SyntaxError iex: syntax error before: abci_server

[ltfschoen]

When I load the abci_server Docs in my Web Browser with:

cd deps/abci_server/ && make docs && open doc/index.html && cd ../../

The Documentation tells me I can:

To start a server on port 46658 that delegates calls to the foo module, write:

{ok, _} = abci_server:start_listener(foo, 46658).

So to try it out I add abci_server to mix.exs

defp deps do
  [
    {:abci_server, git: "https://github.com/KrzysiekJ/abci_server.git", tag: "v0.4.0"},
    # Ranch is a dependency of ABCI Server (Erlang), which is using the older 
    # version of Ranch 1.3.2, which does not support the latest GNU Make 4
    # Temporarily install Ranch 1.4.0 here until Pull Request https://github.com/KrzysiekJ/abci_server/pull/3
    # is approved and newer version of abci_server is released that uses the latest Ranch version 
    {:ranch, git: "https://github.com/ninenines/ranch.git", tag: "1.4.0"}
  ]
end

Then I install the Mix dependencies

mix deps.get

Then I run IEx within context my Elixir App (loading app and dependencies into IEx runtime)

iex -S mix

Then I create a fake module just to test it out try and Start the abci_server as instructed as follows, but it gives me error (SyntaxError) iex:2: keyword argument must be followed by space after: abci_server: when I try to run the server

iex(1)> defmodule Foo do             
...(1)>     def bar() do               
...(1)>       IO.puts("Hello, World!") 
...(1)>     end
...(1)>   end
{:module, Foo,
 <<70, 79, 82, 49, 0, 0, 4, 80, 66, 69, 65, 77, 65, 116, 85, 56, 0, 0, 0, 136,
   0, 0, 0, 15, 10, 69, 108, 105, 120, 105, 114, 46, 70, 111, 111, 8, 95, 95,
   105, 110, 102, 111, 95, 95, 9, 102, 117, ...>>, {:bar, 0}}

iex(2)> {ok, _} = abci_server:start_listener(Foo, 46658)  
** (SyntaxError) iex:2: keyword argument must be followed by space after: abci_server:

I'm still new to Elixir/Erlang, but I found this post elixir-lang/elixir-lang.github.com#980 and it indicates that I should add a space after the colon :, but then it just gives me a generic syntax error:

iex(3)> {ok, _} = abci_server: start_listener(BlockchainTendermint, 46658).
** (SyntaxError) iex:3: syntax error before: abci_server

So I did more research and I found this link which says I can use Erlang packages that are installed as dependencies from an Elixir project’s Mix file https://elixirschool.com/en/lessons/advanced/erlang/#erlang-packages.
So according to their guide, if I include an Erlang Library in mix.exs as {:abci_server, git: "https://github.com/KrzysiekJ/abci_server.git", tag: "v0.4.0"},, then I should be able to check it has loaded and use it’s associated functions when I run IEx with iex(3)> :abci_server.__info__(:functions), but doing so just returns ** (UndefinedFunctionError) function :abci_server.__info__/1 is undefined or private

[ltfschoen]

I finally overcame the problem after posting the question in the Elixir Slack group https://elixir-lang.slack.com/archives/C03EPRA3B/p1517016786000068.

First with some help I was able to show information about the :abci_server to confirm it had been successfully imported. I was told that __info__/1 is an Elixir thing the compiler adds, and that I should use module_info/1 which is the Erlang equivalent - https://elixir-lang.slack.com/archives/C03EPRA3B/p1517018221000028

iex> :abci_server.module_info  
[
  module: :abci_server,
  exports: [
    start_link: 4,
    start_listener: 2,
    child_spec: 2,
    stop_listener: 1,
    init: 1,
    handle_call: 3,
    handle_cast: 2,
    handle_info: 2,
    terminate: 2,
    code_change: 3,
    module_info: 0,
    module_info: 1
  ],
  attributes: [
    vsn: [86973587470476204871336807197797490126],
    behaviour: [:gen_server],
    behaviour: [:ranch_protocol]
  ],
  compile: [
    options: [
      :debug_info,
      {:i,
      '/Users/Ls/code/blockchain/tendermint-elixir/blockchain_tendermint/deps/abci_server/include'},
      :warn_obsolete_guard,
      :warn_shadow_vars,
      :warn_export_vars
    ],
    version: '7.1.4',
    source: '/Users/Ls/code/blockchain/tendermint-elixir/blockchain_tendermint/deps/abci_server/src/abci_server.erl'
  ],
  native: false,
  md5: <<65, 110, 128, 239, 19, 146, 215, 5, 182, 173, 33, 116, 159, 63, 157,
    206>>
]

I then created a fake Foo function:

iex>  defmodule Foo do             
        def bar() do               
          IO.puts("Hello, World!") 
        end
      end

And then lastly I called the start_listener function, using syntax recommended in the Slack channel:

iex> {ok, _} = :abci_server.start_listener(Foo, 46658)
{:ok, #PID<0.181.0>}
iex> ok = :abci_server.stop_listener(Foo)             
:ok

I've updated this Pull Request #3 with proposed updates to the Readme, since the Generated Docs may not be clear enough for beginners

[KrzysiekJ]

The line

{ok, _} = abci_server:start_listener(foo, 46658).

is intended to be used in Erlang shell, hence it uses the Erlang syntax. As noted, syntax for Elixir shell will be different.