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HashMap[K: Any #share, V: Any #share, H: HashFunction[K] val]
A persistent map based on the Compressed Hash Array Mapped Prefix-tree from 'Optimizing Hash-Array Mapped Tries for Fast and Lean Immutable JVM Collections' by Michael J. Steindorfer and Jurgen J. Vinju
Usage
use "collections/persistent"
actor Main
new create(env: Env) =>
try
let m1 = Map[String, U32] // {}
// Update returns a new map with the provided key set
// to the provided value. The old map is unchanged.
let m2 = m1("a") = 5 // {a: 5}
let m3 = m2("b") = 10 // {a: 5, b: 10}
let m4 = m3.remove("a")? // {b: 10}
// You can create a new map from key value pairs.
let m5 = Map[String, U32].concat([("a", 2); ("b", 3)].values()) // {a: 2, b: 3}
end
class val HashMap[K: Any #share, V: Any #share, H: HashFunction[K] val]
Constructors
create
new val create()
: HashMap[K, V, H] val^
Returns
- HashMap[K, V, H] val^
Public Functions
apply
Attempt to get the value corresponding to k.
fun val apply(
k: K)
: val->V ?
Parameters
- k: K
Returns
- val->V ?
size
Return the amount of key-value pairs in the Map.
fun val size()
: USize val
Returns
- USize val
update
Update the value associated with the provided key.
fun val update(
key: K,
value: val->V)
: HashMap[K, V, H] val
Parameters
- key: K
- value: val->V
Returns
- HashMap[K, V, H] val
remove
Try to remove the provided key from the Map.
fun val remove(
k: K)
: HashMap[K, V, H] val ?
Parameters
- k: K
Returns
- HashMap[K, V, H] val ?
get_or_else
Get the value associated with provided key if present. Otherwise, return the provided alternate value.
fun val get_or_else(
k: K,
alt: val->V)
: val->V
Parameters
- k: K
- alt: val->V
Returns
- val->V
contains
Check whether the node contains the provided key.
fun val contains(
k: K)
: Bool val
Parameters
- k: K
Returns
- Bool val
concat
Add the K, V pairs from the given iterator to the map.
fun val concat(
iter: Iterator[(val->K , val->V)] ref)
: HashMap[K, V, H] val
Parameters
- iter: Iterator[(val->K , val->V)] ref
Returns
- HashMap[K, V, H] val
add
Return this Map with the given (key, value) mapping.
fun val add(
key: K,
value: val->V)
: HashMap[K, V, H] val
Parameters
- key: K
- value: val->V
Returns
- HashMap[K, V, H] val
sub
Return this Map without the given key.
fun val sub(
key: K)
: HashMap[K, V, H] val
Parameters
- key: K
Returns
- HashMap[K, V, H] val
keys
fun val keys()
: MapKeys[K, V, H] ref
Returns
- MapKeys[K, V, H] ref
values
fun val values()
: MapValues[K, V, H] ref
Returns
- MapValues[K, V, H] ref
pairs
fun val pairs()
: MapPairs[K, V, H] ref
Returns
- MapPairs[K, V, H] ref
© 2016-2020, The Pony Developers
© 2014-2015, Causality Ltd.
Licensed under the BSD 2-Clause License.
https://stdlib.ponylang.io/collections-persistent-HashMap