object INumExprVisitor <object> .VisitBinExpr(NumBinExpr numBinExpr)
{
this.AppendLine(numBinExpr.Kind.ToString());
this.Push();
numBinExpr.Left.Apply(this);
numBinExpr.Right.Apply(this);
this.Pop();
return(null);
}
public static NumExpr ExpToTree(string exp)
{
exp = exp.SpaceDelite();
NumBinExpr tree = new NumBinExpr();
int BracketCounter = 0, minPrior = 20, indexMinPrior = -1;
for (int i = 0; i < exp.Length; ++i)
{
if (exp[0] == '(' && exp[exp.Length - 1] == ')' && exp.BracketsCanBeDeleted())
{
exp = exp.Remove(exp.Length - 1);
exp = exp.Substring(1);
}
if (exp[i] == '(')
{
++BracketCounter;
}
else if (exp[i] == ')')
{
--BracketCounter;
}
else
{
if (BracketCounter == 0 && !Char.IsLetterOrDigit(exp[i]))
{
int tmpOpPrior = _priorityByChar[exp[i]];
if (minPrior >= _priorityByChar[exp[i]])
{
minPrior = tmpOpPrior;
indexMinPrior = i;
}
}
}
}
if (indexMinPrior != -1)
{
tree.Kind = _opByChar[exp[indexMinPrior]];
tree.Left = ExpToTree(exp.Remove(indexMinPrior));
tree.Right = ExpToTree(exp.Substring(indexMinPrior + 1));
}
else
{
for (int i = 0; i < exp.Length; i++)
{
if (!Char.IsDigit(exp[i]))
{
return(new NumVarExpr(exp));
}
}
return(new NumConstExpr(Int32.Parse(exp)));
}
return(tree);
}
string GetChildStr(NumBinExpr curr, NumExpr child)
{
var bin = child as NumBinExpr;
string result;
if (bin != null && _priorityByOp[curr.Kind] > _priorityByOp[bin.Kind])
{
result = $"({child.Apply(this)})";
}
else
{
result = child.Apply(this);
}
return(result);
}
string INumExprVisitor <string> .VisitBinExpr(NumBinExpr curr)
{
return(string.Join(" ", this.GetChildStr(curr, curr.Left), _strByOp[curr.Kind], this.GetChildStr(curr, curr.Right)));
}
string INumExprVisitor <string> .VisitBinExpr(NumBinExpr numBinExpr)
{
return(numBinExpr.Kind.ToString());
}