layout.custom <- function(level, msg, …) sprintf("%s", msg)
appender.custom <- function(line) cat(line)

flog.layout(layout.custom)
flog.appender(appender.custom)
flog.info("foo")
flog.info("bar")

Cheers,
Brian

I do have a question though — when logging messages to both the console or a file, each message is appended with a new line character. Is there a way to turn this “feature” off?

Lambda.r is designed to be fully compatible with S3 data types. Regarding real world examples, I’m currently building out an event-driven analytics and forecasting platform with lambda.r in the retail banking space. I can’t share anything at the moment, but I plan to post some articles in the future. I would suggest that you look at the unit tests in the source (inst/unitTests/) for usage ideas. I’ve also updated my other packages (e.g. tawny, futile.*) to use lambda.r, so all the source code there have good examples. Feel free to ping me if you have specific questions.

Warm Regards,
Brian

your package looks very interesting. I am exploring the feasibility of functional programming with R, do you have any real world examples of using lambda.r in combination with usual data structures like data.frames or data.tables, that you can share?

- Wrap the actual values in a vars.config
- Use the {{ value }} in your sys.config or vm.args

sys.config

[
 %%  application:get_env(myapp, ampq_host) should return this
  {myapp,
	[
	  {amqp_host, {{amqp_host_variable}} }
        ]
  }
 %% SASL config
 {sasl, [
         {sasl_error_logger, {file, "log/sasl-error.log"}},
         {errlog_type, error},
         {error_logger_mf_dir, "log/sasl"},      % Log directory
         {error_logger_mf_maxbytes, 10485760},   % 10 MB max file size
         {error_logger_mf_maxfiles, 5}           % 5 files max
        ]}
].

Another recent design pattern has been using a directory inside rel with a variety of vars.

.....Makefile
.....rel/vars
......|__vars
.............|.....master_vars.config
.............|.....slave_vars.config

rel/vars/master_vars.config

{amqp_host_variable, "something"}.
{foo_bar, true}.

rel/vars/slave_vars.config

{amqp_host_variable, false}.
{start_foo_bar, false}.

Then it becomes simple to generate release for both with a Makefile as follows

master slave:
	mkdir -p dev
	(cd rel && ../rebar generate target_dir=$@ overlay_vars=vars/$@_vars.config)

See for your self as well

https://github.com/search?q=dev1+vars&type=Code&ref=searchresults

Cloning compiling some of these projects and reading their makefile (eg: make dev1 dev2 dev3) will be a great way to extend the excellent explanation this article gives.

~B