# `Text.Language.Classifier.Fasttext.Args`
[🔗](https://github.com/kipcole9/text/blob/v0.5.0/lib/language/classifier/fasttext/args.ex#L1)

Training and model hyperparameters extracted from a fastText model file.

Mirrors the C++ `fasttext::Args` struct as written by `Args::save`. See
`docs/lid176_binary_format.md` (Section 2) for the exact byte layout.

Most fields are training-time hyperparameters that do not affect inference
but are preserved for completeness. The fields that matter at inference time
for a `lid.176`-style supervised model are `dim`, `bucket`, `minn`, and
`maxn`.

# `loss`

```elixir
@type loss() :: :hs | :ns | :softmax | :ova
```

# `model`

```elixir
@type model() :: :cbow | :sg | :sup
```

# `t`

```elixir
@type t() :: %Text.Language.Classifier.Fasttext.Args{
  bucket: non_neg_integer(),
  dim: non_neg_integer(),
  epoch: non_neg_integer(),
  loss: loss(),
  lr_update_rate: non_neg_integer(),
  maxn: non_neg_integer(),
  min_count: non_neg_integer(),
  minn: non_neg_integer(),
  model: model(),
  neg: non_neg_integer(),
  t: float(),
  word_ngrams: non_neg_integer(),
  ws: non_neg_integer()
}
```

# `decode`

```elixir
@spec decode(binary()) :: {:ok, t(), binary()} | {:error, term()}
```

Decodes the 56-byte `Args` block that follows the magic + version header.

### Arguments

* `binary` is the raw byte sequence positioned at the start of the args
  block. Must contain at least 56 bytes.

### Returns

* `{:ok, args, rest}` where `args` is a `t:t/0` struct and `rest` is the
  binary remainder positioned at the start of the dictionary block.

* `{:error, reason}` if the binary is truncated or contains an unknown
  `loss`/`model` enum value.

### Examples

    iex> args_bytes = <<
    ...>   16::little-32, 5::little-32, 1::little-32, 1000::little-32,
    ...>   5::little-32, 1::little-32, 3::little-32, 3::little-32,
    ...>   2_000_000::little-32, 2::little-32, 4::little-32, 100::little-32,
    ...>   1.0e-4::little-float-64
    ...> >>
    iex> {:ok, args, rest} = Text.Language.Classifier.Fasttext.Args.decode(args_bytes)
    iex> {args.dim, args.bucket, args.loss, args.model, rest}
    {16, 2_000_000, :softmax, :sup, ""}

---

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