yorick/hash.i

   1 // Implement our old naive O(n) map because Yeti's hash table (h_new()) cannot
   2 // be used inside arrays and structs (we can't get a pointer to hash table).
   3 // This prevents saving pointer to environment in MalFunction for example.
   4
   5 struct Hash {
   6   pointer keys
   7   pointer vals
   8 }
   9
  10 func hash_new(void)
  11 {
  12   return Hash(keys=&[], vals=&[])
  13 }
  14
  15 func hash_get(h, key)
  16 {
  17   for (i = 1; i <= numberof(*h.keys); ++i) {
  18     if ((*h.keys)(i) == key) return *((*h.vals)(i))
  19   }
  20   return nil
  21 }
  22
  23 func hash_has_key(h, key)
  24 {
  25   for (i = 1; i <= numberof(*h.keys); ++i) {
  26     if ((*h.keys)(i) == key) return 1
  27   }
  28   return 0
  29 }
  30
  31 func hash_set(&h, key, val)
  32 {
  33   if (is_void(*h.keys)) {
  34     h.keys = &[key]
  35     h.vals = &[&val]
  36     return
  37   }
  38   for (i = 1; i <= numberof(*h.keys); ++i) {
  39     if ((*h.keys)(i) == key) {
  40       (*h.vals)(i) = &val
  41       return
  42     }
  43   }
  44   tmp = *h.keys
  45   grow, tmp, [key]
  46   h.keys = &tmp
  47   tmp = *h.vals
  48   grow, tmp, [&val]
  49   h.vals = &tmp
  50 }
  51
  52 func hash_delete(&h, key)
  53 {
  54   if (is_void(*h.keys) || numberof(*h.keys) == 0) return
  55   k = *h.keys
  56   v = *h.vals
  57   if (numberof(k) == 1) {
  58     if (k(1) == key) {
  59       h.keys = &[]
  60       h.vals = &[]
  61       return
  62     }
  63   }
  64   for (i = 1; i <= numberof(k); ++i) {
  65     if (k(i) == key) {
  66       if (i == 1) {
  67         h.keys = &(k(i+1:))
  68         h.vals = &(v(i+1:))
  69       } else if (i == numberof(k)) {
  70         h.keys = &(k(1:i-1))
  71         h.vals = &(v(1:i-1))
  72       } else {
  73         h.keys = &grow(k(1:i-1), k(i+1:))
  74         h.vals = &grow(v(1:i-1), v(i+1:))
  75       }
  76       return
  77     }
  78   }
  79 }