public void fchar_Vn(Production p)
{
char key = p.Left;
char fchar = p.Right[0];
foreach (char c in FirstSets[fchar])
{
if (c != Empty)
{
Changed |= FirstSets[key].Add(c);
}
}
int i;
for (i = 0; i < p.Right.Length; ++i)
{
char ch = p.Right[i];
if (cfg.isVn(ch) && FirstSets[fchar].Contains(Empty))
{
foreach (char c in FirstSets[ch])
{
if (c != Empty)
{
Changed |= FirstSets[key].Add(c);
}
}
}
else
{
break;
}
}
if (i == p.Right.Length)
{
Changed |= FirstSets[key].Add(Empty);
}
}
public Item(Production p, int i, Char s)
{
Production = p;
Index = i;
if (p.Right == System.Configuration.ConfigurationManager.AppSettings["Empty"][0].ToString())
{
Production.Right = "";
Index = 0;
}
Symbol = s;
}
public void AnalyseProduction(Production p)
{
char key = p.Left;
char fchar = p.Right[0];
if (cfg.isVn(fchar))
{
fchar_Vn(p);
}
else
{
Changed |= FirstSets[key].Add(fchar);
}
}
public void Build(string[] Input)
{
try
{
Start = Input[0][0];
foreach (string s in Input)
{
if (s == string.Empty)
{
continue;
}
string[] tp = s.Split(new String[] { "→" }, StringSplitOptions.None);
if (tp.Length != 2)
{
throw new Exception("产生式应该有且仅有一个→");
}
if (tp[0].Length != 1 || !isVn(tp[0][0]))
{
throw new Exception("产生式左边应该是一个非终结符");
}
char left = tp[0][0];
char empty= System.Configuration.ConfigurationManager.AppSettings["Empty"][0];
Vn.Add(left);
string[] right = tp[1].Split('|');
for (int i = 0; i < right.Count(); ++i)
{
string part = right[i];
foreach (char c in part)
{
if (isVn(c))
{
Vn.Add(c);
}
else
{
Vt.Add(c);
}
}
Production p = new Production(left,part);
if (!ProductionsMap.ContainsKey(p))
{
Productions.Add(p);
ProductionsMap.Add(p, ProductionsMap.Count() + 1);
_ProductionsMap.Add(_ProductionsMap.Count() + 1, p);
}
}
}
}
catch (Exception )
{
throw new Exception("输入不合法\n");
}
}
