SLR1 分析表构造代码：改进的 LR0 分析器实现
public class SLRNode
{
public string Left;
public string Right;
public HashSet
//DFA结点
public struct DFA
{
public int from;
public char symbol;
public int to;
public DFA(int from, char symbol, int to)
{
this.from = from;
this.symbol = symbol;
this.to = to;
}
}
//分析表 结点
public class Table
{
public bool error;//是否为ERROR
public char type;//结点类型
public int id;//数值
public Table()
{
this.error = true;
}
public Table(char type, int id)
{
this.type = type;
this.id = id;
this.error = false;
}
}
//分析句子
public class Analyze
{
public List<string> stack_state = new List<string>(100);//记录状态栈
public List<string> stack_symbol = new List<string>(100);//记录符号栈
public List<string> Input_str = new List<string>(100);//记录输入串
public List<string> Tran_pro = new List<string>(100);//记录所用产生式
}
public DFA[] dfa = new DFA[100];
public int Pindex = 0; //dfa数组指针
public Table[][] SLRAna;//分析表
public Analyze Jz;
public bool Success = false;
public List<SLRNode> SLRproNum = new List<SLRNode>(50);//产生式 列表
public List<SLRNode> SLRobjNum = new List<SLRNode>(50);//项目 列表
public List<SLRitemsets> proitemset = new List<SLRitemsets>(100);//项目集合
public List<int> Gy_obj = new List<int>(50);//归约项目序号集合
public List<int> Gy_itemset = new List<int>(50);//含有归约项目的集合的序号 的集合
public List<char> Nchar = new List<char>(50);//非终结符集合
public List<char> Echar = new List<char>(50);//终结符集合
Dictionary<char, HashSet<char>> follow = new Dictionary<char, HashSet<char>>();//非终结符的Follow集
public string RStr = "";
public string RStr_obitemset = "";//输出返回
public string RStr_DFA = "";
public string RStr_ANA = "";
public Table[][] GET_ANA()
{
SLRAnaly();
RStr_ANA += "\r\nSLR1分析表:\r\n ";
int i;
for (i = 0; i < Echar.Count; i++)
{
RStr_ANA += Echar[i].ToString() + " ";
}
for (i = 0; i < Nchar.Count; i++)
{
RStr_ANA += Nchar[i].ToString() + " ";
}
RStr_ANA += "\r\n";
for (i = 0; i < proitemset.Count; i++)
{
RStr_ANA += i.ToString() + " ";
for (int j = 0; j < Echar.Count + Nchar.Count; j++)
{
if (SLRAna[i][j].error)
{
RStr_ANA += " " + " ";
}
else if (i == 1 && j == Echar.Count - 1)
{
RStr_ANA += "AC" + " ";
}
else if (SLRAna[i][j].type != 'N')
{
RStr_ANA += SLRAna[i][j].type.ToString() + SLRAna[i][j].id.ToString() + " ";
}
else
RStr_ANA += SLRAna[i][j].id.ToString() + " ";
}
RStr_ANA += "\r\n";
}
return SLRAna;
}
public void SLRAnaly()
{
//初始化
proitemset.Clear();
Gy_obj.Clear();
Gy_itemset.Clear();
Nchar.Clear();
Echar.Clear();
follow.Clear();
SLRAna = new Table[100][];
for (int i = 0; i < 100; i++)
{
SLRAna[i] = new Table[50];
for (int j = 0; j < 50; j++)
{
SLRAna[i][j] = new Table();
}
}
Pindex = 0;
Success = false;
//构造LR(0)项目集规范族
LR0itemset();
//构造SLR(1)项目集规范族
SLRitemset();
//构造DFA
SLRDFA();
//构造分析表
SLRTable();
}
public void SLRitemset()
{
//初始化
SLRobjNum.Clear();
for (int i = 0; i < proitemset.Count; i++)
{
for (int j = 0; j < proitemset[i].Container.Count; j++)
{
SLRobjNum.Add(new SLRNode(LRobjNum[proitemset[i].Container[j]].Left, LRobjNum[proitemset[i].Container[j]].Right));
}
}
//构造每个项目的First集
First();
//构造每个非终结符的Follow集
Follow();
//构造每个项目的Follow集
for (int i = 0; i < SLRobjNum.Count; i++)
{
FollowOfNode(i);
}
//构造每个项目集的Goto表
for (int i = 0; i < proitemset.Count; i++)
{
for (int j = 0; j < SLRobjNum.Count; j++)
{
if (proitemset[i].Container.Contains(j))
{
if (SLRobjNum[j].Right.IndexOf('.') == SLRobjNum[j].Right.Length - 1)
{
//如果该项目是归约项目，则不需要进行转移
continue;
}
char symbol = SLRobjNum[j].Right[SLRobjNum[j].Right.IndexOf('.') + 1];
if (!Echar.Contains(symbol))
{
//如果该项目的下一个符号是非终结符，则不需要进行转移
continue;
}
int nextitemset = Goto(i, symbol);
if (nextitemset != -1)
{
proitemset[i].Goto[symbol] = nextitemset;
}
}
}
}
}
public void Follow()
{
//初始化
foreach (char c in Nchar)
{
follow[c] = new HashSet<char>();
}
follow[SLRproNum[0].Left].Add('#');
bool changed = true;
while (changed)
{
changed = false;
for (int i = 0; i < SLRproNum.Count; i++)
{
for (int j = 0; j < SLRproNum[i].Right.Length; j++)
{
if (isNonterminal(SLRproNum[i].Right[j]))
{
//如果该符号是非终结符
HashSet<char> tmp = new HashSet<char>();
int k = j + 1;
while (k < SLRproNum[i].Right.Length && SLRproNum[i].Right[k] == '\'')
{
k += 2;
}
if (k ==
原文地址: https://www.cveoy.top/t/topic/f0N0 著作权归作者所有。请勿转载和采集!