[C++] RunEndEncodedBuilder does not merge consecutive NaN values

[andishgar]

Describe the bug, including details regarding any error messages, version, and platform.

The following code:

auto ree_type = run_end_encoded(int32(), float32());
auto int32_builder = std::make_shared<Int32Builder>(pool_);
auto float_builder = std::make_shared<FloatBuilder>(pool_);
RunEndEncodedBuilder builder(pool_, int32_builder, float_builder, ree_type);
ASSERT_OK(builder.AppendScalar(**MakeScalar(float32(), std::nanf("0")), 3));
ASSERT_OK(builder.AppendScalar(**MakeScalar(float32(), std::nanf("0")), 3));
ASSERT_OK_AND_ASSIGN(auto array, builder.Finish());
ARROW_LOGGER_INFO("", array->ToString());

produces the following output. This indicates that consecutive NaN values are treated as distinct values instead of being merged into a single run:

-- run_ends:
  [
    3,
    6
  ]
-- values:
  [
    nan,
    nan
  ]

Component(s)

C++

[snoopuppy582]

take

[andishgar]

@snoopuppy582, thanks for your interest and contribution. I was planning to work on this issue myself, so could you please consider picking up another issue instead? I appreciate your help.

[snoopuppy582]

Understood, thanks for letting me know. I'll step back and pick up another issue. I don't have permission to remove my assignment, so please feel free to unassign me.