Jörn Horstmann created ARROW-8383:
-------------------------------------
Summary: [RUST] Easier random access to DictionaryArray keys and
values
Key: ARROW-8383
URL: https://issues.apache.org/jira/browse/ARROW-8383
Project: Apache Arrow
Issue Type: Improvement
Components: Rust
Reporter: Jörn Horstmann
Currently it's not that clear how to acces DictionaryArray keys and values
using random indices.
The `DictionaryArray::keys` method exposes an Iterator with an `nth` method,
but this requires a mut reference and feels a little bit out of place compared
to other methods of accessing arrow data.
Another alternative seems to be to use the `From<ArrayDataRef> for
PrimitiveArray<T>` conversion like so `let keys : Int16Array =
dictionary_array.data().into()`. This seems to work fine but is not easily
discoverable and also needs to be done outside of any loops for performance
reasons.
I'd like methods on `DictionaryArray` to directly get the key at some index
```
pub fn key(&self, i: usize) -> &K
```
Ideally I'd also like an easier way to directly access values at some index, at
least when those are primitive or string types.
```
pub fn value(&self, i: usize) -> &T
```
I'm not sure how or if that would be possible to implement with rust generics.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
