private BindingSet Simplify(IList <IExpression> allLhs, int lhsIndex)
{
if (set.Count == 0)
{
return(this);
}
if (lhsIndex >= allLhs.Count)
{
return(this);
}
IExpression lhs = allLhs[lhsIndex];
var groups = GroupBy(lhs);
bool allMatch = true;
BindingSet bindingSet1 = null;
BindingSet newBindingSet = new BindingSet();
BindingSet missing = null;
int count = 0;
foreach (var entry in groups)
{
var bindingSet2 = entry.Value.Simplify(allLhs, lhsIndex + 1);
if (IsMissingExpr(entry.Key))
{
if (bindingSet2.set.Count > 0)
{
missing = bindingSet2;
}
}
else
{
count++;
if (bindingSet1 == null)
{
bindingSet1 = bindingSet2;
}
else if (!BindingSet.AreEqual(bindingSet1, bindingSet2, allLhs, lhsIndex + 1))
{
allMatch = false;
}
}
newBindingSet.set.AddRange(bindingSet2.set);
}
if (count == 2 && allMatch)
{
newBindingSet.set.Clear();
foreach (Dictionary <IExpression, IExpression> dict in bindingSet1.set)
{
var dict2 = Remove(dict, lhs);
if (dict2.Count > 0)
{
newBindingSet.set.Add(dict2);
}
}
if (missing != null)
{
newBindingSet.set.AddRange(missing.set);
}
}
return(newBindingSet);
}
