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 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);
}