which OO programming style in R will result readable to a Python programmer?

Question

I'm author of the logging package on CRAN, I don't see myself as an R programmer, so I tried to make it as code-compatible with the Python standard logging package as I could, but now I have a question. and I hope it will give me the chance to learn some more R!

it's about hierarchical loggers. in Python I would create a logger and send it logging records:

l = logging.getLogger("some.lower.name")
l.debug("test")
l.info("some")
l.warn("say no")

In my R package instead you do not create a logger to which you send messages, you invoke a function where one of the arguments is the name of the logger. something like

logdebug("test", logger="some.lower.name")
loginfo("some", logger="some.lower.name")
logwarn("say no", logger="some.lower.name")

the problem is that you have to repeat the name of the logger each time you want to send it a logging message. I was thinking, I might create a partially applied function object and invoke that instead, something like

logdebug <- curry(logging::logdebug, logger="some.lower.logger")

but then I need doing so for all debugging functions...

how would you R users approach this?

Answer 1

Sounds like a job for a reference class ?setRefClass, ?ReferenceClasses

Logger <- setRefClass("Logger",
                  fields=list(name = "character"),
                  methods=list(
                    log = function(level, ...) 
                          { levellog(level, ..., logger=name) },
                    debug = function(...) { log("DEBUG", ...) },
                    info = function(...) { log("INFO", ...) },
                    warn = function(...) { log("WARN", ...) },
                    error = function(...) { log("ERROR", ...) }
                    ))

and then

> basicConfig()
> l <- Logger$new(name="hierarchic.logger.name")
> l$debug("oops")
> l$info("oops")
2011-02-11 11:54:05 NumericLevel(INFO):hierarchic.logger.name:oops
> l$warn("oops")
2011-02-11 11:54:11 NumericLevel(WARN):hierarchic.logger.name:oops
>