improvement: make tsvector type selectable

lib/types/tsvector.ex

@@ -1,12 +1,63 @@
 defmodule AshPostgres.Tsvector do
   @moduledoc """
-  A thin wrapper around `:string` for working with tsvector types in calculations.
+  A type for representing postgres' tsvectors.
 
-  A calculation of this type cannot be selected, but may be used in calculations.
+  Values will be a list of `Postgrex.Lexeme`
   """
 
   use Ash.Type.NewType, subtype_of: :term
 
   @impl true
   def storage_type(_), do: :tsvector
+
+  @impl true
+  def cast_input(nil, _) do
+    {:ok, nil}
+  end
+
+  def cast_input(values, _) when is_list(values) do
+    if Enum.all?(values, &is_struct(&1, Postgrex.Lexeme)) do
+      {:ok, values}
+    else
+      :error
+    end
+  end
+
+  def cast_input(_, _) do
+    :error
+  end
+
+  @impl true
+  def dump_to_native(nil, _) do
+    {:ok, nil}
+  end
+
+  def dump_to_native(values, _) when is_list(values) do
+    if Enum.all?(values, &is_struct(&1, Postgrex.Lexeme)) do
+      {:ok, values}
+    else
+      :error
+    end
+  end
+
+  def dump_to_native(_, _) do
+    :error
+  end
+
+  @impl true
+  def cast_stored(nil, _) do
+    {:ok, nil}
+  end
+
+  def cast_stored(values, _) when is_list(values) do
+    if Enum.all?(values, &is_struct(&1, Postgrex.Lexeme)) do
+      {:ok, values}
+    else
+      :error
+    end
+  end
+
+  def cast_stored(_, _) do
+    :error
+  end
 end