add extype field extension

Author: lizziepaquette

lib/brex_elixirpb.pb.ex

@@ -0,0 +1,20 @@
+defmodule Brex.Elixirpb.FieldOptions do
+  @moduledoc false
+  use Protobuf, syntax: :proto2
+
+  @type t :: %__MODULE__{
+          extype: String.t()
+        }
+  defstruct [:extype]
+
+  field :extype, 1, optional: true, type: :string
+end
+
+defmodule Brex.Elixirpb.PbExtension do
+  @moduledoc false
+  use Protobuf, syntax: :proto2
+
+  extend Google.Protobuf.FieldOptions, :field, 65007,
+    optional: true,
+    type: Brex.Elixirpb.FieldOptions
+end

src/brex_elixirpb.proto

@@ -0,0 +1,22 @@
+syntax = "proto2";
+
+package brex.elixirpb;
+import "google/protobuf/descriptor.proto";
+
+// Defines an extension to specify the elixir type generated for the given field.
+
+// For example,
+// google.protobuf.StringValue my_string = 1 [(brex.elixirpb.field).extype="String.t"];
+
+// To compile
+//protoc --plugin=/Users/lizard/Projects/Work/git/brex/protobuf-elixir/protoc-gen-elixir --proto_path=lib --elixir_out=lib brex_elixirpb.proto
+
+message FieldOptions {
+  // Specify an elixir type to generate for this field. This will override usual type.
+  optional string extype = 1;
+}
+
+extend google.protobuf.FieldOptions {
+  // Note: number to change
+  optional FieldOptions field = 65007;
+}