Use const where applicable to allow for const data structures.

include/ht.h

@@ -124,7 +124,7 @@ libds_result ht_put(ht* ht, const void* key, void* value);
  * @param key the key to use to find the data.
  * @return the data, or NULL if it is not found.
  */
-void* ht_get(ht* ht, const void* key);
+void* ht_get(const ht* ht, const void* key);
 /**
  * Retreives the first value from the hash table
  * that's stored with the given key and passes the compare function.
@@ -134,7 +134,7 @@ void* ht_get(ht* ht, const void* key);
  * @param compare the comparison function used to compare adta.
  * @return the data, or NULL if it is not found.
  */
-void* ht_find(ht* ht, const void* key, void* data, compare_func compare);
+void* ht_find(const ht* ht, const void* key, void* data, compare_func compare);
 /**
  * Removes a value from the hash table.
  * @param ht the hash table to remove a value from.
@@ -154,6 +154,6 @@ void ht_remove(ht* ht, const void* key);
  * @param ... variable arguments to be passed to the foreach function.
  * @return the code returned by the foreach functions.
  */
-int ht_foreach(ht* ht, void* data, compare_func compare, foreach_func foreach, ...);
+int ht_foreach(const ht* ht, void* data, compare_func compare, foreach_func foreach, ...);
 
 #endif

include/ll.h

@@ -82,7 +82,7 @@ void ll_remove(ll* ll, void* data);
  * @param compare the comparison function
  * @return the first element that is matched by the comparison function, or NULL if none are matched.
  */
-void* ll_find(ll* ll, void* data, compare_func compare);
+void* ll_find(const ll* ll, void* data, compare_func compare);
 /**
  * Runs through every element in the linked list, and compares it against the
  * given data using the given comparison function. If the comparison function returns
@@ -95,20 +95,20 @@ void* ll_find(ll* ll, void* data, compare_func compare);
  * @param ... variable arguments to be passed on to the foreach function
  * @return 0 if all goes well, or the first nonzero code returned by foreach.
  */
-int ll_foreach(ll* ll, void* data, compare_func compare, foreach_func foreach, ...);
+int ll_foreach(const ll* ll, void* data, compare_func compare, foreach_func foreach, ...);
 
 /**
  * Gets the element at the beginning of the linked list.
  * @param ll the linked list to get the data from.
  * @return the element at the beginning of the element, or NULL if there is none.
  */
-void* ll_head(ll* ll);
+void* ll_head(const ll* ll);
 /**
 * Gets the element at the end of the linked list.
 * @param ll the linked list to get the data from.
 * @return the element at the end of the element, or NULL if there is none.
 */
-void* ll_tail(ll* ll);
+void* ll_tail(const ll* ll);
 /**
  * Removes the element at the beginning of the linked list,
  * and returns it.

include/sprs.h

@@ -111,7 +111,7 @@ libds_result sprs_put_grow(sprs* sprs, size_t index, void* data);
  * @param index the index for which to check.
  * @return 1 if the index exists, 0 if not.
  */
-int sprs_contains(sprs* sprs, size_t index);
+int sprs_contains(const sprs* sprs, size_t index);
 /**
  * Gets the value stored under the given sparse set index.
  * This will check for whether the index is in the sparse set first,
@@ -123,7 +123,7 @@ int sprs_contains(sprs* sprs, size_t index);
  * @param index the index from under which to retrieve the value.
  * @return the value stored under the index, or NULL if there is nothing there.
  */
-void* sprs_get(sprs* sprs, size_t index);
+void* sprs_get(const sprs* sprs, size_t index);
 
 /**
  * Runs through every element in the sparse set, and compares it against the
@@ -135,7 +135,7 @@ void* sprs_get(sprs* sprs, size_t index);
  * @param compare the comparison function
  * @return the first element that is matched by the comparison function, or NULL if none are matched.
  */
-void* sprs_find(sprs* sprs, void* data, compare_func compare);
+void* sprs_find(const sprs* sprs, void* data, compare_func compare);
 /**
  * Runs through every element in the sparse set, and compares it against the
  * given data using the given comparison function. If the comparison function returns
@@ -148,6 +148,6 @@ void* sprs_find(sprs* sprs, void* data, compare_func compare);
  * @param ... variable arguments to be passed on to the foreach function
  * @return 0 if all goes well, or the first nonzero code returned by foreach.
  */
-int sprs_foreach(sprs* sprs, void* data, compare_func compare, foreach_func foreach, ...);
+int sprs_foreach(const sprs* sprs, void* data, compare_func compare, foreach_func foreach, ...);
 
 #endif

include/vec.h

@@ -67,7 +67,7 @@ void vec_remove(vec* vec, void* val);
  * @param compare the comparison function
  * @return the first element that is matched by the comparison function, or NULL if none are matched.
  */
-void* vec_find(vec* vec, void* data, compare_func compare);
+void* vec_find(const vec* vec, void* data, compare_func compare);
 /**
  * Runs through every element in the vector, and compares it against the
  * given data using the given comparison function. If the comparison function returns
@@ -80,7 +80,7 @@ void* vec_find(vec* vec, void* data, compare_func compare);
  * @param ... variable arguments to be passed on to the foreach function
  * @return 0 if all goes well, or the first nonzero code returned by foreach.
  */
-int vec_foreach(vec* vec, void* data, compare_func compare, foreach_func foreach, ...);
+int vec_foreach(const vec* vec, void* data, compare_func compare, foreach_func foreach, ...);
 
 /**
  * Gets the value at the given index of the vector.
@@ -88,7 +88,7 @@ int vec_foreach(vec* vec, void* data, compare_func compare, foreach_func foreach
  * @param index the index to retreive a value from
  * @return pointer to the value, or, if the index is out of bounds (or there is nothing there) NULL.
  */
-void* vec_index(vec* vec, size_t index);
+void* vec_index(const vec* vec, size_t index);
 /**
  * Clears the vector, removing all elements from it
  * but not resizing it down.

src/ht.c

@@ -69,7 +69,7 @@ libds_result ht_put(ht* ht, const void* key, void* data) {
 
   return result;
 }
-void* ht_get(ht* ht, const void* key) {
+void* ht_get(const ht* ht, const void* key) {
   void* data = NULL;
   ht_node* search_node;
   unsigned long key_int = ht->hash_func(key) % LIBDS_HT_SIZE;
@@ -84,7 +84,7 @@ void* ht_get(ht* ht, const void* key) {
 
   return data;
 }
-void* ht_find(ht* ht, const void* key, void* data, compare_func compare) {
+void* ht_find(const ht* ht, const void* key, void* data, compare_func compare) {
   void* found = NULL;
   ht_node* search_node;
   unsigned long key_int = ht->hash_func(key) % LIBDS_HT_SIZE;
@@ -116,7 +116,7 @@ void ht_remove(ht* ht, const void* key) {
   }
 }
 
-int ht_foreach(ht* ht, void* data, compare_func compare, foreach_func foreach,
+int ht_foreach(const ht* ht, void* data, compare_func compare, foreach_func foreach,
                ...) {
   int index = 0;
   int return_code = 0;

src/ll.c

@@ -62,7 +62,7 @@ void ll_remove(ll* ll, void* data) {
   }
 }
 
-void* ll_find(ll* ll, void* data, compare_func compare) {
+void* ll_find(const ll* ll, void* data, compare_func compare) {
   void* to_return = NULL;
   ll_node* head = ll->head;
   while (head && to_return == NULL) {
@@ -73,7 +73,7 @@ void* ll_find(ll* ll, void* data, compare_func compare) {
   }
   return to_return;
 }
-int ll_foreach(ll* ll, void* data, compare_func compare, foreach_func foreach,
+int ll_foreach(const ll* ll, void* data, compare_func compare, foreach_func foreach,
                ...) {
   int return_code = 0;
   ll_node* head = ll->head;
@@ -89,8 +89,8 @@ int ll_foreach(ll* ll, void* data, compare_func compare, foreach_func foreach,
   return return_code;
 }
 
-void* ll_head(ll* ll) { return ll->head ? ll->head->data : NULL; }
-void* ll_tail(ll* ll) { return ll->tail ? ll->tail->data : NULL; }
+void* ll_head(const ll* ll) { return ll->head ? ll->head->data : NULL; }
+void* ll_tail(const ll* ll) { return ll->tail ? ll->tail->data : NULL; }
 void* ll_pophead(ll* ll) {
   void* to_return = NULL;
   if (ll->head) {

src/sprs.c

@@ -70,17 +70,17 @@ libds_result sprs_put_grow(sprs* sprs, size_t index, void* data) {
   }
   return result;
 }
-int sprs_contains(sprs* sprs, size_t index){
+int sprs_contains(const sprs* sprs, size_t index){
   return sprs->sparse[index].index < sprs->size && sprs->dense[sprs->sparse[index].index] == index;
 }
-void* sprs_get(sprs* sprs, size_t index){
+void* sprs_get(const sprs* sprs, size_t index){
   void* data = NULL;
   if(sprs_contains(sprs, index)){
     data = sprs->sparse[index].data;
   }
   return data;
 }
-void* sprs_find(sprs* sprs, void* data, compare_func compare){
+void* sprs_find(const sprs* sprs, void* data, compare_func compare){
   int index = 0;
   void* to_return = NULL;
   for(; index < sprs->size && to_return == NULL; index++){
@@ -90,7 +90,7 @@ void* sprs_find(sprs* sprs, void* data, compare_func compare){
   }
   return to_return;
 }
-int sprs_foreach(sprs* sprs, void* data, compare_func compare, foreach_func foreach, ...){
+int sprs_foreach(const sprs* sprs, void* data, compare_func compare, foreach_func foreach, ...){
   int index = 0;
   int return_code = 0;
   va_list args;

src/vec.c

@@ -61,7 +61,7 @@ void vec_remove(vec* v, void* data) {
   }
 }
 
-void* vec_find(vec* v, void* data, compare_func compare) {
+void* vec_find(const vec* v, void* data, compare_func compare) {
   size_t index = 0;
   void* found = NULL;
   void** data_array = v->data;
@@ -73,7 +73,7 @@ void* vec_find(vec* v, void* data, compare_func compare) {
   }
   return found;
 }
-int vec_foreach(vec* v, void* data, compare_func compare, foreach_func foreach,
+int vec_foreach(const vec* v, void* data, compare_func compare, foreach_func foreach,
                 ...) {
   size_t index = 0;
   int return_code = 0;
@@ -90,7 +90,7 @@ int vec_foreach(vec* v, void* data, compare_func compare, foreach_func foreach,
   return return_code;
 }
 
-void* vec_index(vec* v, size_t index) {
+void* vec_index(const vec* v, size_t index) {
   void* to_return = NULL;
   if (index < v->capacity) {
     to_return = ((void**) v->data)[index];