static int ScanNumericLiteral()
{
int base = 10;
if('.' == *CURSOR)
{
return ScanFloatLiteral();
}
if('0' == *CURSOR && (CURSOR[1] == 'x'|| CURSOR[1] == 'X'))
{
base = 16;
CURSOR += 2;
while(IsHexDigit(*CURSOR))
{
CURSOR++;
}
}
else if('0' == *CURSOR)
{
base = 8;
CURSOR++;
while(IsOctDigit(*CURSOR))
{
CURSOR++;
}
}
else
{
CURSOR++;
while(IsDigit(*CURSOR))
{
CURSOR++;
}
}
if(base == 16 || (*CURSOR == '.' && *CURSOR == 'e' && *CURSOR == 'E'))
{
while('u' == *CURSOR || 'U' == *CURSOR ||
'l' == *CURSOR || 'L' == *CURSOR)
{
CURSOR++;
}
return TK_INTCONST;
}
else
{
return ScanFloatLiteral();
}
}
/* 扫描常数序列 */
static int ScanNumericLiteral (void)
{
unsigned char *start = CURRENT;
/* 表示数值是多少进制 */
unsigned char base = 10;
if ('.' == *CURRENT) {
return ScanFloatLiteral (start);
}
/* 扫描前半部分（小数点的左边） */
if ('0' == *CURRENT && ('x' == CURRENT[1] || 'X' == CURRENT[1])) {
base = 16;
start = (CURRENT += 2);
if (!IsHexDigit (*CURRENT)) {
Error (&TokenCoord, "Expect hex digit");
TokenValue.i[0] = 0;
return TK_INTCONST;
}
while (IsHexDigit (*CURRENT))
CURRENT++;
} else if ('0' == *CURRENT) {
base = 8;
while (IsOctDigit (*++CURRENT));
} else {
while (IsDigit (*++CURRENT));
}
/* 如果符合下边条件,按整形处理 */
if (16 == base || ('.' != *CURRENT && 'e' != *CURRENT && 'E' != *CURRENT))
return ScanIntLiteral (start, (int)(CURRENT - start), base);
else return ScanFloatLiteral (start);
}
/* 处理浮点常量和.../. 操作 */
static int ScanDot(void)
{
if (IsDigit(CURRENT[1])) {
return ScanFloatLiteral(CURRENT);
} else if (CURRENT[1] == '.' && CURRENT[2] == '.') {
CURRENT += 3;
return TK_ELLIPSE;
} else {
CURRENT++;
return TK_DOT;
}
}