[I] There is an error in the usage example of the Compute Function on the official website? [arrow]

[via GitHub]

caiwanli opened a new issue, #38847:
URL: https://github.com/apache/arrow/issues/38847

   ### Describe the usage question you have. Please include as many useful 
details as  possible.
   
   
   I use Compute Function according to the example on the official website, and 
can compile successfully, but in the execution is an error: Key error: No 
function registered with name: sum
   Here's my code:
   
   #include <iostream>
   #include <arrow/api.h>
   #include <arrow/compute/api.h>
   
   using namespace std;
   
   arrow::Status RunMain() {
       // Create a couple 32-bit integer arrays.
       arrow::Int32Builder int32builder;
       int32_t some_nums_raw[5] = {34, 624, 2223, 5654, 4356};
       ARROW_RETURN_NOT_OK(int32builder.AppendValues(some_nums_raw, 5));
       std::shared_ptr<arrow::Array> some_nums;
       ARROW_ASSIGN_OR_RAISE(some_nums, int32builder.Finish());
   
       int32_t more_nums_raw[5] = {75342, 23, 64, 17, 736};
       ARROW_RETURN_NOT_OK(int32builder.AppendValues(more_nums_raw, 5));
       std::shared_ptr<arrow::Array> more_nums;
       ARROW_ASSIGN_OR_RAISE(more_nums, int32builder.Finish());
   
       // Make a table out of our pair of arrays.
       std::shared_ptr<arrow::Field> field_a, field_b;
       std::shared_ptr<arrow::Schema> schema;
   
       field_a = arrow::field("A", arrow::int32());
       field_b = arrow::field("B", arrow::int32());
   
       schema = arrow::schema({field_a, field_b});
   
       std::shared_ptr<arrow::Table> table;
       table = arrow::Table::Make(schema, {some_nums, more_nums}, 5);
       
       arrow::Datum tmp;
       ARROW_ASSIGN_OR_RAISE(tmp, 
arrow::compute::Sum({table->GetColumnByName("A")}));
       // Get the kind of Datum and what it holds -- this is a Scalar, with 
int64.
       std::cout << "Datum kind: " << tmp.ToString() << " content type: " << 
tmp.type()->ToString() << std::endl;
       std::cout << tmp.scalar_as<arrow::Int64Scalar>().value << std::endl;
   
       return arrow::Status::OK();
   }
   
   int main() {
      arrow::Status st = RunMain();
       if (!st.ok()) {
           std::cerr << st << std::endl;
           return 1;
       }
       return 0;
   }
   
   
   ### Component(s)
   
   C++


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