rust/src/lib/_str.rs

import rustrt.sbuf;

import std._vec.rustrt.vbuf;

native "rust" mod rustrt {
  type sbuf;
  fn str_buf(str s) -> sbuf;
  fn str_byte_len(str s) -> uint;
  fn str_alloc(uint n_bytes) -> str;
  fn str_from_vec(vec[u8] b) -> str;
  fn refcount[T](str s) -> uint;
}

fn eq(&str a, &str b) -> bool {
  let uint i = byte_len(a);
  if (byte_len(b) != i) {
    ret false;
  }
  while (i > 0u) {
    i -= 1u;
    auto cha = a.(i);
    auto chb = b.(i);
    if (cha != chb) {
      ret false;
    }
  }
  ret true;
}

fn hash(&str s) -> uint {
  // djb hash.
  // FIXME: replace with murmur.
  let uint u = 5381u;
  for (u8 c in s) {
    u *= 33u;
    u += (c as uint);
  }
  ret u;
}

fn is_utf8(vec[u8] v) -> bool {
  fail; // FIXME
}

fn is_ascii(str s) -> bool {
  let uint i = byte_len(s);
  while (i > 0u) {
    i -= 1u;
    if ((s.(i) & 0x80u8) != 0u8) {
      ret false;
    }
  }
  ret true;
}

fn alloc(uint n_bytes) -> str {
  ret rustrt.str_alloc(n_bytes);
}

// Returns the number of bytes (a.k.a. UTF-8 code units) in s.
// Contrast with a function that would return the number of code
// points (char's), combining character sequences, words, etc.  See
// http://icu-project.org/apiref/icu4c/classBreakIterator.html for a
// way to implement those.
fn byte_len(str s) -> uint {
  ret rustrt.str_byte_len(s);
}

fn buf(str s) -> sbuf {
  ret rustrt.str_buf(s);
}

fn bytes(str s) -> vec[u8] {
  /* FIXME (issue #58):
   * Should be...
   *
   *  fn ith(str s, uint i) -> u8 {
   *      ret s.(i);
   *  }
   *  ret _vec.init_fn[u8](bind ith(s, _), byte_len(s));
   *
   * but we do not correctly decrement refcount of s when
   * the binding dies, so we have to do this manually.
   */
  let uint n = _str.byte_len(s);
  let vec[u8] v = _vec.alloc[u8](n);
  let uint i = 0u;
  while (i < n) {
    v += vec(s.(i));
    i += 1u;
  }
  ret v;
}

fn from_bytes(vec[u8] v) : is_utf8(v) -> str {
  ret rustrt.str_from_vec(v);
}

fn refcount(str s) -> uint {
  // -1 because calling this function incremented the refcount.
  ret rustrt.refcount[u8](s) - 1u;
}


// Standard bits from the world of string libraries.

fn index(str s, u8 c) -> int {
  let int i = 0;
  for (u8 k in s) {
    if (k == c) {
      ret i;
    }
    i += 1;
  }
  ret -1;
}

fn rindex(str s, u8 c) -> int {
  let int n = _str.byte_len(s) as int;
  while (n >= 0) {
    if (s.(n) == c) {
      ret n;
    }
    n -= 1;
  }
  ret n;
}

fn find(str haystack, str needle) -> int {

  let int haystack_len = byte_len(haystack) as int;
  let int needle_len = byte_len(needle) as int;

  if (needle_len == 0) {
    ret 0;
  }

  fn match_at(&str haystack,
              &str needle,
              int i) -> bool {
    let int j = i;
    for (u8 c in needle) {
      if (haystack.(j) != c) {
        ret false;
      }
      j += 1;
    }
    ret true;
  }

  let int i = 0;
  while (i <= haystack_len - needle_len) {
    if (match_at(haystack, needle, i)) {
      ret i;
    }
    i += 1;
  }
  ret  -1;
}

fn substr(str s, uint begin, uint len) -> str {
  let str accum = "";
  let uint i = begin;
  while (i < begin+len) {
    accum += s.(i);
    i += 1u;
  }
  ret accum;
}

fn split(str s, u8 sep) -> vec[str] {
  let vec[str] v = vec();
  let str accum = "";
  let bool ends_with_sep = false;
  for (u8 c in s) {
    if (c == sep) {
      v += accum;
      accum = "";
      ends_with_sep = true;
    } else {
      accum += c;
      ends_with_sep = false;
    }
  }
  if (_str.byte_len(accum) != 0u ||
      ends_with_sep) {
    v += accum;
  }
  ret v;
}

fn concat(vec[str] v) -> str {
  let str s = "";
  for (str ss in v) {
    s += ss;
  }
  ret s;
}

fn connect(vec[str] v, str sep) -> str {
  let str s = "";
  let bool first = true;
  for (str ss in v) {
    if (first) {
      first = false;
    } else {
      s += sep;
    }
    s += ss;
  }
  ret s;
}


// Local Variables:
// mode: rust;
// fill-column: 78;
// indent-tabs-mode: nil
// buffer-file-coding-system: utf-8-unix
// compile-command: "make -k -C .. 2>&1 | sed -e 's/\\/x\\//x:\\//g'";
// End: