采用实验1的简单语言，设计并实现含多条简单赋值语句的语法分析程序，要求采用算符优先的分析算法。   

注意与实验1、2的衔接。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace SyntaxAnalysis {struct Error {Word word;string text;}class SyntaxAnalysis {WordPicker wordPicker = new WordPicker("text.txt");List<Word> words = new List<Word>();int index = -1;List<Error> errors = new List<Error>();static void Main(string[] args) {SyntaxAnalysis syntax = new SyntaxAnalysis();syntax.grammerParser();Console.ReadKey();}/// <summary>/// 语法分析/// </summary>public void grammerParser() {do {functionParser();} while(nextWord().typeNum != WordPicker.endTypeNumber);if(success)Console.WriteLine("成功");}private void functionParser() {Word word = nextWord();//返回类型if(!KeyWords.isReturnType(word)) {addError(word, "返回值错误");}word = nextWord();//函数名if(!isIdentifier(word)) {addError(word, "函数名错误");}//（参数）{word = nextWord();if(!isLeftBracket(word)) {addError(word, "(缺失");}arguments();word = nextWord();if(!isRightBracket(word)) {addError(word, ")缺失");}word = nextWord();if(word.typeNum != Symbols.left_curly_bracket.typeNum) {addError(word, "{缺失");}//语句串statementSequence();//}word = nextWord();if(word.typeNum != Symbols.right_curly_bracket.typeNum) {addError(word, "}缺失");retractWord();}}private bool isLeftBracket(Word word) {return word.typeNum == Symbols.left_bracket.typeNum;}private bool isRightBracket(Word word) {return word.typeNum == Symbols.right_bracket.typeNum;}bool success = true;private void addBeforeError(Word word, string v) {success = false;Console.WriteLine(word.ToPositionInfo() + "\t之前 " + v);}private void addError(Word word, string v) {success = false;Console.WriteLine(word.ToPositionInfo() + "\t" + v);}/// <summary>/// 参数/// </summary>private void arguments() {Word word = nextWord();if(!KeyWords.isType(word)) {if(isIdentifier(word))addBeforeError(word, "参数类型缺失");else {if(lastWord().typeNum == Symbols.comma.typeNum)addBeforeError(word, ",多余");retractWord();return;}}word = nextWord();if(!isIdentifier(word)) {addBeforeError(word, "参数标识符错误");if(isRightBracket(word)) {retractWord();return;}}//逗号word = nextWord();if(word.typeNum == Symbols.comma.typeNum) {arguments();}else if(isRightBracket(word)) {retractWord();return;}}private bool isIdentifier(Word word) {return word.typeNum == WordPicker.identifierTypeNumber;}/// <summary>/// 语串/// </summary>private void statementSequence() {Word word = nextWord();while(word.typeNum != Symbols.right_curly_bracket.typeNum && word.typeNum != WordPicker.endTypeNumber) {if(KeyWords.isType(word)) {defineStatement();}else if(isIdentifier(word)) {assignStatement();}else {addError(word, "多余");}/*  else if(KeyWords.isCondition(word)) {}else if(KeyWords.isFORLoop(word)) {}else {// addError(word, "多余");}*/word = nextWord();}retractWord();}/// <summary>/// 定义语句/// </summary>private void defineStatement() {Word word = nextWord();if(!isIdentifier(word)) {addBeforeError(word, "变量名缺失");retractWord();}word = nextWord();if(word.typeNum == Symbols.assign.typeNum) {expressStatement();word = nextWord();}if(word.typeNum == Symbols.comma.typeNum) {defineStatement();}else if(word.typeNum != Symbols.semicolon.typeNum) {addBeforeError(word, ";缺失");retractWord();}}/// <summary>/// 赋值语句/// </summary>private void assignStatement() {Word word = nextWord();if(word.typeNum != Symbols.assign.typeNum) {addBeforeError(word, "=缺失");retractWord();}expressStatement();word = nextWord();if(word.typeNum != Symbols.semicolon.typeNum) {addBeforeError(word, ";缺失");retractWord();}}/// <summary>/// 表达式/// </summary>private void expressStatement() {term();Word word = nextWord();while(word.typeNum == Symbols.add.typeNum || word.typeNum == Symbols.sub.typeNum) {term();word = nextWord();}         retractWord();}private void term() {factor();Word word = nextWord();while(word.typeNum == Symbols.mul.typeNum || word.typeNum == Symbols.except.typeNum || word.typeNum == Symbols.remain.typeNum) {factor();word = nextWord();}retractWord();}/// <summary>/// 表达式因子/// </summary>private void factor() {Word word = nextWord();if(isValue(word))return;if(word.typeNum == Symbols.left_bracket.typeNum) {expressStatement();word = nextWord();if(word.typeNum != Symbols.right_bracket.typeNum) {addBeforeError(word, ")缺失");retractWord();}}else {addBeforeError(word, "表达式错误");retractWord();}}/// <summary>/// 判断是否是数值类型/// </summary>/// <param name="word"></param>/// <returns></returns>private bool isValue(Word word) {return word.typeNum == WordPicker.numberTypeNumber|| word.typeNum == WordPicker.charTypeNumber|| word.typeNum == WordPicker.stringTypeNumber|| word.typeNum == WordPicker.identifierTypeNumber;}/// <summary>/// 读取下一个词/// </summary>/// <returns></returns>private Word nextWord() {index++;if(words.Count <= index) {Word w = wordPicker.Scanner();if(words.Count == 0 || words[words.Count - 1].typeNum != WordPicker.endTypeNumber)words.Add(w);index = words.Count - 1;}return words[index];}/// <summary>/// 现在的词/// </summary>/// <returns></returns>private Word nowWord() {if(words.Count > index && index >= 0) {return words[index];}return null;}/// <summary>/// 上一个词/// </summary>/// <returns></returns>private Word lastWord() {if(index > 0) {return words[index - 1];}else {return null;}}/// <summary>/// 回退一个词/// </summary>private void retractWord() {if(index >= 0) {index--;}}}
}

 

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;namespace SyntaxAnalysis {/// <summary>/// 词/// </summary>class Word {public int typeNum;public string word;public int col=0;public int row=0;public override string ToString() {return "(" + typeNum + "," + word + ")";}public string ToPositionInfo() {return "行:"+(row+1)+"\t列:"+col+"\t码:"+typeNum + "\t字:" + word;}}class WordPicker {string[] input;//int input_index = 0;int row = 0;int col = 0;char character;/// <summary>/// 操作符表/// </summary>    string[] operatorSort = null;public static int identifierTypeNumber;    //变量名类型public static int numberTypeNumber;        //数值类型public static int charTypeNumber;          //字符类型public static int stringTypeNumber;        //字符串类型public static int endTypeNumber = -1;      //结束符类型public static int errorTypeNumber = -2;    //出错类型public static int noDefine = -3;           //未定义类型public static char nullChar = '\0';public WordPicker(string file) {input= File.ReadAllLines(file);           identifierTypeNumber = KeyWords.keyWordTable.Length+1;numberTypeNumber = KeyWords.keyWordTable.Length + 2;charTypeNumber = KeyWords.keyWordTable.Length + 3;stringTypeNumber = KeyWords.keyWordTable.Length + 4;operatorSort = new string[Symbols.operatorTable.Length];Array.Copy(Symbols.operatorTable, operatorSort, Symbols.operatorTable.Length);Array.Sort(operatorSort);Array.Reverse(operatorSort);}/// <summary>/// 读词/// </summary>/// <returns></returns>public Word Scanner() {Word myWord;          read();readValidChar();//标识符if(char.IsLetter(character)) {myWord=readWord();}//数值else if(char.IsDigit(character)) {myWord = readDigit();}//字符常量else if(character == '\'') {myWord = readConstChar();}//字符串else if(character == '\"') {myWord = readConstString();}/*//结束符else if(character == endChar) {myWord.word = "" + endChar;myWord.typeNum = endTypeNumber;}*///空值else if(character == nullChar) {myWord = new Word();myWord.row = row;myWord.col = col;myWord.word = "Ending";myWord.typeNum = endTypeNumber;}//其他字符else {myWord = readOtherChar();}return myWord;}/// <summary>/// 标识符/// </summary>/// <param name="myWord"></param>private Word readWord() {Word myWord = new Word();myWord.row = row;myWord.col = col;while(char.IsLetter(character) || char.IsDigit(character)) {myWord.word += character;read();}retract();myWord.typeNum = KeyWords.getTypeNumber(myWord.word);return myWord;}/// <summary>/// 其他字符/// </summary>/// <param name="myWord"></param>private Word readOtherChar() {Word myWord = new Word();myWord.row = row;myWord.col = col;string s = "" + character;for(int i = 0; i < 2; i++) {read();if(character == nullChar) {break;}s += character;}foreach(string op in operatorSort) {if(s.StartsWith(op)) {retract(s.Length - op.Length);s = op;break;}}myWord.word = s;myWord.typeNum = Symbols.getTypeNumber(myWord.word);return myWord;}private void retract(int v) {if(v == 0)return;col=col-v-1;if(col < 0) {row--;col = input[row].Length + col;}read();}/// <summary>/// 识别数字常量/// </summary>/// <param name="myWord"></param>private Word readDigit() {Word myWord = new Word();myWord.row = row;myWord.col = col;while(char.IsDigit(character)) {myWord.word += character;read();}if(character == '.') {myWord.word += character;read();while(char.IsDigit(character)) {myWord.word += character;read();}}retract();myWord.typeNum = numberTypeNumber;return myWord;}/// <summary>/// 识别字符常量/// </summary>/// <param name="myWord"></param>private Word readConstChar() {Word myWord = new Word();myWord.row = row;myWord.col = col;// myWord.word = "" + character;read();//读取直到'\''结束while(character != '\'') {myWord.word += character;read();//读到空字符或结束字符if(character == nullChar /*|| character == endChar*/|| char.IsControl(character)) {/* if(character == endChar) {myWord.word +=endChar;} */myWord.typeNum = errorTypeNumber;return myWord;}}// myWord.word += character;Match r = Regex.Match(myWord.word, "^(\\\\([0-7]{1,3}|x[0-9a-fA-F]+|[abfnrtv\\\\\'\"?])|[^\\\\])$");//转义字符模式匹配if(!r.Success) {myWord.typeNum = errorTypeNumber;return myWord;}myWord.typeNum = charTypeNumber;return myWord;}/// <summary>/// 识别常量字符串/// </summary>/// <param name="myWord"></param>private Word readConstString() {Word myWord = new Word();myWord.row = row;myWord.col = col;// myWord.word = "" + character;read();while(character != '\"') {myWord.word += character;read();//读到空字符或结束字符if(character == nullChar || char.IsControl(character)) {// myWord.word += "0";myWord.typeNum = errorTypeNumber;return myWord;}}// myWord.word += character;//转义字符模式匹配if(!isLegalString(myWord.word)) {myWord.typeNum = errorTypeNumber;return myWord;}myWord.typeNum = stringTypeNumber;return myWord;}/// <summary>/// 合法字符串书写/// </summary>/// <param name="word"></param>/// <returns></returns>private bool isLegalString(string word) {int i = 0;while(i < word.Length) {if(word[i] == '\\') {if(++i == word.Length)return false;foreach(char c in translateChar) {if(c == word[i]) {goto aLabel;}}return false;}aLabel:i++;}return true;}const string translateChar = "abfnrtv\\\'\"?";const string realChar = "\a\b\f\n\r\t\v\\\'\"?";/// <summary>/// 转换为真实字符串/// </summary>/// <param name="word"></param>/// <returns></returns>private string toRealString(string word) {string res = "";int index;for(int i = 0; i < word.Length; i++) {if(word[i] == '\\') {if(++i == word.Length)throw new Exception("字符串以\\结尾异常");index = translateChar.IndexOf(word[i]);if(index == -1)throw new Exception("\\" + word[i] + "解析异常");res += realChar[index];}else {res += word[i];}}return res;}/// <summary>/// 读一个字符/// </summary>void read() {if(input.Length <= row|| input.Length == row+1 && input[input.Length-1].Length<=col) {character = '\0';}else {if(col >= input[row].Length) {col = 0;row++;}character = input[row][col];col++;}}/// <summary>/// 去除无效字符/// </summary>void readValidChar() {while(char.IsWhiteSpace(character)) {if(character == '\0') {return;}read();              }//判断注释if(character == '/' && input[row].Length > col) {ignoreNote();}}private void ignoreNote() {read();//注释‘//’if(character == '/') {row++;col = 0;                              read();readValidChar();}//注释‘/*。。。*/’else if(character == '*') {read();if(character == '\0') {return;}char c;while(true) {c = character;read();if('*' == c && '/' == character) {read();readValidChar();return;}if(character == '\0') {return;}                }}else {retract();}}void retract() {            col=col-2;if(col < 0) {row--;col = input[row].Length + col;}read();}}
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;namespace SyntaxAnalysis {class KeyWords {/// <summary>/// 关键字表/// </summary>public static string[] keyWordTable = {"auto","break","case", "char","const","continue","default","do","double","else","enum","extern","float","for","goto","if", "int","long", "register","return","short","signed","sizeof","static","struct","switch","typedef","union","unsigned","void","volatile","while"};public static Word AUTO, BREAK, CASE, CHAR, CONST,CONTINUE, DEFAULT, DO, DOUBLE,ELSE, ENUM, EXTERN, FLOAT, FOR,GOTO, IF, INT, LONG, REGISTER,RETURN, SHORT, SIGNED, SIZEOF, STATIC,STRUCT, SWITCH, TYPEDEF, UNION, UNSIGNED,VOID, VOLATILE, WHILE;static KeyWords() {Type t = typeof(KeyWords);FieldInfo[] fields = t.GetFields();Word word;foreach(FieldInfo f in fields)if(f.FieldType.Equals(typeof(Word))) {word = new Word();word.word = f.Name.ToLower();word.typeNum = getTypeNumber(word.word);f.SetValue(t, word);}}/// <summary>/// 获取关键字编码/// </summary>/// <returns></returns>public static int getTypeNumber(string s) {for(int i = 0; i < keyWordTable.Length; i++) {if(keyWordTable[i] == s) {return i+1;}}return WordPicker.identifierTypeNumber;}public static bool isPrefType(Word w) {return SIGNED.typeNum == w.typeNum|| UNSIGNED.typeNum == w.typeNum;}public static bool isType(Word w) {return INT.typeNum == w.typeNum|| CHAR.typeNum == w.typeNum|| DOUBLE.typeNum == w.typeNum|| FLOAT.typeNum == w.typeNum|| SHORT.typeNum == w.typeNum;               }public static bool isReturnType(Word w) {return isType(w) || VOID.typeNum == w.typeNum;}internal static bool isCondition(Word word) {return word.typeNum == IF.typeNum;}internal static bool isFORLoop(Word word) {return word.typeNum == FOR.typeNum|| word.typeNum == WHILE.typeNum;}internal static bool isWhileLoop(Word word) {return word.typeNum == WHILE.typeNum;}internal static bool isDoLoop(Word word) {return  word.typeNum == DO.typeNum;}internal static bool isKeyWord(Word word) {return word.typeNum > 0 && word.typeNum <= keyWordTable.Length;}}class Symbols {public static string[] operatorTable = {"{","}","[","]","(",")","->",".","++","--","!","&&","||","~","&","|","^","+","-","*","/","%","<<",">>","<",">",">=","<=","==","!=","?",":",",",";","=","+=","-=","*=","/=","%=","&=","^=","|=","<<=",">>="};public static Word left_curly_bracket, right_curly_bracket,left_square_bracket, right_square_bracket,left_bracket, right_bracket,arrow, point, two_add, two_sub,logic_not, logic_and, logic_or,bitwise_not, bitwise_and, bitwise_or, bitwise_xor,add, sub, mul, except, remain,left_move, right_move,less, greater, greater_equal, less_equal,equal, not_equal, question_mark, colon, comma, semicolon,assign, add_assign, sub_assign, mul_assign, except_assign, remain_assign,and_assign, xor_assign, or_assign, left_move_assign, right_move_assign;internal static bool isSemicolo(Word word) {return word .typeNum == semicolon.typeNum;}static Symbols() {Type t = typeof(Symbols);FieldInfo[] fields = t.GetFields();Word word;int index = 0;foreach(FieldInfo f in fields)if(f.FieldType.Equals(typeof(Word))) {word = new Word();word.word = operatorTable[index++];word.typeNum = getTypeNumber(word.word);f.SetValue(t, word);}}public static int getTypeNumber(string s) {int start = 100;for(int i = 0; i < operatorTable.Length; i++) {if(operatorTable[i] == s) {return start + i;}}return WordPicker.noDefine;}}
}

输入text.txt：

void main(int a,int b){	//int a=4-2;int a=a,b=a*82,c= a;b=12-12*x//long b=a-a8 b-2-2;//int bc=b-c*88/9;
}

输出：