📄 词法分析器.txt
字号:
// cifa0.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include"iostream"
#include"windows.h"
#define MAX 255
FILE *infile ,*outfile;
char strToken[MAX];//存放构成单词符号的字符串；
char ch;//存放最新读进的源程序字符；
int pos = 0;//strToken数组的指针；
char getChar()//将下一输入字符读入ch，搜索指示器自动迁移一字符；
{
ch = fgetc(infile);
if(ch == EOF)
{
fprintf(outfile,"------End------");
}
//++pos;
return (ch);
}
char GetBC()//检查ch中的字符是否为空白，若是，调用GetChar()，直至读入非空字符；
{
while(ch == ' '||ch =='\n'||ch =='\t'||ch =='\b')
{
getChar();
}
return (ch);
}
void Concat(char ch)//将ch中的字符连接到strToken之后；
{
strToken[pos++] = ch;
}
bool IsLetter(char ch)
{
if((ch >='a'&& ch <='z')||(ch >='A'&&ch <='Z'))
return true;
else return false;
}
bool IsDigit(char ch)
{
if(ch >='0'&&ch <='9')
return true;
else return false;
}
void Retract()//处理*
{
--pos;
ch = ' ';
}
int keyList(char strToken[])
{ //标识符和32个关键字
if(strcmp(strToken,"auto")==0)
return 1;
else if(strcmp(strToken,"double")==0)
return 2;
else if(strcmp(strToken,"int")==0)
return 3;
else if(strcmp(strToken,"struct")==0)
return 4;
else if(strcmp(strToken,"break")==0)
return 5;
else if(strcmp(strToken,"else")==0)
return 6;
else if(strcmp(strToken,"long")==0)
return 7;
else if(strcmp(strToken,"switch")==0)
return 8;
else if(strcmp(strToken,"case")==0)
return 9;
else if(strcmp(strToken,"enum")==0)
return 10;
else if(strcmp(strToken,"register")==0)
return 11;
else if(strcmp(strToken,"typedef")==0)
return 12;
else if(strcmp(strToken,"char")==0)
return 13;
else if(strcmp(strToken,"extern")==0)
return 14;
else if(strcmp(strToken,"return")==0)
return 15;
else if(strcmp(strToken,"const")==0)
return 17;
else if(strcmp(strToken,"flaot")==0)
return 18;
else if(strcmp(strToken,"short")==0)
return 19;
else if(strcmp(strToken,"unsigned")==0)
return 20;
else if(strcmp(strToken,"continue")==0)
return 21;
else if(strcmp(strToken,"for")==0)
return 22;
else if(strcmp(strToken,"signed")==0)
return 23;
else if(strcmp(strToken,"void")==0)
return 24;
else if(strcmp(strToken,"default")==0)
return 25;
else if(strcmp(strToken,"goto")==0)
return 26;
else if(strcmp(strToken,"do")==0)
return 29;
else if(strcmp(strToken,"if")==0)
return 30;
else if(strcmp(strToken,"static")==0)
return 31;
else if(strcmp(strToken,"while")==0)
return 32;
else //标识符
return 33;
}
int keyList2(char strToken[])
{//运算符
if(strcmp(strToken,"+")==0)
return 34;
if(strcmp(strToken,"++")==0)
return 35;
if(strcmp(strToken,"+=")==0)
return 36;
else if(strcmp(strToken,"-")==0)
return 37;
if(strcmp(strToken,"--")==0)
return 38;
if(strcmp(strToken,"-=")==0)
return 39;
else if(strcmp(strToken,"*")==0)
return 40;
else if(strcmp(strToken,"**")==0)
return 41;
else if(strcmp(strToken,"*=")==0)
return 42;
else if(strcmp(strToken,"/")==0)
return 43;
else if(strcmp(strToken,"/=")==0)
return 44;
else if(strcmp(strToken,"=")==0)
return 45;
else if(strcmp(strToken,"==")==0)
return 46;
else if(strcmp(strToken,"!")==0)
return 47;
else if(strcmp(strToken,"!=")==0)
return 48;
else if(strcmp(strToken,"{")==0)
return 49;
else if(strcmp(strToken,"}")==0)
return 50;
else if(strcmp(strToken,"(")==0)
return 51;
else if(strcmp(strToken,")")==0)
return 52;
else if(strcmp(strToken,"[")==0)
return 53;
else if(strcmp(strToken,"]")==0)
return 54;
else if(strcmp(strToken,">")==0)
return 55;
else if(strcmp(strToken,">=")==0)
return 56;
else if(strcmp(strToken,"<")==0)
return 57;
else if(strcmp(strToken,"<=")==0)
return 58;
else if(strcmp(strToken,"&")==0)
return 59;
else if(strcmp(strToken,"%")==0)
return 60;
else if(strcmp(strToken,"#")==0)
return 61;
else if(strcmp(strToken,",")==0)
return 62;
else if(strcmp(strToken,";")==0)
return 63;
else if(strcmp(strToken,":")==0)
return 64;
else if(strcmp(strToken,"::")==0)
return 65;
else if(strcmp(strToken,"\"")==0) //" " "
return 66;
else if(strcmp(strToken,".")==0)
return 67;
else if(strcmp(strToken,"->")==0)
return 68;
else if(strcmp(strToken,"~")==0)
return 69;
else if(strcmp(strToken,">>")==0)
return 70;
else if(strcmp(strToken,"<<")==0)
return 71;
else if(strcmp(strToken,"^")==0)
return 72;
else if(strcmp(strToken,"|")==0)
return 73;
else if(strcmp(strToken,"||")==0)
return 74;
else
return 84;
}
int main(int argc, char* argv[])
{
printf("Initializing System...\n");
Sleep(500);
printf("Analying The Souce Code...\n ");
for(int i =0;i<3;i++)
{
printf("--");
Sleep(1000);
}
printf("\n");
printf("Analy Completed.The Result is in .\\outfile.txt\n");
if((infile=fopen("infile.txt","r"))==NULL)//以读方式打开输入文件;
{
printf("Open infile error!\n");
exit(0);
}
if((outfile=fopen("outfile.txt","w"))==NULL)//以写方式打开输出文件;
{
printf("open outfile error!\n");
exit(1);
}
getChar();
GetBC();
while(ch !=EOF)
{
//------------------------识别常数---------------------------------------
if(IsDigit(ch))
{ pos = 0;
while(IsDigit(ch))
{
Concat(ch);
getChar();
}
if(ch =='.')
{
Concat(ch);
getChar();
}
while(IsDigit(ch))
{
Concat(ch);
getChar();
}
if(ch=='E'|| ch=='D')
{
Concat(ch);
getChar();
if(ch =='+'||ch =='-')
{
Concat(ch);
getChar();
if(IsDigit(ch))
{
Concat(ch);
getChar();
}
}
if(IsDigit(ch))
{
Concat(ch);
getChar();
}
while(IsDigit(ch))
{
Concat(ch);
getChar();
}
strToken[pos++] ='\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",0,'"',strToken,'"',")");
}
else
{
strToken[pos++] ='\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",0,'"',strToken,'"',")");
}
GetBC();
}
//-----------------------------end----------------------------------------
//------------------------识别标识符和关键字---------------------------------------
if(IsLetter(ch)||ch=='_')
{ pos = 0;
while(IsLetter(ch)||IsDigit(ch)||ch=='_')
{
Concat(ch);
getChar();
}
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList(strToken),'"',strToken,'"',")");
GetBC();
}
//----------------------------------end-------------------------------------------
//----------------------------运算符 ------------------------------------
if(ch=='+')//+,++,+=
{
pos=0;
Concat(ch);
getChar();
if(ch=='+')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='-')//-,--,-=,->
{
pos=0;
Concat(ch);
getChar();
if(ch=='-')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='>')//->
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='*')//*,**,*=
{
pos=0;
Concat(ch);
getChar();
if(ch=='*')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='=')//=,==
{
pos=0;
Concat(ch);
getChar();
if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='!')//!,!=
{
pos=0;
Concat(ch);
getChar();
if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='{')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='}')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='(')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch==')')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='[')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch==']')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='>')//>,>=,>>
{
pos=0;
Concat(ch);
getChar();
if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='>')//>>
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='&')//<,<=,<<
{
pos=0;
Concat(ch);
getChar();
if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='&')//<<
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='%')//!,!=
{
pos=0;
Concat(ch);
getChar();
if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='#')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch==',')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch==';')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch==':')//:,::
{
pos=0;
Concat(ch);
getChar();
if(ch==':')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='"')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='.')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='~')
{ pos=0;
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
GetBC();
if(ch=='|')//!,!=
{
pos=0;
Concat(ch);
getChar();
if(ch=='|')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else if(ch=='=')//<<
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
}
}
GetBC();
if(ch=='?')//?=
{
pos=0;
Concat(ch);
getChar();
if(ch=='=')
{
Concat(ch);
strToken[pos++] = '\0';
fprintf(outfile,"%s%d,%c%s%c%s\n","(",keyList2(strToken),'"',strToken,'"',")");
getChar();
}
else
{
strToken[pos++] = '\0';
fprintf(outfile,"%s,%c%c\n","ERROR",":",ch);
}
}
GetBC();
//-----------------------------------end-----------------------------------------
}
fclose(infile);
fclose(outfile);
return 0;
}
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -