(arrow-go) branch main updated: fix(arrow/tensor): default nil dimension names to empty strings (#999)

[zeroshade]

This is an automated email from the ASF dual-hosted git repository.

zeroshade pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/arrow-go.git


The following commit(s) were added to refs/heads/main by this push:
     new e05b7ea4 fix(arrow/tensor): default nil dimension names to empty 
strings (#999)
e05b7ea4 is described below

commit e05b7ea49e2a61bb41e97a90255e7372f64fdcd4
Author: Minh Vu <vuhoangmin...@gmail.com>
AuthorDate: Mon Jul 27 19:06:56 2026 +0200

    fix(arrow/tensor): default nil dimension names to empty strings (#999)
    
    The tensor constructors document that `nil` dimension names are treated
    as empty strings, but the shared constructor left the slice nil. That
    makes `DimName` panic on an otherwise valid tensor.
    
    This fills in one empty name per dimension and adds coverage for both
    `DimNames` and `DimName`.
    
    Tests: `go test ./arrow/tensor`
---
 arrow/tensor/tensor.go      |  4 ++++
 arrow/tensor/tensor_test.go | 18 ++++++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/arrow/tensor/tensor.go b/arrow/tensor/tensor.go
index 70bbe572..5bb88723 100644
--- a/arrow/tensor/tensor.go
+++ b/arrow/tensor/tensor.go
@@ -171,6 +171,10 @@ func New(data arrow.ArrayData, shape, strides []int64, 
names []string) Interface
 }
 
 func newTensor(dtype arrow.DataType, data arrow.ArrayData, shape, strides 
[]int64, names []string) *tensorBase {
+       if names == nil {
+               names = make([]string, len(shape))
+       }
+
        tb := tensorBase{
                dtype:   dtype,
                bw:      int64(dtype.(arrow.FixedWidthDataType).BitWidth()) / 8,
diff --git a/arrow/tensor/tensor_test.go b/arrow/tensor/tensor_test.go
index abd58ecf..42d9e98c 100644
--- a/arrow/tensor/tensor_test.go
+++ b/arrow/tensor/tensor_test.go
@@ -164,3 +164,21 @@ func TestInvalidTensor(t *testing.T) {
        })
 
 }
+
+func TestTensorWithNilDimensionNames(t *testing.T) {
+       bld := array.NewFloat64Builder(memory.DefaultAllocator)
+       defer bld.Release()
+       bld.AppendValues([]float64{1, 2}, nil)
+       arr := bld.NewFloat64Array()
+       defer arr.Release()
+
+       tsr := tensor.New(arr.Data(), []int64{2}, nil, nil)
+       defer tsr.Release()
+
+       if got, want := tsr.DimNames(), []string{""}; !reflect.DeepEqual(got, 
want) {
+               t.Fatalf("invalid dim-names: got=%v, want=%v", got, want)
+       }
+       if got := tsr.DimName(0); got != "" {
+               t.Fatalf("invalid dim-name[0]: got=%q, want empty string", got)
+       }
+}