/* Analyze the exponential part of a real number.  */
static char* expValue(char *ptr)
/* Analyze the exponential part of a real number.  */
static char* expValue(char *ptr)
{
    if (*ptr == '-' || *ptr == '+')
        ++ptr;
    if (!isdigit((int)(*ptr)))
        return 0;
    ptr = goNum(++ptr);
    return ptr;
}