return(new LexoRank(Bucket, nextDecimal));
}
public LexoRank GenPrev()
{
if (IsMax())
{
return(new LexoRank(Bucket, InitialMaxDecimal));
}
var floorInteger = Decimal.Floor();
var floorDecimal = LexoDecimal.From(floorInteger);
var nextDecimal = floorDecimal.Subtract(EightDecimal);
if (nextDecimal.CompareTo(MinDecimal) <= 0)
{
nextDecimal = Between(MinDecimal, Decimal);
}
return(new LexoRank(Bucket, nextDecimal));
}
private static LexoDecimal Middle(LexoDecimal left, LexoDecimal right)
{
var sum = left.Add(right);
var mid = sum.Multiply(LexoDecimal.Half(left.GetSystem()));
var scale = left.GetScale() > right.GetScale() ? left.GetScale() : right.GetScale();
if (mid.GetScale() > scale)
{
var roundDown = mid.SetScale(scale, false);
if (roundDown.CompareTo(left) > 0)
{
return(roundDown);
}
var roundUp = mid.SetScale(scale, true);
if (roundUp.CompareTo(right) < 0)
{
return(roundUp);
}
}
return(mid);
}
private LexoRank(LexoRankBucket bucket, LexoDecimal dec)
{
_value = bucket.Format() + "|" + FormatDecimal(dec);
Bucket = bucket;
Decimal = dec;
}
private static LexoDecimal Middle(LexoDecimal lBound, LexoDecimal rBound, LexoDecimal left, LexoDecimal right)
{
var mid = Middle(left, right);
return(CheckMid(lBound, rBound, mid));
}
private static LexoDecimal Between(LexoDecimal oLeft, LexoDecimal oRight)
{
if (oLeft.GetSystem() != oRight.GetSystem())
{
throw new LexoException("Expected same system");
}
var left = oLeft;
var right = oRight;
LexoDecimal nLeft;
if (oLeft.GetScale() < oRight.GetScale())
{
nLeft = oRight.SetScale(oLeft.GetScale(), false);
if (oLeft.CompareTo(nLeft) >= 0)
{
return(Middle(oLeft, oRight));
}
right = nLeft;
}
if (oLeft.GetScale() > right.GetScale())
{
nLeft = oLeft.SetScale(right.GetScale(), true);
if (nLeft.CompareTo(right) >= 0)
{
return(Middle(oLeft, oRight));
}
left = nLeft;
}
LexoDecimal nRight;
for (var scale = left.GetScale(); scale > 0; right = nRight)
{
var nScale1 = scale - 1;
var nLeft1 = left.SetScale(nScale1, true);
nRight = right.SetScale(nScale1, false);
var cmp = nLeft1.CompareTo(nRight);
if (cmp == 0)
{
return(CheckMid(oLeft, oRight, nLeft1));
}
if (nLeft1.CompareTo(nRight) > 0)
{
break;
}
scale = nScale1;
left = nLeft1;
}
var mid = Middle(oLeft, oRight, left, right);
int nScale;
for (var mScale = mid.GetScale(); mScale > 0; mScale = nScale)
{
nScale = mScale - 1;
var nMid = mid.SetScale(nScale);
if (oLeft.CompareTo(nMid) >= 0 || nMid.CompareTo(oRight) >= 0)
{
break;
}
mid = nMid;
}
return(mid);
}
