private static BoundQuery ToDisjunctiveNormalForm(BoundQuery node)
{
if (node is BoundNegatedQuery negated)
{
return(ToDisjunctiveNormalForm(Negate(negated.Query)));
}
if (node is BoundOrQuery or)
{
var left = ToDisjunctiveNormalForm(or.Left);
var right = ToDisjunctiveNormalForm(or.Right);
if (ReferenceEquals(left, or.Left) &&
ReferenceEquals(right, or.Right))
{
return(node);
}
return(new BoundOrQuery(left, right));
}
if (node is BoundAndQuery and)
{
var left = ToDisjunctiveNormalForm(and.Left);
var right = ToDisjunctiveNormalForm(and.Right);
// (A OR B) AND C -> (A AND C) OR (B AND C)
if (left is BoundOrQuery leftOr)
{
var a = leftOr.Left;
var b = leftOr.Right;
var c = right;
return(new BoundOrQuery(
ToDisjunctiveNormalForm(new BoundAndQuery(a, c)),
ToDisjunctiveNormalForm(new BoundAndQuery(b, c))
));
}
// A AND (B OR C) -> (A AND B) OR (A AND C)
if (right is BoundOrQuery rightOr)
{
var a = left;
var b = rightOr.Left;
var c = rightOr.Right;
return(new BoundOrQuery(
ToDisjunctiveNormalForm(new BoundAndQuery(a, b)),
ToDisjunctiveNormalForm(new BoundAndQuery(a, c))
));
}
return(new BoundAndQuery(left, right));
}
return(node);
}
static void Walk(IndentedTextWriter writer, BoundQuery node)
{
switch (node)
{
case BoundKevValueQuery kevValue:
writer.WriteLine($"{(kevValue.IsNegated ? "-" : "")}{kevValue.Key}:{kevValue.Value}");
break;
case BoundTextQuery text:
writer.WriteLine($"{(text.IsNegated ? "-" : "")}{text.Text}");
break;
case BoundNegatedQuery negated:
writer.WriteLine("NOT");
writer.Indent++;
Walk(writer, negated.Query);
writer.Indent--;
break;
case BoundAndQuery and:
writer.WriteLine("AND");
writer.Indent++;
Walk(writer, and.Left);
Walk(writer, and.Right);
writer.Indent--;
break;
case BoundOrQuery or:
writer.WriteLine("OR");
writer.Indent++;
Walk(writer, or.Left);
Walk(writer, or.Right);
writer.Indent--;
break;
default:
throw new Exception($"Unexpected node {node.GetType()}");
}
}
private static BoundQuery Negate(BoundQuery node)
{
switch (node)
{
case BoundKevValueQuery kevValue:
return(NegateKevValueExpression(kevValue));
case BoundTextQuery text:
return(NegateTextExpression(text));
case BoundNegatedQuery negated:
return(NegateNegatedExpression(negated));
case BoundAndQuery and:
return(NegateAndExpression(and));
case BoundOrQuery or:
return(NegateOrExpression(or));
default:
throw new Exception($"Unexpected node {node.GetType()}");
}
}
