GI.GLib.Structs.HashTableIter

A GHashTableIter structure represents an iterator that can be used to iterate over the elements of a HashTable. GHashTableIter structures are typically allocated on the stack and then initialized with hashTableIterInit.

The iteration order of a HashTableIter over the keys/values in a hash table is not defined.

Exported types

newtype HashTableIter

Memory-managed wrapper type.

Constructors

HashTableIter (ManagedPtr HashTableIter)

Instances

Eq HashTableIter

Defined in GI.GLib.Structs.HashTableIter

Methods

(==) :: HashTableIter -> HashTableIter -> Bool

(/=) :: HashTableIter -> HashTableIter -> Bool

BoxedPtr HashTableIter

Defined in GI.GLib.Structs.HashTableIter

Methods

boxedPtrCopy :: HashTableIter -> IO HashTableIter

boxedPtrFree :: HashTableIter -> IO ()

CallocPtr HashTableIter

Defined in GI.GLib.Structs.HashTableIter

Methods

boxedPtrCalloc :: IO (Ptr HashTableIter)

ManagedPtrNewtype HashTableIter

Defined in GI.GLib.Structs.HashTableIter

Methods

toManagedPtr :: HashTableIter -> ManagedPtr HashTableIter

tag ~ 'AttrSet => Constructible HashTableIter tag

Defined in GI.GLib.Structs.HashTableIter

Methods

new :: MonadIO m => (ManagedPtr HashTableIter -> HashTableIter) -> [AttrOp HashTableIter tag] -> m HashTableIter

newZeroHashTableIter :: MonadIO m => m HashTableIter

Construct a HashTableIter struct initialized to zero.

Methods

Click to display all available methods, including inherited ones

Methods

init, next, remove, replace, steal.

Getters

None.

Setters

None.

init

hashTableIterInit

Arguments

:: (HasCallStack, MonadIO m)

=> HashTableIter

iter: an uninitialized HashTableIter

-> Map (Ptr ()) (Ptr ())

hashTable: a HashTable

-> m ()

Initializes a key/value pair iterator and associates it with hashTable. Modifying the hash table after calling this function invalidates the returned iterator.

The iteration order of a HashTableIter over the keys/values in a hash table is not defined.

C code

GHashTableIter iter;
gpointer key, value;

g_hash_table_iter_init (&iter, hash_table);
while (g_hash_table_iter_next (&iter, &key, &value))
  {
    // do something with key and value
  }

Since: 2.16

next

hashTableIterNext

Arguments

:: (HasCallStack, MonadIO m)

=> HashTableIter

iter: an initialized HashTableIter

-> m (Bool, Ptr (), Ptr ())

Returns: False if the end of the HashTable has been reached.

Advances iter and retrieves the key and/or value that are now pointed to as a result of this advancement. If False is returned, key and value are not set, and the iterator becomes invalid.

Since: 2.16

remove

hashTableIterRemove

Arguments

:: (HasCallStack, MonadIO m)

=> HashTableIter

iter: an initialized HashTableIter

-> m ()

Removes the key/value pair currently pointed to by the iterator from its associated HashTable. Can only be called after hashTableIterNext returned True, and cannot be called more than once for the same key/value pair.

If the HashTable was created using g_hash_table_new_full(), the key and value are freed using the supplied destroy functions, otherwise you have to make sure that any dynamically allocated values are freed yourself.

It is safe to continue iterating the HashTable afterward:

C code

while (g_hash_table_iter_next (&iter, &key, &value))
  {
    if (condition)
      g_hash_table_iter_remove (&iter);
  }

Since: 2.16

replace

hashTableIterReplace

Arguments

:: (HasCallStack, MonadIO m)

=> HashTableIter

iter: an initialized HashTableIter

-> Ptr ()

value: the value to replace with

-> m ()

Replaces the value currently pointed to by the iterator from its associated HashTable. Can only be called after hashTableIterNext returned True.

If you supplied a valueDestroyFunc when creating the HashTable, the old value is freed using that function.

Since: 2.30

steal

hashTableIterSteal

Arguments

:: (HasCallStack, MonadIO m)

=> HashTableIter

iter: an initialized HashTableIter

-> m ()

Removes the key/value pair currently pointed to by the iterator from its associated HashTable, without calling the key and value destroy functions. Can only be called after hashTableIterNext returned True, and cannot be called more than once for the same key/value pair.

Since: 2.16