private static void _SimplifyIf(BoolExpr result)
{
if (result.IsLeaf())
{
return;
}
if (result.Op == BoolExpr.Bop.If)
{
var nowy = BoolExpr.CreateOr(result.Right, BoolExpr.CreateNot(result.Left));
result.Left = nowy.Left;
result.Right = nowy.Right;
result.Op = nowy.Op;
result.Lit = nowy.Lit;
}
else if (result.Op == BoolExpr.Bop.IfOnlyIf)
{
var nowy = BoolExpr.CreateAnd(BoolExpr.CreateIf(result.Left, result.Right), BoolExpr.CreateIf(result.Right, result.Left));
result.Left = nowy.Left;
result.Right = nowy.Right;
result.Op = nowy.Op;
result.Lit = nowy.Lit;
}
if (result.Left != null)
{
_SimplifyIf(result.Left);
}
if (result.Right != null)
{
_SimplifyIf(result.Right);
}
}
static BoolExpr Make(ref List <Token> .Enumerator polishNotationTokensEnumerator)
{
if (polishNotationTokensEnumerator.Current == null)
{
throw new ArgumentNullException();
}
if (polishNotationTokensEnumerator.Current.Type == Token.TokenType.Literal)
{
var lit = BoolExpr.CreateBoolVar(polishNotationTokensEnumerator.Current.Value);
polishNotationTokensEnumerator.MoveNext();
return(lit);
}
switch (polishNotationTokensEnumerator.Current.Value)
{
case "NOT":
{
polishNotationTokensEnumerator.MoveNext();
var operand = Make(ref polishNotationTokensEnumerator);
return(BoolExpr.CreateNot(operand));
}
case "AND":
{
polishNotationTokensEnumerator.MoveNext();
var left = Make(ref polishNotationTokensEnumerator);
var right = Make(ref polishNotationTokensEnumerator);
return(BoolExpr.CreateAnd(left, right));
}
case "OR":
{
polishNotationTokensEnumerator.MoveNext();
var left = Make(ref polishNotationTokensEnumerator);
var right = Make(ref polishNotationTokensEnumerator);
return(BoolExpr.CreateOr(left, right));
}
case "IF":
{
polishNotationTokensEnumerator.MoveNext();
var left = Make(ref polishNotationTokensEnumerator);
var right = Make(ref polishNotationTokensEnumerator);
return(BoolExpr.CreateIf(left, right));
}
case "IFONLYIF":
{
polishNotationTokensEnumerator.MoveNext();
var left = Make(ref polishNotationTokensEnumerator);
var right = Make(ref polishNotationTokensEnumerator);
return(BoolExpr.CreateIfOnlyIf(left, right));
}
}
return(null);
}
