merging in aegis' JNI bindings

src/datastructures.c

@@ -41,6 +41,26 @@ HSlist* h_slist_new(HArena *arena) {
   return ret;
 }
 
+HSlist* h_slist_copy(HSlist *slist) {
+  HSlist *ret = h_slist_new(slist->arena);
+  HSlistNode *head = slist->head;
+  HSlistNode *tail;
+  if (head != NULL) {
+    h_slist_push(ret, head->elem);
+    tail = ret->head;
+    head = head->next;
+  }
+  while (head != NULL) {
+    // append head item to tail in a new node
+    HSlistNode *node = h_arena_malloc(slist->arena, sizeof(HSlistNode));
+    node->elem = head->elem;
+    node->next = NULL;
+    tail = tail->next = node;
+    head = head->next;
+  }
+  return ret;
+}
+
 void* h_slist_pop(HSlist *slist) {
   HSlistNode *head = slist->head;
   if (!head)