MapKeys[K: K, V: V, H: HashFunction[K] val, M: HashMap[K, V, H] #read]
An iterator over the keys in a map.
class ref MapKeys[K: K, V: V, H: HashFunction[K] val, M: HashMap[K, V, H] #read] is Iterator[M->K] ref
Implements
- Iterator[M->K] ref
Constructors
create
Creates an iterator for the given map.
new ref create( map: M) : MapKeys[K, V, H, M] ref^
Parameters
- map: M
Returns
- MapKeys[K, V, H, M] ref^
Public Functions
has_next
True if it believes there are remaining entries. May not be right if values were added or removed from the map.
fun box has_next() : Bool val
Returns
- Bool val
next
Returns the next key, or raises an error if there isn't one. If keys are added during iteration, this may not return all keys.
fun ref next() : M->K ?
Returns
- M->K ?
© 2016-2020, The Pony Developers
© 2014-2015, Causality Ltd.
Licensed under the BSD 2-Clause License.
https://stdlib.ponylang.io/collections-MapKeys