Idl parser

[seriyps]

Implementation of idl parser. Fixes #68.

Usage Examples

// file: my_service.avdl

@namespace("com.example")
protocol MyService {
  enum Status { OK, ERROR }

  record Response {
    string id;
    Status status;
    union { null, string } message = null;
  }
}

Load a schema file and encode/decode

Store = avro_schema_store:new([], ["my_service.avdl"]),
LookupFun = avro_schema_store:to_lookup_fun(Store),
Encoder = avro:make_encoder(LookupFun, []),
Decoder = avro:make_decoder(LookupFun, []),

Record = [{"id", <<"req-1">>}, {"status", <<"OK">>}],
Bin = iolist_to_binary(Encoder("com.example.Response", Record)),
Record = Decoder("com.example.Response", Bin).

Convert .avdl to an AVPR map (JSON protocol representation)

{ok, Bin} = file:read_file("my_service.avdl"),
Avpr = avro_idl:str_to_avpr(
         binary_to_list(Bin),
         filename:dirname("my_service.avdl")),
%% Avpr is a map: #{<<"protocol">> => ..., <<"types">> => [...], <<"messages">> => ...}

In-memory schemas (useful for tests or embedded schemas)

Files = #{
    {"schemas", "common.avdl"} =>
        <<"protocol Common { record Address { string city; } }">>,
    {"schemas", "order.avdl"} =>
        <<"protocol Orders {  import idl \"common.avdl\"; record Order { string id; int amount; } }">>
},
ReadFun = fun(Cwd, Path) ->
    case maps:find({Cwd, Path}, Files) of
        {ok, Bin} -> {ok, Bin};
        error     -> {error, enoent}
    end
end,
{ok, Src} = maps:find({"schemas", "order.avdl"}, Files),
Schema = avro_idl:decode_schema(
           binary_to_list(Src), "schemas",
           [{read_fun, ReadFun}]).

[coveralls]

Pull Request Test Coverage Report for Build 599

• 75 of 77 (97.4%) changed or added relevant lines in 2 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-29.7%) to 70.257%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/avro_idl.erl	70	72	97.22%

Totals
Change from base Build 591:	-29.7%
Covered Lines:	2870
Relevant Lines:	4085

---

💛 - Coveralls

[CLAassistant]

All committers have signed the CLA.

[seriyps]

@zmstone this is now ready. It took me some time to finalize it 😄

[mikpe]

With the caveat wrt the record name.