list.c

#ifndef LIST_C
#define LIST_C

 #define LIST_DEFINE(type)                                          \
type##_list *type##_list_cons(type elt, type##_list *list)          \
{                                                                   \
  type##_list *res = malloc(sizeof (type##_list));                  \
  res->head = elt;                                                  \
  res->tail = list;                                                 \
  return res;                                                       \
}                                                                   \
                                                                    \
type##_list *type##_list_dest(type##_list *list)                    \
{                                                                   \
  type##_list *res = list->tail;                                    \
  free(list);                                                       \
  return res;                                                       \
}                                                                   \
                                                                    \
int type##_list_length(type##_list *list)                           \
{                                                                   \
  type##_list *tmp = list;                                          \
  unsigned length = 0;                                              \
  while (tmp)                                                       \
  {                                                                 \
    tmp = tmp->tail;                                                \
    ++length;                                                       \
  }                                                                 \
  return length;                                                    \
}                                                                   \
                                                                    \
type type##_list_head(type##_list *list)                            \
{                                                                   \
  return list->head;                                                \
}                                                                   \
                                                                    \
type##_list *type##_list_tail(type##_list *list)                    \
{                                                                   \
  return list->tail;                                                \
}                                                                   \
                                                                    \
type##_list *type##_list_append(type##_list *l1, type##_list *l2)   \
{                                                                   \
  if (!l1)                                                          \
    return l2;                                                      \
  type##_list *tmp = l1;                                            \
  while (tmp->tail)                                                 \
    tmp = tmp->tail;                                                \
  tmp->tail = l2;                                                   \
  return l1;                                                        \
}                                                                   \
                                                                    \
type type##_list_nth(type##_list *list, int pos)                    \
{                                                                   \
  while (pos-- > 0)                                                 \
    list = list->tail;                                              \
  return list->head;                                                \
}                                                                   \
                                                                    \
type##_list *type##_list_rev(type##_list *list)                     \
{                                                                   \
  if (!list)                                                        \
    return list;                                                    \
  type##_list *next = list->tail;                                   \
  list->tail = NULL;                                                \
  while (next)                                                      \
  {                                                                 \
    type##_list *tmp = next->tail;                                  \
    next->tail = list;                                              \
    list = next;                                                    \
    next = tmp;                                                     \
  }                                                                 \
  return list;                                                      \
}                                                                   \
                                                                    \
int type##_list_pos(type##_list *list, type elt)                    \
{                                                                   \
  unsigned pos = 0;                                                 \
  while (list && list->head != elt)                                 \
  {                                                                 \
    list = list->tail;                                              \
    ++pos;                                                          \
  }                                                                 \
  return list ? (int) pos : -1;                                     \
}                                                                   \

#endif /* !LIST_C */