""" 01 if 22 + 42 id eg. aCar 02 else 23 - 43 数值-整型 eg. 123 03 while 24 * 44 数值-浮点 eg. 12.3 04 do 25 / 45 数值-二进制 eg. 0b123 05 main 26 = 46 数值-八进制 eg. 0o123 06 int 27 < 47 数值-16进制 eg. 0x1BF 07 float 28 { 48 字符串常量 eg. "hjy hjy" 08 double 29 } 09 return 30 ; 10 const 31 ( 11 void 32 ) 12 continue 33 ' 13 break 34 " 14 char 35 == 15 unsigned 36 != 16 enum 37 && 17 long 38 || 18 switch 39 > 19 case 40 >= 20 auto 41 <= 21 static """ program = "" program_new = [] filename = "" keyword = ["if", "else", "while", "do", "main", "int", "float", "double", "return", "const", "void", "continue", "break", "char", "unsigned", "enum", "long", "switch", "case", "auto", "static"] # 清除注释 def Read(): global program, filename filename = input("请输入文件名") f1 = open(filename + ".txt") read_current_state = 0 # 保存当前状态 for read_line in f1: for read_char in read_line: if read_current_state == 0: if read_char == '/': read_current_state = 1 continue else: program += read_char continue if read_current_state == 1: if read_char == '*': read_current_state = 2 continue elif read_char == '/': read_current_state = 4 continue else: read_current_state = 0 continue if read_current_state == 2: if read_char == '*': read_current_state = 3 continue else: read_current_state = 2 continue if read_current_state == 3: if read_char == '/': read_current_state = 0 continue elif read_char == '*': read_current_state = 3 continue else: read_current_state = 2 continue if read_current_state == 4: if read_char == '\n': read_current_state = 0 program += read_char continue else: read_current_state = 4 continue f1.close() # 消除主程序前的空行 while program[0] == '\n': program = program[1:] # 消除主程序中的空行与段前空格 index_of_blank = 1 while index_of_blank < len(program): if program[index_of_blank - 1] == '\n' and (program[index_of_blank] == ' ' or program[index_of_blank] == '\n'): program = program[:index_of_blank] + program[index_of_blank + 1:] else: index_of_blank += 1 # 按格式输出修改后的主程序 row = 1 print(row, '\t', end='') for i in program: print(i, end='') if i == '\n': row += 1 print(row, '\t', end='') print('\n') def GetToken(): global program, program_new, program_char, is_string, token, symbol, line, line_word if is_string == 0 and program[program_char - 1] == '\"': is_string = 1 symbol = 48 while True: token += program[program_char] program_char += 1 if program[program_char] == '\"': return if is_string == 1 and program[program_char - 1] == '\"': is_string = 0 while program[program_char] == ' ' or program[program_char] == '\t': program_char += 1 line_word += 1 if program[program_char] == '\n': line += 1 line_word = 1 program_char += 1 if 'a' <= program[program_char] <= 'z' or 'A' <= program[program_char] <= 'Z' or program[program_char] == '_': symbol = 42 # id while True: token += program[program_char] program_char += 1 if not ('a' <= program[program_char] <= 'z' or 'A' <= program[program_char] <= 'Z' or '0' <= program[program_char] <= '9' or program[program_char] == '_'): break if token in keyword: symbol = keyword.index(token) + 1 return return # 42 id eg.aCar # 43 数值 - 整型 eg.123 # 44 数值 - 浮点 eg.12.3 # 45 数值 - 二进制 eg.0b010 # 46 数值 - 八进制 eg.0o123 # 47 数值 - 16进制 eg.0x1BF # 48 字符串常量 eg."hjy hjy" if program[program_char] == '0': token += program[program_char] program_char += 1 if program[program_char].lower() == 'b': while True: token += program[program_char] program_char += 1 if not ('0' <= program[program_char] <= '1'): break symbol = 45 # 数值 - 二进制 elif program[program_char].lower() == 'o': while True: token += program[program_char] program_char += 1 if not ('0' <= program[program_char] <= '7'): break symbol = 46 # 数值 - 八进制 elif program[program_char].lower() == 'h': while True: token += program[program_char] program_char += 1 if not ('0' <= program[program_char] <= '9' or 'a' <= program[program_char].lower() <= 'f'): break symbol = 47 # 数值 - 十六进制 elif program[program_char] == '.': while True: token += program[program_char] program_char += 1 if not ('0' <= program[program_char] <= '9'): break symbol = 44 # 数值 - 浮点数[1-9].xxx else: symbol = 43 # 数值 - 数字0 elif '1' <= program[program_char] <= '9': while True: token += program[program_char] program_char += 1 if program[program_char] == '.': symbol = 44 # 数值 - 浮点数[1-9]*.xxx while True: token += program[program_char] program_char += 1 if not ('0' <= program[program_char] <= '9'): symbol = 44 # 数值 - 浮点数[1-9]*.xxx return if not ('0' <= program[program_char] <= '9') and symbol != 44: symbol = 43 # 数值 - 整型 return else: if program[program_char] == '+': symbol = 22 token = '+' elif program[program_char] == '-': symbol = 23 token = '-' elif program[program_char] == '*': symbol = '*' token = program[program_char] elif program[program_char] == '/': symbol = '/' token = program[program_char] elif program[program_char] == '=': symbol = 26 token = '=' program_char += 1 if program[program_char] == '=': token = '==' symbol = 35 elif program[program_char] == '<': symbol = 27 token = '<' program_char += 1 if program[program_char] == '=': token = '<=' symbol = 41 elif program[program_char] == '>': symbol = 39 token = '>' program_char += 1 if program[program_char] == '=': token = '>=' symbol = 40 elif program[program_char] == '{': symbol = 28 token = '{' elif program[program_char] == '}': symbol = 29 token = '}' elif program[program_char] == ';': symbol = 30 token = ';' elif program[program_char] == '(': symbol = 31 token = '(' elif program[program_char] == ')': symbol = 32 token = ')' elif program[program_char] == '\'': symbol = 33 token = '\'' elif program[program_char] == '\"': symbol = 34 token = '\"' elif program[program_char] == '!': program_char += 1 if program[program_char] == '=': token = '!=' symbol = 36 elif program[program_char] == '&': program_char += 1 if program[program_char] == '&': token = '&&' symbol = 37 elif program[program_char] == '|': program_char += 1 if program[program_char] == '|': token = '||' symbol = 37 else: symbol = -2 program_char += 1 return if __name__ == "__main__": print("-----------Step 1 消除注释--------------") Read() print("-----------Step 2 词法分析--------------") line = 1 line_word = 1 is_string = 0 program_char = 0 while program_char < len(program): token = "" symbol = 0 GetToken() if len(program_new) > 1: if program_new[-1][0] in [6, 7, 8, 11, 14, 15, 16, 17]: if symbol == 43: print("变量名不能以数字开头") symbol = -1 elif symbol not in [5, 42]: print("缺少变量名") symbol = -2 elif program_new[-1][0] in [43, 44, 45, 46, 47]: if symbol in [42, 43, 44, 45, 46, 47]: print("数字书写不规范") symbol = -3 if len(program_new) > 2: if program_new[-3][0] == 6: if symbol not in [32, 43, 45, 46, 47]: print("变量不是int类型") symbol = -4 elif program_new[-3][0] in [7, 8]: if symbol != 44: print("变量不是float类型") symbol = -5 if len(program_new) > 3: if program_new[-4][0] == 14: if symbol != 48: print("变量不是char类型") symbol = -6 print(f'({symbol:>2},{token:^8})\tline:{line},row:{line_word}') program_new.append([symbol, token, line, line_word]) line_word += len(token) program_new_words = [i[1] for i in program_new] # 判断引号括号等是否匹配 if program_new_words.count('\'') % 2 == 1: print("单引号数量不匹配") if program_new_words.count('\"') % 2 == 1: print("双引号数量不匹配") if program_new_words.count('(') != program_new_words.count(')'): print("小括号数量不匹配") if program_new_words.count('{') != program_new_words.count('}'): print("大括号数量不匹配") # 存入文件 f2 = open(filename + "-out.txt", 'w') for i in program_new: for j in i: f2.write(str(j) + ',') f2.write('\n') f2.close() print("词法分析结束，存入文件" + filename + "-out.txt")