C++ SPString::length方法代码示例

int
SPString::rindex(const SPString & s, int offset)
{
  if (offset == -1)
    offset = length() - s.length();
  else
    offset = offset - s.length() + 1;
  if (offset > length() - s.length())
    offset = length() - s.length();

  for (int i = offset; i >= 0; i--) {
    if (strncmp(&pstr[i], s, s.length()) == 0)
      return i;
  }
  return -1;
}

int
SPString::index(const SPString & s, int offset)
{
  if (offset < 0)
    offset = 0;
  for (int i = offset; i < length(); i++) {
    if (strncmp(&pstr[i], s, s.length()) == 0)
      return i;
  }

  return -1;
}

//
// I know! This is not fast, but it works!!
//
int
SPString::tr(const char *sl, const char *rl, const char *opts)
{
  if (length() == 0 || strlen(sl) == 0)
    return 0;

  int         cflg = strchr(opts, 'c') != NULL; // thanks Michael
  int         dflg = strchr(opts, 'd') != NULL;
  int         sflg = strchr(opts, 's') != NULL;

  int         cnt = 0,
              flen = 0;
  unsigned int i;
  SPString    t;
  unsigned char lstc = '\0',
              fr[256];

  // build search array, which is a 256 byte array that stores the index+1
  // in the search string for each character found, == 0 if not in search
  memset(fr, 0, 256);
  for (i = 0; i < strlen(sl); i++) {
    if (i && sl[i] == '-') { // got a range
      assert(i + 1 < strlen(sl) && lstc <= sl[i + 1]);  // sanity check
      for (unsigned char c = lstc + 1; c <= sl[i + 1]; c++) {
        fr[c] = (unsigned char) ++flen;
      }
      i++;
      lstc = '\0';
    }
    else {
      lstc = sl[i];
      fr[sl[i]] = (unsigned char) ++flen;
    }
  }

  unsigned int rlen;

  // build replacement list
  if ((rlen = strlen(rl)) != 0) {
    for (i = 0; i < rlen; i++) {
      if (i && rl[i] == '-') {  // got a range
        assert(i + 1 < rlen && t[t.length() - 1] <= rl[i + 1]); // sanity check
        for (char c = t[i - 1] + 1; c <= rl[i + 1]; c++)
          t += c;
        i++;
      }
      else
        t += rl[i];
    }
  }

  // replacement string that is shorter uses last character for rest of
  // string
  // unless the delete option is in effect or it is empty
  while (!dflg && rlen && flen > t.length()) {
    t += t[t.length() - 1];  // duplicate last character
  }

  rlen = t.length();         // length of translation
  // string

  // do translation, and deletion if dflg (actually falls out of length of t)
  // also squeeze translated characters if sflg

  SPString    tmp;           // need this in case dflg, and string changes
  // size
  for (i = 0; i < (unsigned int) length(); i++) {
    unsigned int off;

    if (cflg) {              // complement, ie if NOT in
      // f
      char        rc = (!dflg && t.length() ? t[t.length() - 1] : '\0');  // always use last
      // character for
      // replacement
      if ((off = fr[(*this)[i]]) == 0) {  // not in map
        cnt++;
        if (!dflg && (!sflg || tmp.length() == 0 || tmp[tmp.length() - 1] != rc))
          tmp += rc;
      }
      else
        tmp += (*this)[i];   // just stays the same
    }
    else {                   // in fr so substitute with
      // t, if no equiv in t then
      // delete
      if ((off = fr[(*this)[i]]) > 0) {
        off--;
        cnt++;
        if (rlen == 0 && !dflg && (!sflg || tmp.length() == 0 || tmp[tmp.length() - 1] != (*this)[i]))
          tmp += (*this)[i]; // stays the same
        else if (off < rlen && (!sflg || tmp.length() == 0 || tmp[tmp.length() - 1] != t[off]))
          tmp += t[off];     // substitute
      }
      else
        tmp += (*this)[i];   // just stays the same
    }
  }
//.........这里部分代码省略.........