www.pudn.com > hsgbiyiyuanli.rar > cifa.h
/*==========================词法分析===========================*/
void scaner()
{
while( 1 )
{
head = readline();
sort();
if ( feof(in) )
break;
}
}
void sort()
{
char c,nextc;
while (*head != '\0')
{
while( isspace( *head ) || *head == '\t' )
{
head++;
}
c = fetch();
if ( c == '@' ) // @代表没有取到缓冲区内容
break;
nextc = fetch(); // @代表没有取到缓冲区内容
if ( c =='+' || c=='-' )
{
if ( nextc == '@' ) //nextc没有取到缓冲区内容，c取的已经是最后1个
{
unfetch(1); //仅仅是指针退后，变量c中的内容不变。
symproces();
}
else //nextc 取到缓冲区内容
{
if ( isdigit( nextc ) ) //输入的将是数字
{
unfetch( 2 ); //将c 和 nextc退入缓冲区；
dataproces();
}
else
{
unfetch( 2 ); //将nextc 退后
symproces();
}
}
}
else if( isdigit( c ) )
{
if ( nextc == '@' ) //nextc没有取到缓冲区内容，c取的已经是缓冲区最后1个
{
unfetch(1);
dataproces();
}
else //nextc 取到缓冲区内容
{
unfetch(2);
dataproces();
}
}
else if ( isalpha( c ))
{
if ( nextc == '@' ) //nextc没有取到缓冲区内容，c取的已经是缓冲区最后1个
{
unfetch(1);
alfaproces();
}
else //nextc 取到缓冲区内容
{
unfetch(2);
alfaproces();
}
}
else if( c == '\'' && isalpha(nextc) )//字符常数
{
unfetch(1);
char_process();
}
else
{
if ( nextc == '@' ) //nextc没有取到缓冲区内容，c取的已经是缓冲区最后1个
{
unfetch(1);
symproces();
}
else //nextc 取到缓冲区内容
{
unfetch(2);
symproces();
}
}
}
}
char *readline() //从文件中读取一行
{
char c =(char) fgetc(in);
unsigned int i = 0;
while( c != '\n' && !feof(in) )
{
if ( c == '@' )
printf("\n\t @ is illegal charactor");
else
newline[i++] = c;
c = (char)fgetc(in);
}
if( feof( in ) )
{
printf("\n\t the file has been end!\n");
}
else if ( i >= MAXLEN)
{
printf("\n\t too long word in a line!\n");
}
newline[i] = '\0';
return newline;
}
char fetch() //从缓冲区中取字符
{
char c;
c = '@';
if ( *head != '\0' )
{
c = *head++;
}
return c;
}
int unfetch(int n)
{
int i = 0;
while( i < n )
{
head--;
if ( head == newline )
{
break;
}
i++;
}
return 0;
}
void dataproces()
{
char s[25];
int count = 0;
int d,d1,d2;
float f,f1,f2;
char c = fetch();
if ( c == '+' || c == '-' )
{
s[count++] = c;
c = fetch();
}
while( isdigit(c))
{
s[count++] = c;
c = fetch();
}
if ( isspace( c ) )
{
s[count] = '\0';
d = atoi(s);
d = fill_flagtab_int(d);
fprintf( out, "\n(%d,%d)", 35, d );
}
else if ( isalpha( c ) )//接收的是字母
{
if ( c == 'e' ) //带有指数
{
d = atoi(s); //前半部接收的是整数,
d1 = d;
c = fetch();
count = 0; //继续接收后半部，将下标置为 0，以从缓冲头部开始存入
if (c == '+' || c == '-')
{
s[count++] =c;
c = fetch();
}
while( isdigit(c) )
{
s[count++] = c;
c = fetch();
}
if ( isspace( c ) )
{
s[count] = '\0';
d = atoi( s );
d2 = d;
f = (float)pow(d1,d2);
d = fill_flagtab_float(f);
fprintf( out, "\n(%d,%d)", 36, d);
}
else if ( c == '.')
{
s[count++] = c;
c = fetch();
while( isdigit( c ))
{
s[count++] = c;
c = fetch();
}
unfetch(1);
s[count] = '\0';
f = ( float ) atof(s);
f2 = f;
f = (float)pow(d1,f2);
d = fill_flagtab_float(f);
fprintf( out, "\n(36,%d)", d);
}
else
{
unfetch(1);
s[count] = '\0';
d = atoi(s);
d = fill_flagtab_int(d);
fprintf(out,"\n(35,%d)",d);
}
}
else //所接收的字母不是 e，而是其他字母，则缓冲指针后退1个，且打印token
{
unfetch(1);
s[count] = '\0';
d = atoi( s );
d = fill_flagtab_int(d);
fprintf( out, "\n(%d,%d)", 35, d );
}
}
else if ( c == '.') //前半部接收的将是实数
{
s[count++] = c;
c = fetch();
while( isdigit(c))
{
s[count++] = c;
c = fetch();
}
if ( isspace( c ) )
{
s[count] = '\0';
f = (float)atof(s);
d = fill_flagtab_float(f);
fprintf( out, "\n(%d,%d)", 36, d );
}
else if( isalpha( c ) )//接收的是字母
{
if ( c == 'e' )//带有指数
{
f = ( float )atof(s);
f1 = f;
c = fetch();
count = 0; //继续接收后半部，将下标置为 0，以从缓冲头部开始存入
if ( c == '+' || c == '-' )
s[count++] =c;
c = fetch();
while( isdigit(c) )
{
s[count++] = c;
c = fetch();
}
if ( isspace( c ) )
{
s[count] = '\0';
d = atoi( s );
d2 = d;
f = (float)pow(f1,d2);
d = fill_flagtab_float(f);
fprintf( out, "\n(36,%d)", d );
}
else if ( c == '.') //指数后半部为浮点数
{
s[count] = '.';
c = fetch();
while( isdigit( c ))
{
s[count++] = c;
c = fetch();
}
s[count] = '\0';
f = ( float ) atof(s);
f2 = f;
f = (float)pow(f1,f2);
d = fill_flagtab_float(f);
fprintf(out,"\n(36,%d)",d);
unfetch(1);
}
else
{
unfetch(1);
s[count] = '\0';
d = atoi(s);
d2 = d;
f = (float)pow(f1,d2);
d = fill_flagtab_float(f);
fprintf( out, "\n(36,%d)", d );
}
}
else //不是指数标志e,而是其他字母则将浮点数打印，同时缓冲退1个
{
s[count] = '\0';
f = (float)atof( s );
d = fill_flagtab_float(f);
fprintf( out, "\n(%d,%d)", 36, d );
unfetch(1);
}
}
else //既不是数字，也不是字母，则将浮点数打印，同时缓冲退1个
{
if ( c != '@' && !isspace( c ) )
{
unfetch(1);
}
s[count] = '\0';
f = (float)atof( s );
d = fill_flagtab_float(f);
fprintf( out, "\n(%d,%d)", 36, d );
}
}
else //既不是数字，也不是字母，也不是小数点，则为整数打印，同时缓冲退1个
{
if ( c != '@' && !isspace( c ) )
{
unfetch(1);
}
s[count] = '\0';
d = ( int )atoi( s );
d = fill_flagtab_int(d);
fprintf( out, "\n(%d,%d)", 35, d );
}
}
int char_process()
{
int i = 0;
char c,temp[6];
while( (c = fetch()) != '\'')
{
temp[i++] = c;
}
temp[i] = '\0';
i = fill_flagtab_char( temp );
fprintf(out,"\n(%d,%d)",37,i);
return 1;
}
int fill_flagtab_char(char *temp)
{
int i = 0;
FLAGTAB[f_amount].type = int_num;
while( temp[i] !='\0' )
{
FLAGTAB[f_amount].val.val_char[i] = temp[i++];
}
f_amount++;
return f_amount - 1;
}
int fill_flagtab_int(int temp)
{
FLAGTAB[f_amount].type = int_num;
FLAGTAB[f_amount++].val.val_int = temp;
return f_amount - 1;
}
int fill_flagtab_float(float temp)
{
FLAGTAB[f_amount++].val.val_float = temp;
return f_amount - 1;
}
int fill_flagtab_bool(bool temp)
{
if (temp)
FLAGTAB[f_amount++].val.val_bool = true;
else
FLAGTAB[f_amount++].val.val_bool = false;
return f_amount - 1;
}
int symproces()
{
char c = fetch();
char nextc;
short int value = 0;
short int state = 0;
switch (c)
{
case '\'':
value = 38;
state = 0;
break;
case '(':
value = 39;
state = 0;
break;
case ')':
value = 40;
state = 0;
break;
case '+':
value = 43;
state = 0;
break;
case ',':
value = 44;
state = 0;
break;
case '-':
value = 45;
state = 0;
break;
case ';':
value = 52;
state = 0;
break;
case '=':
value = 56;
state = 0;
break;
case '[':
value = 59;
state = 0;
break;
case ']':
value = 60;
state = 0;
break;
default:
state = 1;
break;
}
if ( state == 0 )
{
fprintf(out,"\n(%d,%c)",value,32);
}
else if ( state ==1 )
{
nextc = fetch();
if ( c == '.')
{
if ( nextc == '.')
value = 47; // ..
else if ( nextc == '@')
{
value = 46;
}
else
{
unfetch(1); //从@回退到.(从nextc回退)
value = 46;
}
}
else if ( c == '/')
{
if ( nextc == '*')
{
value = 49;
while ( *head != '\0' ) //检验 /* & */ 的封闭性
{
if( *head++ == '*' && *head =='/')
{
value = 42;
head++;
return 0;
}
}
if ( *head == '\0')
{
printf(" /* & */ is not fit");
return 0;
}
}
else if ( nextc == '@')
{
value = 48;
}
else
{
unfetch(1);
value = 48;
}
}
else if ( c == '*')
{
if (nextc == '/')
{
value = 42;
}
else if ( nextc == '@')
value = 41;
else
{
ungetch(1);
value = 41;
}
}
else if ( c == ':' )
{
if ( nextc == '=' )
value = 51;
else if ( nextc == '@')
{
value = 50;
}
else
{
unfetch(1);
value = 50;
}
}
else if ( c == '<')
{
if ( nextc == '=')
value = 54;
else if (nextc == '>')
value =55;
else if ( nextc == '@')
{
value = 53;
}
else
{
unfetch(1);
value = 53;
}
}
else if ( c == '>')
{
if ( nextc == '=' )
value =58;
else if ( nextc == '@')
{
value = 57;
}
else
{
unfetch (1);
value = 57;
}
}
if ( value == 0 ) //非法字符
{
printf("illegal alpha");
}
else
fprintf(out,"\n(%d,%c)",value,32);
}
return 0;
}
void alfaproces()
{
char c = fetch();
short unsigned int i = 0;
char s[SIZE];
int ID = 0;
while( isalpha (c) || isdigit( c ) )
{
s[i++] = c;
if ( i > SIZE )
{
printf("\n\t the length of flag can't beyond 10\n");
break;
}
c = fetch();
}
s[i] = '\0';
if ( c!= '@' && !isspace( c ) )
{
unfetch(1);
}
ID = searchkeyID(s);
if ( !ID )
{
searchflag(s);
}
else
{
fprintf(out,"\n(%d,%c)",ID,32);
}
}
int searchkeyID(char *s)
{
int left = 0 ;
int right = 32;
int midle = 0;
while( left <= right )
{
midle = (left + right)/2;
if ( strcmp(s,keyword[midle].word) < 0)
{
right = midle - 1;
}
else if ( strcmp(s,keyword[midle].word) > 0 )
{
left = midle + 1;
}
else
{
break;
}
}
if (left > right)
return 0;
else
return keyword[midle].ID;
}
void searchflag( char *s )
{
short unsigned int i = 0;
while ( i < f_amount )
{
if( !strcmp (s,FLAGTAB[i].name ) ) //找到标示符
{
fprintf(out,"\n(%d,%d)",34,i);
break;
}
else
{
i++;
}
}
if ( i >= f_amount )//没有找到标示符
{
strcpy( FLAGTAB[i].name, s ); //插入
f_amount++;
fprintf(out,"\n(%d,%d)",34,i);
}
}