list.h

#ifndef LIST_H
# define LIST_H
/**
 ** Structure of a list, NULL is considered as an empty list.
**/
struct list
{
   void        *data;
   struct list *next;
};

/**
 ** Applies the function <fn> on all elements of the list.
**/
void list_foreach(const struct list *l, void (*fn)(const void *));

/**
 ** Free the list (but not the elements contained in it).
**/
void list_free(struct list *l);

/**
 ** Add an element to the head of the list.
**/
struct list *list_add(struct list *l, void *e);

/**
 ** Find an element in the list. Returns the list beginning by this element.
 ** If the element is not found, returns NULL.
**/
const struct list *list_find(const struct list *l,
                       const void *e,
                       int(*cmp_fn)(const void *left, const void *right));

/**
 ** Applies the function <map_fn> on the list. Returns a new list with the
 ** new values.
**/
struct list *list_map(const struct list *l, void *(map_fn)(const void *));

/**
 ** Copies a list. This function does not copy the list data.
**/
struct list *list_copy(const struct list *l, struct list **tail);

/**
 ** Flatten a list of list (change the depth of a list from n to n - 1) and
 ** then returns the new list.
**/
struct list *list_flatten(const struct list *l);

/**
 ** Applies the function <map_fn> on all elements of the list, then flatten
 ** it. The temporary list must be freed using the <free_internal_mapped_list_fn>
 ** function. The function returns the new list.
**/
struct list *list_flatmap(const struct list *l,
                          void *(*map_fn)(const void *),
                          void (*free_internal_mapped_list_fn)(void *));

/**
 ** Returns a new list with all elements complying with the <predicate_fn>
 ** function.
**/
struct list *list_filter(const struct list *l,
                         int (*predicate_fn)(const void *));

/**
 ** Reduce the list to a single element using the <reduce_fn> function. If the
 ** list is null, <init> must be return.
**/
void *list_reduce(struct list *l,
                  void *init,
                  void *(*reduce_fn)(const void *element, void *accumulator));

#endif /* ! LIST_H */