SLR1 分析器实现：函数代码与调用示例
以下是 SLR1 分析器的函数代码和调用示例，详细解释了每个函数的作用和实现细节。/n/ncsharp/nclass SLR/n{/n //产生式结点类/n public class SLRNode/n {/n public string Left;/n public string Right;/n public SLRNode(string Left, string Right)/n {/n this.Left = Left;/n this.Right = Right;/n }/n }/n //项目集类/n public class SLRitemsets/n {/n public List<int> Container = new List<int>(100);/n //记录项目在项目集合中的序号/n }/n/n //DFA结点/n public struct DFA/n {/n public int from;/n public char symbol;/n public int to;/n public DFA(int from, char symbol, int to)/n {/n this.from = from;/n this.symbol = symbol;/n this.to = to;/n }/n }/n/n //分析表 结点/n public class Table/n {/n public bool error;//是否为ERROR/n public char type;//结点类型/n public int id;//数值/n public Table()/n {/n this.error = true;/n }/n public Table(char type, int id)/n {/n this.type = type;/n this.id = id;/n this.error = false;/n }/n }/n/n //分析句子/n public class Analyze/n {/n public List<string> stack_state = new List<string>(100);//记录状态栈/n public List<string> stack_symbol = new List<string>(100);//记录符号栈/n public List<string> Input_str = new List<string>(100);//记录输入串/n public List<string> Tran_pro = new List<string>(100);//记录所用产生式/n }/n/n public DFA[] dfa = new DFA[100];/n public int Pindex = 0; //dfa数组指针/n public Table[][] SLRAna;//分析表/n public Analyze Jz;/n public bool Success = false;/n public List<SLRNode> SLRproNum = new List<SLRNode>(50);//产生式 列表/n public List<SLRNode> SLRobjNum = new List<SLRNode>(50);//项目 列表/n public List<SLRitemsets> proitemset = new List<SLRitemsets>(100);//项目集合/n public List<int> Gy_obj = new List<int>(50);//归约项目序号集合/n public List<int> Gy_itemset = new List<int>(50);//含有归约项目的集合的序号 的集合/n public List<char> Nchar = new List<char>(50);//非终结符集合/n public List<char> Echar = new List<char>(50);//终结符集合/n/n Dictionary<char, HashSet<char>> follow = new Dictionary<char, HashSet<char>>();//非终结符的Follow集/n/n public string RStr = '';/n public string RStr_obitemset = '';//输出返回/n public string RStr_DFA = '';/n public string RStr_ANA = '';/n/n public void Buildprod(string str)/n {/n SLRNode Lr;/n int i = 0;/n string left = '';/n string right = '';/n left += 'S';/n right += str[0];/n Lr = new SLRNode(left, right);//拓广文法开始/n SLRproNum.Add(Lr);/n while (i < str.Length)/n {/n left = right = '';//还原/n int j = i;/n while (i < str.Length && str[i] != '//r' && str[i] != '//n')//换行符‘//r//n’/n {/n if (str[i] == ' ')/n {/n i++;/n continue;/n }/n if (str[i] == '|') // 遇到'|'可构造一条产生式/n {/n Lr = new SLRNode(left, right);/n SLRproNum.Add(Lr);/n right = ''; //产生式左边相同 右边重新积累/n i++; //跳过'|'/n continue;/n }/n if ((i - j) == 0)/n {/n if (!exist(Nchar, str[i]))//如果非终结符集合中不存在str[i],加入Nchar 产生式左边 只有非终结符 不必判断终结符/n Nchar.Add(str[i]);/n left += str[i++];/n }/n else if (i - j <= 2)/n i++;/n else/n {/n if (isFinalsymbol(str[i]) && !exist(Nchar, str[i]))//如果非终结符集合中不存在str[i],加入Nchar isfinalsymbol 非终结符返回T 终结符返回F/n Nchar.Add(str[i]);/n else if (!isFinalsymbol(str[i]) && !exist(Echar, str[i]))//产生式右边 需要判断终结符/n Echar.Add(str[i]);/n right += str[i++];/n }/n }//while/n/n i++;//跳过换行符/n if (left != '' && right != '')/n {/n Lr = new SLRNode(left, right);//构造每一行最后一个产生式，不存在'|'时就是该行产生式本身/n SLRproNum.Add(Lr);/n }/n }//while/n Echar.Add('#');/n/n //构造项目 对产生式集合SLRproNum中的所有产生式都循环插'.'/n SLRNode Lobj;/n for (i = 0; i < SLRproNum.Count; i++)/n {/n left = '';/n right = '';/n for (int j = 0; j <= SLRproNum[i].Right.Length; j++)//j可以等于length 项目共length+1个/n {/n left = SLRproNum[i].Left;/n right = CreObj(SLRproNum[i].Right, j);//在第j个位置插入'.'/n if (j == SLRproNum[i].Right.Length && SLRobjNum.Count != 1)/n {/n //在产生式最后的位置插入. 即为归约项目 项目集中1号位置为接受项目/n Gy_obj.Add(SLRobjNum.Count);//归约项目在项目集中的序号 不用+1 本身就是从0开始的/n }/n Lobj = new SLRNode(left, right);/n SLRobjNum.Add(Lobj);/n left = '';//还原/n right = '';/n }/n }/n Creteitemsets();//项目集/n RStr_obitemset += '//r//n项目集构建：//r//n';/n for (int j = 0; j < proitemset.Count; j++)/n {/n RStr_obitemset += 'I' + j.ToString() + ':' + '//r//n';/n for (i = 0; i < proitemset[j].Container.Count; i++)/n {/n RStr_obitemset += SLRobjNum[proitemset[j].Container[i]].Left.ToString() + /'->/' + SLRobjNum[proitemset[j].Container[i]].Right.ToString() + '//r//n';/n }/n }/n //return RStr_obitemset;/n }/n/n public void Creteitemsets()//项目集构建/n {/n /n }/n/npublic Table[][] GET_ANA(){}//获取LR0分析表/n/npublic void SLRAnaly(){}//构造分析表/n/npublic void sen_Analyze(string text){}//分析句子/n/n/n /n /n/n}/n/n/n## 补充函数代码：/n/n1. CreObj 函数：在产生式右边的第 j 个位置插入 '.'。/n/ncsharp/nprivate string CreObj(string str, int j)/n{/n string newstr = '';/n for (int i = 0; i < str.Length; i++)/n {/n if (i == j)/n newstr += '.';/n newstr += str[i];/n }/n if (j == str.Length)/n newstr += '.';/n return newstr;/n}/n/n/n2. exist 函数：判断字符集合中是否存在某个字符。/n/ncsharp/nprivate bool exist(List<char> list, char ch)/n{/n foreach (char c in list)/n {/n if (c == ch)/n return true;/n }/n return false;/n}/n/n/n3. isFinalsymbol 函数：判断某个字符是否为终结符。/n/ncsharp/nprivate bool isFinalsymbol(char ch)/n{/n if (ch >= 'a' && ch <= 'z')/n return true;/n if (ch >= 'A' && ch <= 'Z')/n return false;/n return false;/n}/n/n/n4. Closure 函数：计算项目集的闭包。/n/ncsharp/nprivate SLRitemsets Closure(SLRitemsets itemset)/n{/n SLRitemsets newitemset = new SLRitemsets();/n newitemset.Container.AddRange(itemset.Container);//将原项目集加入新项目集/n bool flag = true;//标记是否需要继续扩展/n while (flag)/n {/n flag = false;/n for (int i = 0; i < newitemset.Container.Count; i++)/n {/n int index = newitemset.Container[i];//获取项目在SLRobjNum中的序号/n if (SLRobjNum[index].Right.IndexOf('.') < SLRobjNum[index].Right.Length - 1)//判断'.'是否在产生式最后一个位置/n {/n char X = SLRobjNum[index].Right[SLRobjNum[index].Right.IndexOf('.') + 1];//获取'.'后面的符号/n if (!isFinalsymbol(X))//如果是非终结符/n {/n foreach (SLRNode node in SLRobjNum)//在SLRobjNum中查找以X为左部的产生式/n {/n if (node.Left[0] == X)/n {/n string newright = CreObj(node.Right, 0);//产生新的项目/n SLRNode newnode = new SLRNode(X.ToString(), newright);/n if (!exist(newitemset.Container, SLRobjNum.IndexOf(newnode)))//如果新项目不在项目集中，则加入/n {/n newitemset.Container.Add(SLRobjNum.IndexOf(newnode));/n flag = true;//标记需要继续扩展/n }/n }/n }/n }/n }/n }/n }/n return newitemset;/n}/n/n/n5. Goto 函数：计算项目集的 Goto 集。/n/ncsharp/nprivate SLRitemsets Goto(SLRitemsets itemset, char X)/n{/n SLRitemsets newitemset = new SLRitemsets();/n foreach (int i in itemset.Container)/n {/n if (SLRobjNum[i].Right.IndexOf('.') < SLRobjNum[i].Right.Length - 1)//判断'.'是否在产生式最后一个位置/n {/n char Y = SLRobjNum[i].Right[SLRobjNum[i].Right.IndexOf('.') + 1];//获取'.'后面的符号/n if (Y == X)//如果符号为X，则将'.'向右移动一位/n {/n string newright = CreObj(SLRobjNum[i].Right, SLRobjNum[i].Right.IndexOf('.') + 1);/n SLRNode newnode = new SLRNode(SLRobjNum[i].Left, newright);/n newitemset.Container.Add(SLRobjNum.IndexOf(newnode));//加入新的项目/n }/n }/n }/n return Closure(newitemset);//计算新项目集的闭包/n}/n/n/n6. GET_ANA 函数：获取 SLR1 分析表。/n/ncsharp/npublic Table[][] GET_ANA()/n{/n SLRAnaly();//构造分析表/n RStr_ANA += '//r//nSLR1分析表：//r//n';/n Table[][] Ana = new Table[proitemset.Count][];/n for (int i = 0; i < proitemset.Count; i++)/n {/n Ana[i] = new Table[Echar.Count + Nchar.Count];//初始化分析表/n for (int j = 0; j < Echar.Count; j++)/n Ana[i][j] = new Table();/n for (int j = 0; j < Nchar.Count; j++)/n Ana[i][j + Echar.Count] = new Table();/n foreach (int index in proitemset[i].Container)//遍历项目集中的所有项目/n {/n if (SLRobjNum[index].Right.IndexOf('.') < SLRobjNum[index].Right.Length - 1)//如果'.'不在产生式最后一个位置/n {/n char X = SLRobjNum[index].Right[SLRobjNum[index].Right.IndexOf('.') + 1];//获取'.'后面的符号/n if (isFinalsymbol(X))//如果是终结符/n {/n int j = Echar.IndexOf(X);/n int k = proitemset.IndexOf(Goto(proitemset[i], X));/n Ana[i][j] = new Table('S', k);//移进/n }/n }/n else//如果'.'在产生式最后一个位置/n {/n if (SLRobjNum[index].Left == /'S'/')//如果产生式为拓广文法的开始符号/n {/n int j = Echar.IndexOf('#');/n Ana[i][j] = new Table('A', 0);//接受/n }/n else//否则为归约项目/n {/n int j = Nchar.IndexOf(SLRobjNum[index].Left[0]);//获取产生式左部的非终结符在Nchar中的位置/n foreach (int k in Gy_obj)//遍历所有归约项目/n {/n if (SLRobjNum[k].Left == SLRobjNum[index].Left && SLRobjNum[k].Right.Length == SLRobjNum[index].Right.Length)//如果左部相同且长度相同/n {/n bool flag = true;/n for (int m = 0; m < SLRobjNum[k].Right.Length; m++)//判断右部是否相同/n {/n if (SLRobjNum[k].Right[m] != SLRobjNum[index].Right[m])/n {/n flag = false;/n break;/n }/n }/n if (flag)//如果右部相同/n {/n Ana[i][j + Echar.Count] = new Table('R', k);//归约/n break;/n }/n }/n }/n }/n }/n }/n for (int j = 0; j < Echar.Count + Nchar.Count; j++)/n {/n if (!Ana[i][j].error)/n {/n if (Ana[i][j].type == 'S')/n RStr_ANA += /'S/' + Ana[i][j].id.ToString() + /'//t/';/n else if (Ana[i][j].type == 'R')/n RStr_ANA += /'R/' + Ana[i][j].id.ToString() + /'//t/';/n else if (Ana[i][j].type == 'A')/n RStr_ANA += /'ACC//t/';/n }/n else/n RStr_ANA += /'//t/';/n }/n RStr_ANA += /'//r//n/';/n }/n return Ana;/n}/n/n/n7. SLRAnaly 函数：构造 SLR1 分析表。/n/n```csharp/npublic void SLRAnaly()/n{/n proitemset.Add(Closure(new SLRitemsets() { Container = new List
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