Function PromoteExecSpanScalars

cpp/src/arrow/compute/exec.cc:319–330

namespace {

void PromoteExecSpanScalars(ExecSpan* span) {
  // In the "all scalar" case, we "promote" the scalars to ArraySpans of
  // length 1, since the kernel implementations do not handle the all
  // scalar case
  for (int i = 0; i < span->num_values(); ++i) {
    ExecValue* value = &span->values[i];
    if (value->is_scalar()) {
      value->array.FillFromScalar(*value->scalar);
      value->scalar = nullptr;
    }
  }
}

bool CheckIfAllScalar(const ExecBatch& batch) {
  for (const Datum& value : batch.values) {