diff --git a/include/tlibc/collections/HashMap.h b/include/tlibc/collections/HashMap.h
index a7f0514..2a68b9b 100755
--- a/include/tlibc/collections/HashMap.h
+++ b/include/tlibc/collections/HashMap.h
@@ -29,6 +29,8 @@ typedef struct HashMap_ {
 #define HashMap_construct(PTR, T, VALUE_DESTRUCTOR) HashMap_construct_size(PTR, sizeof(T), VALUE_DESTRUCTOR)
 void HashMap_construct_size(HashMap_* ptr, u32 value_t_size, FreeFunction NULLABLE(value_destructor));
 void HashMap_destroy(HashMap_* ptr);
-void* NULLABLE(HashMap_tryGetPtr)(HashMap_* ptr, str key);
-bool HashMap_tryPush(HashMap_* ptr, str key, void* value_ptr);
-bool HashMap_tryDelete(HashMap_* ptr, str key);
+
+bool HashMap_tryPush(HashMap_* ptr, const str key, void* value_ptr);
+void HashMap_pushOrUpdate(HashMap_* ptr, const str key, void* value_ptr);
+NULLABLE(void*) HashMap_tryGetPtr(const HashMap_* ptr, const str key);
+bool HashMap_tryDelete(HashMap_* ptr, const str key);
diff --git a/src/collections/HashMap.c b/src/collections/HashMap.c
index 16a6e77..54ae1a0 100755
--- a/src/collections/HashMap.c
+++ b/src/collections/HashMap.c
@@ -62,7 +62,7 @@ typedef struct BucketAndIndex {
 
 ///@returns `HashMapBucket*` for specified key or NULL, if table hasn't been allocated yet;
 /// Index of existing item with the same key or -1 if no item is present.
-static BucketAndIndex __HashMap_search(HashMap_* ptr, str key, u32 hash){
+static BucketAndIndex __HashMap_search(const HashMap_* ptr, const str key, u32 hash){
     if(ptr->height == 0)
         return BucketAndIndex_null;
 
@@ -79,7 +79,7 @@ static BucketAndIndex __HashMap_search(HashMap_* ptr, str key, u32 hash){
     return r;
 }
 
-void* NULLABLE(HashMap_tryGetPtr)(HashMap_* ptr, str key){
+void* HashMap_tryGetPtr(const HashMap_* ptr, const str key){
     u32 hash = __HashMap_HASH_FUNC(key);
     BucketAndIndex r = __HashMap_search(ptr, key, hash);
     // key not found
@@ -121,7 +121,7 @@ static void __HashMap_expand(HashMap_* ptr){
     ptr->height_n = height_expanded_n;
 }
 
-bool HashMap_tryPush(HashMap_* ptr, str key, void* value_ptr){
+bool HashMap_tryPush(HashMap_* ptr, const str key, void* value_ptr){
     u32 hash = __HashMap_HASH_FUNC(key);
     BucketAndIndex r = __HashMap_search(ptr, key, hash);
     // found existing item with the same key
@@ -140,7 +140,27 @@ bool HashMap_tryPush(HashMap_* ptr, str key, void* value_ptr){
     return true;
 }
 
-bool HashMap_tryDelete(HashMap_* ptr, str key){
+void HashMap_pushOrUpdate(HashMap_* ptr, const str key, void* value_ptr){
+    u32 hash = __HashMap_HASH_FUNC(key);
+    BucketAndIndex r = __HashMap_search(ptr, key, hash);
+    // found existing item with the same key
+    if(r.i != -1){
+        void* existing_item = ((u8*)r.bu->value_list.data) + r.i * ptr->value_t_size;
+        memcpy(existing_item, value_ptr, ptr->value_t_size);
+    }
+
+    HashMapBucket* bu = r.bu;
+    if(bu == NULL || List_len(&bu->key_hash_list, KeyHash) >= __HashMapBucket_MAX_LEN){
+        __HashMap_expand(ptr);
+        bu = &ptr->table[hash % ptr->height];
+    }
+    
+    KeyHash kh = { .key = str_copy(key), .hash = hash };
+    List_push(&bu->key_hash_list, KeyHash, kh);
+    List_push_size(&bu->value_list, value_ptr, ptr->value_t_size);
+}
+
+bool HashMap_tryDelete(HashMap_* ptr, const str key){
     u32 hash = __HashMap_HASH_FUNC(key);
     BucketAndIndex r = __HashMap_search(ptr, key, hash);
     // key not found