new structs to fetch, results and session

lib/feed_reader/fetch.ex

@@ -0,0 +1,21 @@
+defmodule FeedReader.Fetch do
+  @moduledoc """
+  HTTP metadata for a completed remote feed fetch.
+
+  The checksum is calculated from the decoded response body. A fetch is only
+  present on remote results and sessions; local parsing does not invent HTTP
+  metadata.
+  """
+
+  @type t :: %__MODULE__{
+          etag: String.t() | nil,
+          checksum: String.t() | nil,
+          final_url: String.t() | nil,
+          status: pos_integer() | nil
+        }
+
+  defstruct etag: nil,
+            checksum: nil,
+            final_url: nil,
+            status: nil
+end

lib/feed_reader/parse_result.ex

@@ -0,0 +1,12 @@
+defmodule FeedReader.ParseResult do
+  @moduledoc "A bounded collection of normalized data from a local source."
+
+  alias FeedReader.{Feed, Item}
+
+  @type t :: %__MODULE__{
+          feed: Feed.t(),
+          items: [Item.t()]
+        }
+
+  defstruct feed: nil, items: []
+end

lib/feed_reader/remote_result.ex

@@ -0,0 +1,18 @@
+defmodule FeedReader.RemoteResult do
+  @moduledoc """
+  A bounded collection of normalized data and metadata from a remote fetch.
+
+  The result owns no temporary file after collection completes. Its `fetch`
+  field contains the HTTP metadata needed by the caller instead.
+  """
+
+  alias FeedReader.{Feed, Fetch, Item}
+
+  @type t :: %__MODULE__{
+          feed: Feed.t(),
+          items: [Item.t()],
+          fetch: Fetch.t()
+        }
+
+  defstruct feed: nil, items: [], fetch: nil
+end

lib/feed_reader/session.ex

@@ -0,0 +1,24 @@
+defmodule FeedReader.Session do
+  @moduledoc """
+  A one-pass event stream over a feed.
+
+  Remote sessions own the temporary source used by the event stream and must
+  be closed by callers in an `after` block when enumeration is not completed.
+  `FeedReader.close/1` is idempotent. Local sessions have no HTTP metadata and
+  therefore set `fetch` to `nil`; their caller-owned source is never removed.
+  """
+
+  alias FeedReader.Fetch
+
+  @type event ::
+          {:feed, FeedReader.Feed.t()}
+          | {:item, FeedReader.Item.t()}
+          | {:error, term()}
+
+  @type t :: %__MODULE__{
+          events: Enumerable.t(),
+          fetch: Fetch.t() | nil
+        }
+
+  defstruct events: nil, fetch: nil
+end