inspect

/*
 * Returns a string that represents the StringScanner object, showing:
 * - the current position
 * - the size of the string
 * - the characters surrounding the scan pointer
 *
 *   s = StringScanner.new("Fri Dec 12 1975 14:39")
 *   s.inspect            # -> '#<StringScanner 0/21 @ "Fri D...">'
 *   s.scan_until /12/    # -> "Fri Dec 12"
 *   s.inspect            # -> '#<StringScanner 10/21 "...ec 12" @ " 1975...">'
 */
static VALUE
strscan_inspect(VALUE self)
{
    struct strscanner *p;
    char buf[BUFSIZE];
    long len;
    VALUE a, b;

    Data_Get_Struct(self, struct strscanner, p);
    if (NIL_P(p->str)) {
        len = snprintf(buf, BUFSIZE, "#<%s (uninitialized)>",
                       rb_class2name(CLASS_OF(self)));
        return infect(rb_str_new(buf, len), p);
    }
    if (EOS_P(p)) {
        len = snprintf(buf, BUFSIZE, "#<%s fin>",
                       rb_class2name(CLASS_OF(self)));
        return infect(rb_str_new(buf, len), p);
    }
    if (p->curr == 0) {
        b = inspect2(p);
        len = snprintf(buf, BUFSIZE, "#<%s %ld/%ld @ %s>",
                       rb_class2name(CLASS_OF(self)),
                       p->curr, S_LEN(p),
                       RSTRING(b)->ptr);
        return infect(rb_str_new(buf, len), p);
    }
    a = inspect1(p);
    b = inspect2(p);
    len = snprintf(buf, BUFSIZE, "#<%s %ld/%ld %s @ %s>",
                   rb_class2name(CLASS_OF(self)),
                   p->curr, S_LEN(p),
                   RSTRING(a)->ptr,
                   RSTRING(b)->ptr);
    return infect(rb_str_new(buf, len), p);
}