修改了一些不兼容的问题，删除了输出语法树部分内容，简易版，需要的可自取。
#include<bits/stdc++.h> #define xcx(x) printf("ojbk %d\n",(x)) using namespace std; const int KEY_WORD_NUM = 13 ; const int OPERATOR_WORD_NUM = 19; const int DELIMITER_WORD_NUM = 6 ; const int row_limit = 130; //词法分析常量 const string _data_type = "data type" ; const string _statement_keyword = "statement keyword" ; const string _identifier = "identifier" ; const string _single_arithmetic_operator = "single arithmetic operator" ; const string _compare_operator = "compare operator" ; const string _double_arithmetic_operator = "double arithmetic operator" ; const string _delimiter = "delimiter" ; const string _unsigned_number = "unsigned number" ; const string _const_string = "const string" ; const string _const_character = "const character"; const string ANNOTATIONL1 = "//" ; const string ANNOTATIONL2 = "/*" ; const string key_word [ KEY_WORD_NUM ] = { "break", "if", "else", "for", "while", "do", "int", "double", "char", "read", "write", "bool", "string" } ; const string operator_word [ OPERATOR_WORD_NUM ]= { "+=", "-=", "*=", "\=", "+", "-", "*", "/", "=", "++", "--", "<", ">", "<=", ">=", "!=", "==", "//", "/*" } ; const string delimiter_word [ DELIMITER_WORD_NUM ] = { "(", ")", "{", "}", ",", ";"}; //语法分析常量 const string _program = "program" ; const string _declaration = "declaration" ; const string _expression = "expression" ; const string _expression_bool = "expression bool" ; const string _expression_cal = "expression cal" ; const string _term = "term" ; const string _factor = "factor" ; const string _statement = "statement" ; const string _statement_if = "if - statement"; const string _statement_while = "while - statement" ; const string _statement_do_while = "do-while - statement"; const string _statement_for = "for - statement" ; const string _statement_write = "write - statement" ; const string _statement_read = "read - statement" ; const string _statement_compound = "compound statement" ; const string _statement_expression = "expression statement" ; const string _constant = "constant" ; const string _number = "number" ; struct Node_operator { string str; bool is_terminator; map < char, int > next; Node_operator(){ str.clear(); is_terminator = false; next.clear(); } Node_operator( const string &str ){ this -> next.clear(); this -> str = str; this -> is_terminator = false; } }; struct Word { string type; string val; Word(){ type.clear(); val.clear(); } Word( const string &str , const string &val ){ this -> type = str; this -> val = val; } void print(){ printf( " %s <%s> \n", this -> val.c_str(), this -> type.c_str() ); } bool operator != (const Word &other) const { return other.type != this->type || other.val != this->val ; } bool operator == (const Word &other) const { return other.type == this->type && other.val == this->val ; } }; struct Unit { vector< Unit > u ; string val ; string type; bool is_error; Unit(){ is_error = false ; } Unit ( const string type ) { this -> is_error = false ; this -> type = type; } Unit ( const Word &w ) { this -> is_error = false ; this -> type = w.type ; this -> val = w.val ; u.clear(); } inline void print() { printf( " %s ( %s ) \n" , val.c_str() , type.c_str() ) ; } inline void println() { print(); printf("\n"); } void push( const Unit &ut ) { this -> val += ut.val; this -> u.push_back( ut ) ; } void push( const Word &w ) { this -> val += w.val; this -> u.push_back( Unit(w) ) ; } void clear() { this -> val.clear(); this -> u.clear(); } }; int now_line = 1 , error_type = 0; char ch = 0; FILE *fp ; map < string, int > key_word_id; map < char, int > operator_word_head; vector < Node_operator > state_graph; vector < Word > ans ; string error_information , fin_name , fout_name ; Word finish , error_word, wd; Unit error_unit; void read(char &c){ if( fscanf( fp , "%c" , &c ) == EOF ) c = EOF; if( c == '\n' ) now_line++ ; } ///词法分析识别函数 inline bool Is_Character ( const char &c ) { return c>='A'&&c<='Z' || c>='a'&&c<='z' || c=='_'; } inline bool Is_Number( const char &c ) { return c>='0'&&c<='9' ; } inline bool Is_Operator_head ( const char &c ) { return operator_word_head.count(c) > 0 ; } inline bool Is_Data_type ( const string &s ){ return s=="int" || s=="double" || s=="char" || s=="string" || s=="bool" ; } inline bool Is_Blank ( const char &c ) { return c == ' ' || c == '\t' || c == '\n' ; } inline bool Is_Delimiter ( const char &c ) { return c=='(' || c==')' || c=='{' || c=='}' || c==';' || c==',' ; } inline bool Is_Compare_operator ( const string &s ) { return s=="<" || s==">" || s=="<=" || s==">=" || s=="==" || s=="!=" ; } void InitTestScan(){ //读取标识符 key_word_id.clear(); for( int i=0; i<KEY_WORD_NUM; i++ ) { key_word_id[ key_word[i] ] = i; } //读取运算符头字母 operator_word_head.clear(); for( int i=0; i<OPERATOR_WORD_NUM; i++ ) { operator_word_head[ operator_word[i][0] ] = i; } //运算符建图 state_graph.clear(); state_graph.push_back( Node_operator() ); for( int i=0; i<OPERATOR_WORD_NUM; i++ ) { const string &temp = operator_word[i]; int node_index = 0; for( int j=0; j<(int)temp.length(); j++ ) { Node_operator &now_node = state_graph[node_index]; if( now_node.next.count( temp[j] ) == 0 ) { now_node.next[ temp[j] ] = state_graph.size(); state_graph.push_back( Node_operator( now_node.str +temp[j] ) ); node_index = state_graph.size() -1 ; } else{ node_index = now_node.next[ temp[j] ]; } } state_graph[node_index].is_terminator = true ; } //vector<> 清空 ans.clear(); //当前行起点为1 now_line = 1; //常量终止Word赋值 finish.type.clear(); finish.val.clear(); //error处理信息 error_type = 0 ; error_information.clear() ; error_word = Word( string("error"), string("?") ); error_unit.is_error =true; error_unit.type.clear(); error_unit.val.clear(); } void PrintError( int op ); int InputTestScan(){ printf( "input the name of the source program...\n" ); cin >> fin_name ; fp = fopen( fin_name.c_str(), "r" ); if( fp == NULL ) return 1; //else fclose( fp ); //printf( "input the name of the output file...\n" ); //cin >> fout_name ; //freopen( fin_name.c_str(), "r", stdin ) ; return 0; } void InitGetWord(){ InitTestScan(); read( ch ); } ///语法分析识别函数 Word GetWord(){ //读取一个标识 Word ret = finish ; while( ch != EOF ){ while( Is_Blank(ch) ){ read( ch ); if( ch == EOF ) return ret; } if( Is_Character(ch) == true ) { //处理标识符 string str; while( Is_Character(ch) == true || Is_Number(ch) == true ) { str += ch; read( ch ); } if( key_word_id.count(str) > 0 ) { if( Is_Data_type( str ) == true ) { ret = Word(_data_type, str); } else { ret = Word(_statement_keyword, str); } } else { ret = Word(_identifier, str) ; } } else if( Is_Number(ch) == true ) { //处理数字常量 string str; bool is_decimal = false; while( Is_Number(ch) == true ) { str +=ch; read( ch ); } if( ch == '.' ) { is_decimal = true; str +=ch; read( ch ); while( Is_Number(ch) == true ) { str +=ch; read( ch ); } if( Is_Character(ch) || ch == '.' ){ error_type = 3; while( !Is_Blank(ch) && !Is_Delimiter(ch) ) { str += ch; read( ch ); } if ( ch == '\n' ) now_line-- ; error_information = str; return error_word; } } if( is_decimal == true ) { if( str[str.size()-1] == '.' ) { error_information = str ; error_type = 4; return error_word; } } ret = Word( _unsigned_number, str ) ; } else if ( ch == '\'' ) { //处理单引号 string str; str +=ch; read( ch ); while( ch!='\'' && ch!='\n' ) { if( ch == '\\' ) { str +=ch; read( ch ); } str +=ch; read( ch ); } if( ch != '\'' ) { error_type = 5; error_information = str; return error_word; } str +=ch; ret = Word(_const_character, str) ; read( ch ); if( ret.val.length() > 3 && ret.val[1] !='\\' ) { error_type = 6; error_information = str; return error_word; } } else if ( ch == '"' ) { //处理双引号 string str; str +=ch; read( ch ); while( ch!='"' && ch!='\n' ) { if( ch == '\\' ) { str +=ch; read( ch ); } str +=ch; read( ch ); } if( ch != '"' ) { error_type = 7; error_information = str; return error_word; } str +=ch; ret = Word( _const_string, str ) ; read( ch ); } else if ( Is_Operator_head(ch) == true ) { //处理运算符 string str ; int node_index = 0; while( state_graph[node_index].next.count(ch) > 0 ) { node_index = state_graph[node_index].next[ch] ; read( ch ); while( Is_Blank(ch) == true ) read( ch ) ; } Node_operator &now_node = state_graph[node_index]; if( now_node.str == ANNOTATIONL1 ) { //处理注释1 while( ch != '\n' ) read( ch ); read( ch ); } else if( now_node.str == ANNOTATIONL2 ) { //处理注释2 char pre_ch = ch; read( ch ); while( !(pre_ch == '*' && ch == '/') ) { pre_ch = ch; read( ch ); } read( ch ); } else if( state_graph[node_index].is_terminator == false ) { //运算符不合法 error_information = state_graph[node_index].str ; error_type = 8 ; return error_word; } else { //合法运算符 str = now_node.str; if( str == "++" || str == "--" ) { ret = Word( _single_arithmetic_operator , str) ; } else if( Is_Compare_operator(str) == true ) { ret = Word( _compare_operator , str) ; } else { ret = Word( _double_arithmetic_operator , str ) ; } } } else if( Is_Delimiter(ch) == true ) { //处理分界符 string str ; str = ch; read( ch ) ; ret = Word (_delimiter , str ); } else{ //不合法字符 error_information = ch; while( Is_Blank(ch) == false ) { error_information += ch ; read( ch ); } error_type = 9; return error_word; } if( error_type != 0 || ( ret.type.length() != 0 || ret.val.length() != 0 ) ) { ret.print(); return ret; } } } Unit GetProgram() ; Unit GetDeclaration() ; Unit GetExpression() ; Unit GetExpressionBool() ; Unit GetExpressionCal() ; Unit GetTerm() ; Unit GetFactor() ; Unit GetStatement() ; Unit GetStatementIf() ; Unit GetStatementWhile() ; Unit GetStatementDoWhile() ; Unit GetStatementFor() ; Unit GetStatementWrite() ; Unit GetStatementRead() ; Unit GetStatementCompound() ; Unit GetStatementExpression() ; Unit GetConstant() ; Unit GetNumber() ; int TestScan(){ //int ret = InputTestScan(); //if( ret != 0 ) return ret; InitGetWord(); while( ch != EOF ){ ans.push_back( GetWord() ); if( error_type != 0 ) { //PrintError( error_type ); error_type = 0; error_information.clear(); } } return 0; } void OutPut(){ freopen( fout_name.c_str(), "w", stdout ); for( int i=0; i<ans.size(); i++ ) { ans[i].print(); } /*printf( "----------------------------------------------------------------\n" );*/ } int main() { fin_name = "in.txt" ; fout_name = "out.txt" ; fp = fopen( fin_name.c_str(), "r" ); //freopen( fout_name.c_str(), "w", stdout ) ; InitGetWord(); Unit ans = GetProgram(); return 0; } Unit GetProgram() { Unit ret = Unit( _program ) , add ; wd = GetWord(); if ( wd == error_word ) return error_unit; while( wd != finish ) { if( wd.type == _data_type ) { // 声明语句 add = GetDeclaration(); } else { // 语句 add = GetStatement() ; } if ( add.is_error == true ) { return error_unit ; } else { ret.push ( add ) ; } } ret.print(); return ret; } Unit GetDeclaration() { Unit ret = Unit( _declaration ) , add ; ret.push ( wd ) ; wd = GetWord(); if ( wd == error_word ) return error_unit ; if ( wd.type != _identifier ) { // <标识符> error_type = 10 ; error_information = ret.val ; return error_unit ; } else { ret.push ( wd ) ; wd = GetWord(); if ( wd == error_word ) return error_unit ; } if ( wd.val == "=" ) { // = <表达式> ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetExpression(); if( add.is_error == true ){ return error_unit ; } else { ret.push ( add ) ; } } while( wd.val == "," ) { // 循环添加 , <标识符> ret.push ( wd ) ; wd = GetWord(); if ( wd == error_word ) return error_unit ; if ( wd.type != _identifier ) { error_type = 10 ; error_information = "," ; return error_unit ; } else { ret.push ( wd ) ; wd = GetWord(); if ( wd == error_word ) return error_unit ; } if( wd.val == "=" ) { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetExpression(); if( add.is_error == true ){ return error_unit; } else { ret.push ( add ) ; } } } if( wd.val != ";" ){ // 处理分号 error_type = 11 ; error_information = ret.val ; return error_unit; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } ret.print(); return ret; } Unit GetExpression() { Unit ret = Unit ( _expression ) , add ; if ( wd.type != _identifier ) { // bool表达式 add = GetExpressionBool(); if ( add.is_error == true ) { return error_unit ; } else { ret.push ( add ) ; } } else{ long fileadd = ftell( fp ) ; // 记录当前位置 char rem_ch = ch ; // 记录当前ch Word rem_wd = wd; // 记录当前wd int rem_now_line = now_line ; // 记录当前行数 //printf("rem: %c",ch); wd.print(); ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val == "=" || wd.val == "+=" || wd.val == "-=" || wd.val == "\=" || wd.val == "*=" ) { // 赋值表达式 ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetExpressionBool(); if ( add.is_error == true ){ return error_unit; } else{ ret.push ( add ) ; } } else { //bool 表达式 fseek( fp , fileadd , 0 );// 返回记录文件位置 ch = rem_ch ; wd = rem_wd; ret.clear(); now_line = rem_now_line ; //printf("back : %c",ch); wd.print(); add = GetExpressionBool(); if ( add.is_error == true ) { return error_unit ; } else { ret.push ( add ) ; } } } ret.print(); return ret; } Unit GetExpressionBool() { Unit ret = Unit ( _expression_bool ) , add ; add = GetExpressionCal() ; if ( add.is_error == true ) { return error_unit; } else { ret.push ( add ) ; } if ( wd.type == _compare_operator ){ ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetExpressionCal() ; if ( add.is_error == true ) { return error_unit; } else { ret.push ( add ) ; } } ret.print(); return ret; } Unit GetExpressionCal() { Unit ret = Unit ( _expression_cal ) , add ; add = GetTerm() ; if ( add.is_error == true ) { return error_unit; } else { ret.push ( add ) ; if ( wd.val == "+" || wd.val == "-" ) { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetTerm() ; if ( add.is_error == true ) { return error_unit; } else { ret.push ( add ) ; } } } ret.print(); return ret; } Unit GetTerm() { Unit ret = Unit( _term ) , add ; add = GetFactor() ; if ( add.is_error == true ) { return error_unit ; } else { ret.push ( add ) ; if ( wd.val == "*" || wd.val == "/" ) { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetTerm() ; if ( add.is_error == true ) { return error_unit; } else { ret.push ( add ) ; } } } ret.print(); return ret; } Unit GetFactor() { Unit ret = Unit ( _factor ) , add ; if ( wd.val == "(" ) { //表达式 ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetExpression() ; if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push( add ) ; } if ( wd.val != ")" ) { error_type = 13 ; error_information = ret.val; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } } else if ( wd.type == _identifier ) { //标识符 ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.type == _single_arithmetic_operator ) { // 自运算 ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } } else if ( wd.val == "-" || wd.type == _unsigned_number ) { //数字常量 if( wd.type == _unsigned_number ) { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.type == _unsigned_number ) { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } else { error_type = 13 ; error_information = ret.val ; ret.is_error = true ; return ret; } } } else if ( wd.type == _const_character || wd.type == _const_string ) { //字符或字符串常量 ret.push ( wd ) ; wd = GetWord(); if ( wd == error_word ) return error_unit ; } else { //不合法factor error_type = 13 ; error_information = ret.val ; ret.is_error = true ; return ret; } ret.print(); return ret; } Unit GetStatement() { Unit ret = Unit( _statement ) , add ; if ( wd.type == _statement_keyword ) { if( wd.val == "if" ) { // if-statement add = GetStatementIf() ; } else if( wd.val == "while" ) { // while-statement add = GetStatementWhile() ; } else if( wd.val == "do" ) { // do_while-statement add = GetStatementDoWhile() ; } else if( wd.val == "for" ) { // for-statement add = GetStatementFor() ; } else if( wd.val == "write" ) { // write-statement add = GetStatementWrite() ; } else if( wd.val == "read" ) { // read-statement add = GetStatementRead() ; } else { // break 语句 ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val != ";" ) { error_type = 11 ; error_information = ret.val ; return error_unit ; } else { ret.push ( wd ) ; wd = GetWord(); if ( wd == error_word ) return error_unit ; } return ret; } } else { if( wd.val == "{" ) { //复合语句 add = GetStatementCompound() ; } else { //表达式语句 add = GetStatementExpression() ; } } if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } ret.print(); return ret; } Unit GetStatementIf() { Unit ret = Unit( _statement_if ) , add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val != "(" ) { error_type = 15 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetExpression() ; if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } if ( wd.val != ")" ) { error_type = 13 ; error_information = add.val ; ret.is_error = true; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetStatement(); if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } if ( wd.val == "else" ) { //else 语句 ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetStatement() ; if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } } ret.print(); return ret; } Unit GetStatementWhile() { Unit ret = Unit( _statement_while ) , add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val != "(" ) { error_type = 13 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetExpression() ; if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } if ( wd.val != ")" ) { error_type = 15 ; error_information = add.val ; ret.is_error = true ; return ret ; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetStatement() ; if ( add.is_error == true ) { ret.is_error = true ; return ret ; } else { ret.push ( add ) ; } ret.print(); return ret; } Unit GetStatementDoWhile() { Unit ret = Unit( _statement_do_while ) , add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; add = GetStatement() ; if ( add.is_error == true ) { ret.is_error = true ; return ret ; } else { ret.push ( add ) ; } if ( wd.val != "while" ) { error_type = 18 ; error_information = ret.val ; ret.is_error = true ; return ret ; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } if( wd.val != "(" ) { // 左括号 error_type = 15; error_information = ret.val; return error_unit ; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit; } add = GetExpressionBool() ; if ( add.is_error == true ) { ret.is_error = true ; return ret ; } else { ret.push ( add ) ; } if( wd.val != ")" ) { // 右括号 error_type = 13; error_information = ret.val; return error_unit ; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit; } if ( wd.val != ";" ) { error_type = 11 ; error_information = add.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } ret.print(); return ret; } Unit GetStatementFor() { Unit ret = Unit( _statement_for ), add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val != "(" ) { error_type = 15 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetExpression() ; // 表达式一 if ( add.is_error == true ) { ret.is_error = true ; return ret ; } else { ret.push ( add ) ; } if ( wd.val != ";" ) { // 分号一 error_type = 11; error_information = add.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetExpression() ; // 表达式二 if ( add.is_error == true ) { ret.is_error = true ; return ret ; } else { ret.push ( add ) ; } if ( wd.val != ";" ) { //分号二 error_type = 11; error_information = add.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetExpression() ; // 表达式三 if ( add.is_error == true ) { ret.is_error = true ; return ret ; } else { ret.push ( add ) ; } if ( wd.val != ")" ) { // 右括号 error_type = 13 ; error_information = add.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetStatement() ; // 循环语句 if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } ret.print(); return ret ; } Unit GetStatementWrite() { Unit ret = Unit( _statement_write ) , add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val != "(" ) { error_type = 15 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } add = GetExpressionCal() ;//算术表达式 if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } if ( wd.val != ")" ) { error_type = 13 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } if ( wd.val != ";" ) { error_type = 11 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } ret.print(); return ret; } Unit GetStatementRead() { Unit ret = Unit( _statement_read ) , add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; if ( wd.val != "(" ) { error_type = 15 ; error_information = ret.val ; ret.is_error = true ; return ret ; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } if ( wd.type != _identifier ) { error_type = 17 ; error_information = wd.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } if ( wd.val != ")" ) { error_type = 13 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } if ( wd.val != ";" ) { error_type = 11 ; error_information = ret.val ; ret.is_error = true ; return ret; } else { ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; } ret.print(); return ret; } Unit GetStatementCompound() { Unit ret = Unit( _statement_compound ), add ; ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; while( wd.val != "}" ) { add = GetStatement(); if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } } ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; ret.print(); return ret ; } Unit GetStatementExpression() { Unit ret = Unit( _statement_expression ) , add ; while( wd.val != ";" ) { add = GetExpression(); if ( add.is_error == true ) { ret.is_error = true ; return ret; } else { ret.push ( add ) ; } } ret.push ( wd ) ; wd = GetWord() ; if ( wd == error_word ) return error_unit ; ret.print(); return ret; } void PrintError( int op ){ ///文件操作相关 if( op == 1 ) { //输入文件打开失败 printf( "return = %d ERROR: fail to open the source program !\n" , op ); } if( op == 2 ) { //输出文件不存在， 理论不可能发生 printf( "return = %d ERROR: fail to open the output file !\n" , op ); } ///词法分析相关 if( op == 3 ) { //数字常量不合法 printf( "return = %d ERROR: %s is not a number in line %d !\n" , op , error_information.c_str() , now_line ); } if( op == 4 ) { //小数点后缺少数字 printf( "return = %d ERROR: Missing Numbers behind the decimal point in line %d !\n" , op , now_line ); } if( op == 5 ) { //单引号不匹配 printf( "return = %d ERROR: missing terminating \' behind %s character in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 6 ) { // 字符常量超长 printf( "return = %d ERROR: Character constants %s are excessively long in line %d !\n", error_information.c_str() , now_line ); } if( op == 7 ) { //双引号不匹配 printf( "return = %d ERROR: missing terminating \" behind %s character in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 8 ) { //运算符不合法 printf( "return = %d ERROR: the operator %s is not valid in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 9 ) { //非合法字符 printf( "return = %d ERROR: %s was not legal character in line %d !\n", op , error_information.c_str() , now_line ); } ///语法分析相关 if( op == 10 ) { //缺少标识符 printf( "return = %d ERROR: miss declaration after %s in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 11 ) { //缺少分号 printf( "return = %d ERROR: miss ';' after %s in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 12 ) { //不是合法表达式 printf( "return = %d ERROR: %s is not a expression in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 13 ) { //缺少右括号 printf( "return = %d ERROR: miss ')' after %s in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 14 ) { //不是因子 printf( "return = %d ERROR: %s is not a factor in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 15 ) { //缺少左括号 printf( "return = %d ERROR: miss '(' before %s in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 16 ) { //write括号中信息不合法 printf( "return = %d ERROR: %s is not a declaration in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 17 ) { //read括号中信息不合法 printf( "return = %d ERROR: %s is not a expression in line %d !\n", op , error_information.c_str() , now_line ); } if( op == 18 ) { //缺少while printf( "return = %d ERROR: miss while after 'do' in line %d !\n", op , now_line ); } }