[jira] [Created] (ARROW-13136) [C++] Add a "coalesce" variadic scalar kernel

["Ian Cook (Jira)" <ji...@apache.org>]

Ian Cook created ARROW-13136:
--------------------------------

             Summary: [C++] Add a "coalesce" variadic scalar kernel
                 Key: ARROW-13136
                 URL: https://issues.apache.org/jira/browse/ARROW-13136
             Project: Apache Arrow
          Issue Type: Improvement
          Components: C++
            Reporter: Ian Cook


Add a variadic scalar compute kernel that works like the SQL {{coalesce}} function. It should take arbitrarily many inputs of the same or compatible types and process them row-wise, returning the first non-null value in each row, or returning {{null}} if there are no non-null values in the row. 

For example, in the case of 3 integer-type input arrays, this would take inputs:
{code:java}
Array<int32>         Array<int32>         Array<int32>
[                    [                    [
  null,                2,                   3,
  4,                   null,                6,
  null,                null,                9,
  null                 null                 null
]                    ]                    ]
{code}
and return output:
{code:java}
Array<int32>
[ 
  2,
  4,
  9,
  null
] 
{code}
This should also accept scalar values and recycle their values.



--
This message was sent by Atlassian Jira
(v8.3.4#803005)