add docs for StreamEncoder

Author: nrednav

lib/msgpack/stream_encoder.ex

@@ -1,6 +1,61 @@
 defmodule Msgpack.StreamEncoder do
+  @moduledoc """
+  Lazily encodes a stream of Elixir terms into a stream of MessagePack binaries.
+
+  This module is the counterpart to `Msgpack.StreamDecoder`. It processes an
+  enumerable item by item, making it memory-efficient for encoding large
+  collections or infinite streams without loading the entire dataset into
+  memory.
+
+  Each item in the output stream is a result tuple, either `{:ok, binary}` for
+  a successful encoding or `{:error, reason}` if an individual term could
+  not be encoded.
+  """
+
   @doc """
-  Encodes a stream of Elixir terms into a stream of MessagePack binaries.
+  Lazily encodes an enumerable of Elixir terms into a stream of result tuples.
+
+  ## Parameters
+
+    * `enumerable`: An `Enumerable` that yields Elixir terms to be encoded.
+    * `opts`: A keyword list of options passed to the underlying encoder for each term.
+
+  ## Return Value
+
+  Returns a lazy `Stream` that emits result tuples. For each term in the
+  input enumerable, the stream will contain either:
+    * `{:ok, binary}` - On successful encoding.
+    * `{:error, reason}` - If the term cannot be encoded.
+
+  ## Options
+
+  This function accepts the same options as `Msgpack.encode/2`. See the
+  documentation for `Msgpack.encode/2` for a full list.
+
+  ## Examples
+
+  ### Standard Usage
+
+  ```elixir
+  iex> terms = [1, "elixir"]
+  iex> Msgpack.StreamEncoder.encode(terms) |> Enum.to_list()
+  [
+    {:ok, <<1>>},
+    {:ok, <<166, 101, 108, 105, 120, 105, 114>>}
+  ]
+  ```
+
+  ### Handling Unencodable Terms
+
+  ```elixir
+  iex> terms = [1, :elixir, 4]
+  iex> Msgpack.StreamEncoder.encode(terms, atoms: :error) |> Enum.to_list()
+  [
+    {:ok, <<1>>},
+    {:error, {:unsupported_atom, :elixir}},
+    {:ok, <<4>>}
+  ]
+  ```
   """
   def encode(enumerable, opts \\ []) do
     Stream.map(enumerable, &Msgpack.encode(&1, opts))