internal override PivotsExpression ToPivotsExpression(Dictionary <string, Pivots.Pivot> pivotVsPivotValues, GetChoiceDelegate get_choice_fn)
{
var result = new PivotsExpression();
result.relevant_pivots = new HashSet <string>();
result.relevant_pivots.Add(pivot_name);
result.matching_combinations = new ComparableHashSet <ComparableHashSet <string> >();
if (inverted)
{
foreach (string pivotValue in pivotVsPivotValues[pivot_name].Choices.Keys)
{
if (pivotValue != pivot_choice)
{
ComparableHashSet <string> choice = new ComparableHashSet <string>();
choice.Add(pivotValue);
result.matching_combinations.Add(choice);
}
}
}
else
{
ComparableHashSet <string> choice = new ComparableHashSet <string>();
choice.Add(pivot_choice);
result.matching_combinations.Add(choice);
}
return(result);
}
internal ComparableHashSet <ComparableHashSet <string> > GetExpandedChoices(PivotsExpression expr, HashSet <string> pivots, Dictionary <string, Pivots.Pivot> pivotVsPivotValues)
{
ComparableHashSet <ComparableHashSet <string> > result = expr.matching_combinations;
foreach (string pivot in pivots)
{
if (expr.relevant_pivots.Contains(pivot))
{
continue;
}
ComparableHashSet <ComparableHashSet <string> > new_result = new ComparableHashSet <ComparableHashSet <string> >();
var pivot_choices = pivotVsPivotValues[pivot].Choices.Keys;
foreach (var matching_combination in result)
{
foreach (string pivot_choice in pivot_choices)
{
ComparableHashSet <string> choices = new ComparableHashSet <string>(matching_combination);
choices.Add(pivot_choice);
new_result.Add(choices);
}
}
result = new_result;
}
return(result);
}
internal PivotsExpression Simplify(Dictionary <string, Pivots.Pivot> pivotVsPivotValues)
{
if (invariant)
{
return(this);
}
if (matching_combinations.Count == 0)
{
return(False);
}
int possible_combinations = 1;
foreach (string pivot in relevant_pivots)
{
possible_combinations *= pivotVsPivotValues[pivot].Choices.Keys.Count;
}
if (matching_combinations.Count == possible_combinations)
{
return(True);
}
foreach (string pivot in relevant_pivots)
{
var values = pivotVsPivotValues[pivot].Choices.Keys;
if (matching_combinations.Count % values.Count != 0)
{
continue;
}
int reduced_combinations = matching_combinations.Count / values.Count;
ComparableHashSet <ComparableHashSet <string> > new_combinations = new ComparableHashSet <ComparableHashSet <string> >();
foreach (var combination in matching_combinations)
{
ComparableHashSet <string> reduced_combination = new ComparableHashSet <string>(combination);
reduced_combination.ExceptWith(values);
new_combinations.Add(reduced_combination);
if (new_combinations.Count > reduced_combinations)
{
break;
}
}
if (new_combinations.Count == reduced_combinations)
{
PivotsExpression result = new PivotsExpression();
result.relevant_pivots = new HashSet <string>(relevant_pivots);
result.relevant_pivots.Remove(pivot);
result.matching_combinations = new_combinations;
return(result.Simplify(pivotVsPivotValues));
}
}
return(this);
}
internal override PivotsExpression ToPivotsExpression(Dictionary <string, Pivots.Pivot> pivotVsPivotValues, GetChoiceDelegate get_choice_fn)
{
PivotsExpression left, right;
left = left_child.ToPivotsExpression(pivotVsPivotValues, get_choice_fn);
if (left.invariant)
{
if (left.invariant_result)
{
return(right_child.ToPivotsExpression(pivotVsPivotValues, get_choice_fn));
}
else
{
return(left);
}
}
right = right_child.ToPivotsExpression(pivotVsPivotValues, get_choice_fn);
if (right.invariant)
{
if (right.invariant_result)
{
return(left);
}
else
{
return(right);
}
}
HashSet <string> shared_pivots = new HashSet <string>(left.relevant_pivots);
shared_pivots.IntersectWith(right.relevant_pivots);
if (shared_pivots.Count == left.relevant_pivots.Count)
{
// All pivots are shared, just intersect the sets.
PivotsExpression result = new PivotsExpression();
result.relevant_pivots = left.relevant_pivots;
result.matching_combinations = new ComparableHashSet <ComparableHashSet <string> >(left.matching_combinations);
result.matching_combinations.IntersectWith(right.matching_combinations);
return(result.Simplify(pivotVsPivotValues));
}
if (shared_pivots.Count == 0)
{
// No shared pivots, so do a cross product
PivotsExpression result = new PivotsExpression();
result.relevant_pivots = new HashSet <string>(left.relevant_pivots);
result.relevant_pivots.UnionWith(right.relevant_pivots);
result.matching_combinations = new ComparableHashSet <ComparableHashSet <string> >();
foreach (var left_combination in left.matching_combinations)
{
foreach (var right_combination in right.matching_combinations)
{
ComparableHashSet <string> new_combination = new ComparableHashSet <string>(left_combination);
new_combination.UnionWith(right_combination);
result.matching_combinations.Add(new_combination);
}
}
// It shouldn't be necessary to simplify in this case, as any independent pivots should have been removed already
return(result);
}
HashSet <string> shared_pivot_values = new HashSet <string>();
foreach (string pivot in shared_pivots)
{
shared_pivot_values.UnionWith(pivotVsPivotValues[pivot].Choices.Keys);
}
// Sort by relevant pivot count
if (left.relevant_pivots.Count > right.relevant_pivots.Count)
{
var tmp = left;
left = right;
right = tmp;
}
if (right.relevant_pivots.IsSupersetOf(left.relevant_pivots))
{
// Filter the combintions in right by what's in left.
PivotsExpression result = new PivotsExpression();
result.relevant_pivots = right.relevant_pivots;
result.matching_combinations = new ComparableHashSet <ComparableHashSet <string> >();
foreach (var right_combination in right.matching_combinations)
{
ComparableHashSet <string> reduced_combination = new ComparableHashSet <string>(right_combination);
reduced_combination.IntersectWith(shared_pivot_values);
if (left.matching_combinations.Contains(reduced_combination))
{
result.matching_combinations.Add(right_combination);
}
}
return(result.Simplify(pivotVsPivotValues));
}
else
{
Dictionary <ComparableHashSet <string>, List <ComparableHashSet <string> > > shared_values_to_left_values = new Dictionary <ComparableHashSet <string>, List <ComparableHashSet <string> > >();
foreach (var left_combination in left.matching_combinations)
{
ComparableHashSet <string> shared_values = new ComparableHashSet <string>();
foreach (var value in left_combination)
{
if (shared_pivot_values.Contains(value))
{
shared_values.Add(value);
}
}
List <ComparableHashSet <string> > combination_list;
if (!shared_values_to_left_values.TryGetValue(shared_values, out combination_list))
{
combination_list = shared_values_to_left_values[shared_values] = new List <ComparableHashSet <string> >();
}
combination_list.Add(left_combination);
}
PivotsExpression result = new PivotsExpression();
result.relevant_pivots = new HashSet <string>(left.relevant_pivots);
result.relevant_pivots.UnionWith(right.relevant_pivots);
result.matching_combinations = new ComparableHashSet <ComparableHashSet <string> >();
foreach (var right_combination in right.matching_combinations)
{
ComparableHashSet <string> shared_values = new ComparableHashSet <string>();
foreach (var value in right_combination)
{
if (shared_pivot_values.Contains(value))
{
shared_values.Add(value);
}
}
List <ComparableHashSet <string> > left_combinations;
if (shared_values_to_left_values.TryGetValue(shared_values, out left_combinations))
{
foreach (var left_combination in left_combinations)
{
ComparableHashSet <string> new_combination = new ComparableHashSet <string>(right_combination);
new_combination.UnionWith(left_combination);
result.matching_combinations.Add(new_combination);
}
}
}
return(result.Simplify(pivotVsPivotValues));
}
}