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https://issues.apache.org/jira/browse/ARROW-5745?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16874497#comment-16874497
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Benjamin Kietzman commented on ARROW-5745:
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Using "values" at all is very confusing since we already use that as the noun
which indicates what occupies an array slot (see
[Layout.rst|https://github.com/apache/arrow/blob/master/docs/source/format/Layout.rst#definitions--terminology]).
It would really
help in explaining List if we used another word here to indicate what occupies
slots in List's child array; "items" or "entries" would be equally expressive
and are less heavily overloaded. As it is, "value" is used for both purposes,
[*in the same sentence* of
Layout.rst.|https://github.com/apache/arrow/blob/master/docs/source/format/Layout.rst#list-type]
Using "values" in the context of Map is probably unavoidable due to the very
strong convention of naming elements of the range and domain of a mapping its
"keys" and "values". (A related Python-specific convention is to name the
sequence
of key-value pairs "items", as in `dict`.)
However by renaming `ListArray::values` at least we can avoid collision between
the
expectation that `map_array.values()` will yield the array of all mapped values
and the reality that it will return the array of key-value pairs, and without
adding a prefix.
> [C++] properties of Map(Array|Type) are confusingly named
> ---------------------------------------------------------
>
> Key: ARROW-5745
> URL: https://issues.apache.org/jira/browse/ARROW-5745
> Project: Apache Arrow
> Issue Type: New Feature
> Components: C++
> Reporter: Benjamin Kietzman
> Assignee: Benjamin Kietzman
> Priority: Major
>
> In the context of ListArrays, "values" indicates the elements in a slot of
> the ListArray. Since MapArray isa ListArray, "values" indicates the same
> thing and the elements are key-item pairs. This naming scheme is not
> idiomatic; these *should* be called key-value pairs but that would require
> propagating the renaming down to ListArray.
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