# `Arrow`

Pure-Elixir implementation of the [Apache Arrow](https://arrow.apache.org/)
columnar format.

This top-level module is intentionally thin. The library's surface area lives
under:

- `Arrow.Schema`, `Arrow.Field`, `Arrow.Type.*` — schema description.
- `Arrow.Array.*` — per-type columnar arrays.
- `Arrow.RecordBatch` — schema + columns batch.
- `Arrow.Buffer` — encoder/decoder between in-memory arrays and the on-wire
  buffer layout.
- `Arrow.Json` — Arrow integration test JSON form, used for
  cross-implementation conformance.

## Example

Encode a record batch to the IPC streaming format and decode it back:

    iex> schema = %Arrow.Schema{
    ...>   fields: [%Arrow.Field{name: "id", type: %Arrow.Type.Int{bit_width: 32, signed: true}}]
    ...> }
    iex> batch = %Arrow.RecordBatch{
    ...>   schema: schema,
    ...>   length: 3,
    ...>   columns: [
    ...>     %Arrow.Array.Int32{
    ...>       length: 3,
    ...>       null_count: 0,
    ...>       values: Arrow.Buffer.pack_primitive([1, 2, 3], :int32)
    ...>     }
    ...>   ]
    ...> }
    iex> stream = Arrow.Ipc.Stream.encode(schema, [batch])
    iex> {:ok, %{batches: [decoded]}} = Arrow.Ipc.Stream.decode(stream)
    iex> Arrow.Logical.to_list(hd(decoded.columns))
    [1, 2, 3]

---

*Consult [api-reference.md](api-reference.md) for complete listing*