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new a23c2c7f52 GH-38211: [MATLAB] Add support for creating an empty
`arrow.tabular.RecordBatch` by calling `arrow.recordBatch` with no input
arguments (#47060)
a23c2c7f52 is described below
commit a23c2c7f5268c516a48b30940ae77c4137b4b495
Author: Sarah Gilmore <[email protected]>
AuthorDate: Thu Jul 10 15:00:43 2025 -0400
GH-38211: [MATLAB] Add support for creating an empty
`arrow.tabular.RecordBatch` by calling `arrow.recordBatch` with no input
arguments (#47060)
### Rationale for this change
Currently, the `arrow.table` construction function will return an empty
`arrow.tabular.Table` if no input arguments are passed to the function.
However, `arrow.recordBatch` throws an error in this case. We should consider
making `arrow.recordBatch` behave consistently with `arrow.table` in this case.
This should be relatively straightforward to implement. We can just set the
input argument `T` to default to `table.empty(0,0)` in the `arguments` block of
the `recordBatch` function, in the same way that `arrow.table` does:
https://github.com/apache/arrow/blob/73454b7040fbea3a187c1bfabd7ea02d46ca3c41/matlab/src/matlab/%2Barrow/table.m#L21
### What changes are included in this PR?
Updated the `arrow.recordBatch` function to return an
`arrow.tabular.RecordBatch` instance with zero columns and zero rows if called
with zero input arguments. Before this change, the `arrow.recordBatch` function
would throw an error if called with zero input arguments.
**Example Usage:**
```matlab
>> rb = arrow.recordBatch()
rb =
Arrow RecordBatch with 0 rows and 0 columns
```
### Are these changes tested?
Yes. Added a new test case to `tRecordBatch` called
`ConvenienceConstructorZeroArguments`.
### Are there any user-facing changes?
Yes. Users can now call `arrow.recordBatch` with zero input arguments.
* GitHub Issue: #38211
Authored-by: Sarah Gilmore <[email protected]>
Signed-off-by: Sarah Gilmore <[email protected]>
---
matlab/src/matlab/+arrow/recordBatch.m | 2 +-
matlab/test/arrow/tabular/tRecordBatch.m | 11 +++++++++++
2 files changed, 12 insertions(+), 1 deletion(-)
diff --git a/matlab/src/matlab/+arrow/recordBatch.m
b/matlab/src/matlab/+arrow/recordBatch.m
index dd4a042b9d..c86c5b79e1 100644
--- a/matlab/src/matlab/+arrow/recordBatch.m
+++ b/matlab/src/matlab/+arrow/recordBatch.m
@@ -16,7 +16,7 @@
% permissions and limitations under the License.
function rb = recordBatch(T)
arguments
- T table
+ T table = table.empty(0, 0)
end
arrowArrays = arrow.tabular.internal.decompose(T);
diff --git a/matlab/test/arrow/tabular/tRecordBatch.m
b/matlab/test/arrow/tabular/tRecordBatch.m
index 94166f6f33..f2f0fb4d87 100644
--- a/matlab/test/arrow/tabular/tRecordBatch.m
+++ b/matlab/test/arrow/tabular/tRecordBatch.m
@@ -25,6 +25,17 @@ classdef tRecordBatch < matlab.unittest.TestCase
tc.verifyEqual(className, "arrow.tabular.RecordBatch");
end
+ function ConvenienceConstructorZeroArguments(tc)
+ % Verify the arrow.recordBatch function returns an
+ % arrow.tabular.RecordBatch instance with zero rows and zero
+ % columns if called with zero input arguments.
+ recordBatch = arrow.recordBatch();
+ className = string(class(recordBatch));
+ tc.verifyEqual(className, "arrow.tabular.RecordBatch");
+ tc.verifyEqual(recordBatch.NumRows, int64(0));
+ tc.verifyEqual(recordBatch.NumColumns, int32(0));
+ end
+
function SupportedTypes(tc)
% Create a table all supported MATLAB types.
import arrow.internal.test.tabular.createTableWithSupportedTypes
