# `SnakeBridge.Types.Decoder`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/types/decoder.ex#L1)

Decodes JSON-compatible data from Python into Elixir data structures.

Handles lossless decoding of tagged representations produced by the Python
side or by `SnakeBridge.Types.Encoder`. Recognizes special `__type__` markers
to reconstruct Elixir-specific types. Atom decoding is allowlist-based
(configure via `:snakebridge, :atom_allowlist`).

## Supported Tagged Types

- `{"__type__": "atom", "value": "ok"}` → `:ok` (allowlisted only)
- `{"__type__": "tuple", "elements": [...]}` → Elixir tuple
- `{"__type__": "set", "elements": [...]}` → MapSet
- `{"__type__": "frozenset", "elements": [...]}` → MapSet
- `{"__type__": "bytes", "data": "<base64>"}` → binary
- `{"__type__": "datetime", "value": "<iso8601>"}` → DateTime
- `{"__type__": "date", "value": "<iso8601>"}` → Date
- `{"__type__": "time", "value": "<iso8601>"}` → Time
- `{"__type__": "special_float", "value": "infinity"}` → `:infinity`
- `{"__type__": "special_float", "value": "neg_infinity"}` → `:neg_infinity`
- `{"__type__": "special_float", "value": "nan"}` → `:nan`
- `{"__type__": "ref", ...}` → `SnakeBridge.Ref`
- `{"__type__": "stream_ref", ...}` → `SnakeBridge.StreamRef`

## Direct JSON Types

- `null` → `nil`
- Booleans → `true`/`false`
- Numbers → integers or floats
- Strings → strings
- Arrays → lists (recursively decoded)
- Objects → maps with string keys (recursively decoded)

## Examples

    iex> SnakeBridge.Types.Decoder.decode(%{"__type__" => "tuple", "elements" => [1, 2, 3]})
    {1, 2, 3}

    iex> SnakeBridge.Types.Decoder.decode(%{"__type__" => "set", "elements" => [1, 2, 3]})
    #MapSet<[1, 2, 3]>

    iex> SnakeBridge.Types.Decoder.decode(%{"a" => 1, "b" => 2})
    %{"a" => 1, "b" => 2}

# `decode`
[🔗](https://github.com/nshkrdotcom/snakebridge/blob/v0.14.0/lib/snakebridge/types/decoder.ex#L69)

```elixir
@spec decode(term()) :: term()
```

Decodes a JSON-compatible value into an Elixir data structure.

Recognizes and handles tagged types from the Python encoder.

## Examples

    iex> decode(42)
    42

    iex> decode([1, 2, 3])
    [1, 2, 3]

    iex> decode(%{
    ...>   "__type__" => "tuple",
    ...>   "elements" => [%{"__type__" => "atom", "value" => "ok"}, "result"]
    ...> })
    {:ok, "result"}

---

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