学步园

经过修改:

1) 命令和参数之间由任意数量的空格和Tab建隔开

2) 支持简单的//注释符

代码如下

/*<br /> CLB.cpp<br /> 2011.1.18<br /> 本程序实现了一种最简单的基于命令的语言<br /> 该语言有以下4种命令<br /> PrintString "..."<br /> PrintStringLoop "..." number<br /> NewLine<br /> WaitForKeyPress<br /> 该程序通过读取磁盘上，用该命令写成的脚本，分析该语言，输出对应的结果<br /> //是游戏脚本高级编程的第三章的第一个程序,我用c++将其重写<br /> //运行环境 vs2005 通过<br /> 运行结果:<br /> "This is a command-based language."<br /> "Therefore,this is a command-based script."<br /> "...and it's really quite boring."<br /> "this string has been repeated four times."<br /> "this string has been repeated four times."<br /> "this string has been repeated four times."<br /> "this string has been repeated four times."<br /> "Okay,press a key already and put us both out of our misery."<br /> "The new demo is cooler,I swear."<br /> 请按任意键继续. . .<br /> */<br /> #include<fstream><br /> #include<iostream><br /> #include<string><br /> #include<vector><br /> #include<cassert><br /> #include"conio.h"<br /> #include<cctype><br /> using namespace std;<br /> #define COMMAND_PRINTSTRING "PrintString"<br /> #define COMMAND_PRINTSTRINGLOOP "PrintStringLoop"<br /> #define COMMAND_NEWLINE "NewLine"<br /> #define COMMAND_WAITFORKEYPRESS "WaitForKeyPress"<br /> //在内存中存放脚本<br /> vector<string> script;<br /> /*<br /> 函数名:LoadScript<br /> 功能:读入脚本<br /> 参数:<br /> fileName:文件名<br /> */<br /> void LoadScript(string fileName);<br /> /*<br /> 函数名:UnloadScript<br /> 功能:注销脚本<br /> */<br /> void UnloadScript();<br /> /*<br /> 函数名:RunScript<br /> 功能:运行脚本<br /> */<br /> void RunScript();<br /> /*<br /> 函数名:GetCurrentScript<br /> 功能:得到当前行的脚本<br /> 参数:<br /> line:当前行号<br /> 返回值:当前行的脚本<br /> */<br /> string& GetCurrentScript(size_t line);<br /> /*<br /> 函数名:GetCommand<br /> 功能:得到当前行的脚本的命令<br /> 参数:<br /> currentScript:当前行的脚本<br /> 返回值:得到当前行的脚本的命令<br /> */<br /> string GetCommand( string& currentScript);<br /> /*<br /> 函数名:GetIntParam<br /> 功能:得到当前行的脚本的int参数<br /> 参数:<br /> currentScript:当前行的脚本<br /> 返回值:得到当前行的脚本的int参数<br /> */<br /> int GetIntParam( string& currentScript);<br /> /*<br /> 函数名:GetStringParam<br /> 功能:得到当前行的脚本的string参数<br /> 参数:<br /> currentScript:当前行的脚本<br /> 返回值:得到当前行的脚本的string参数<br /> */<br /> string GetStringParam( string& currentScript);<br /> /*<br /> 函数名:DeleteSpaces<br /> 功能:删除当前字符串最前面的任意数量的空格和Tab符号<br /> 参数:<br /> str: 任意字符串<br /> */<br /> void DeleteSpaces(string& str);<br /> int main()<br /> {<br /> /*<br /> 本地文件cbl.txt<br /> PrintString "This is a command-based language."<br /> PrintString "Therefore,this is a command-based script."<br /> NewLine<br /> PrintString "...and it's really quite boring."<br /> NewLine<br /> PrintStringLoop "this string has been repeated four times." 4<br /> NewLine<br /> PrintString "Okay,press a key already and put us both out of our misery."<br /> PrintString "The new demo is cooler,I swear."<br /> WaitForKeyPress<br /> */<br /> string textName("cbl.txt");<br /> //加载脚本<br /> LoadScript(textName);<br /> //运行脚本<br /> RunScript();<br /> //卸载脚本<br /> UnloadScript();<br /> return 0;<br /> }<br /> void DeleteSpaces(string& currentScript)<br /> {<br /> //去掉空格和/t<br /> while ( (currentScript[0]==' ') ||<br /> (currentScript[0]=='/t')<br /> )<br /> {<br /> if(currentScript[0]==' ')<br /> currentScript.erase(0,1);<br /> else<br /> currentScript.erase(0,4);<br /> }<br /> }<br /> void LoadScript(string fileName)<br /> {<br /> ifstream file;<br /> //打开文件<br /> file.open(fileName.c_str());<br /> if(!file)<br /> {<br /> cout<<"error: unable to open the file:"<br /> <<fileName<<endl;<br /> exit(-1);<br /> }<br /> //加载到内存中<br /> while(!file.eof())<br /> {<br /> string line;<br /> getline(file,line);<br /> DeleteSpaces(line);<br /> //判断简单注释符<br /> if((line[0] == '/' ) && (line[1]== '/' ))<br /> continue;<br /> script.push_back(line);<br /> }<br /> //垃圾回收<br /> file.clear();<br /> file.close();<br /> }<br /> void UnloadScript()<br /> {<br /> //清空脚本<br /> script.erase(script.begin(),script.end());<br /> assert(script.empty());<br /> }<br /> void RunScript()<br /> {<br /> //脚本行数<br /> size_t scriptSize=script.size();</p> <p> //循环运行每一条脚本<br /> for(size_t line = 0;line !=scriptSize; ++line)<br /> {<br /> //得到当前脚本<br /> string currentScript=GetCurrentScript(line);<br /> if(currentScript.size()<=3)<br /> continue;<br /> //得到当前脚本的命令<br /> string command=GetCommand(currentScript);<br /> //根据命令不同,执行方式也不同<br /> if(command==COMMAND_PRINTSTRING)<br /> {<br /> //得到string参数<br /> string param=GetStringParam(currentScript);<br /> assert(currentScript.empty());<br /> cout<<'/t'<<param<<endl;<br /> }<br /> else if(command == COMMAND_PRINTSTRINGLOOP)<br /> {<br /> //得到string参数<br /> string param=GetStringParam(currentScript);<br /> //得到int参数<br /> int loopNum=GetIntParam(currentScript);<br /> assert(currentScript.empty());<br /> for(int i=0;i<loopNum;++i)<br /> cout<<'/t'<<param<<endl;<br /> }<br /> else if(command == COMMAND_NEWLINE)<br /> {<br /> assert(currentScript.empty());<br /> cout<<endl;<br /> }<br /> else if(command == COMMAND_WAITFORKEYPRESS)<br /> {<br /> assert(currentScript.empty());<br /> //_kbhit returns a nonzero value if a key has been pressed. Otherwise, it returns 0.<br /> while(!kbhit())<br /> ;<br /> }<br /> else<br /> {<br /> printf("/tError: Invalid command./n");<br /> break;<br /> }<br /> }<br /> }<br /> string & GetCurrentScript(size_t line)<br /> {<br /> return script[line];<br /> }<br /> string GetCommand( string& currentScript)<br /> {<br /> string command;<br /> for(size_t i=0;currentScript[i]!=' ' && i!=currentScript.size();++i)<br /> command.push_back(currentScript[i]);</p> <p> currentScript.erase(0,command.size());<br /> DeleteSpaces(currentScript);</p> <p> return command;<br /> }<br /> int GetIntParam( string& currentScript)<br /> {<br /> string loopNumString;<br /> assert(isdigit(currentScript[0]));<br /> for(size_t i=0;i!=currentScript.size() && currentScript[i]!=' ' && currentScript[i]!='/t';++i)<br /> {<br /> loopNumString.push_back(currentScript[i]);<br /> }<br /> int loopNum=atoi(loopNumString.c_str());<br /> currentScript.erase(0,loopNumString.size());<br /> DeleteSpaces(currentScript);<br /> return loopNum;<br /> }<br /> string GetStringParam( string& currentScript)<br /> {<br /> int flag=0;//1表示有1个" 2表示有2个"<br /> string param;</p> <p> assert(currentScript[0]== '"');//第一个字符应该是"<br /> for(size_t i=currentScript.find('"'); i < currentScript.size();++i)<br /> {<br /> param.push_back(currentScript[i]);<br /> if(currentScript[i] == '"')<br /> flag++;<br /> if(flag == 2)<br /> break;<br /> }<br /> currentScript.erase(0,param.size());<br /> DeleteSpaces(currentScript);<br /> return param;<br /> }