[Caml-list] A question about Ocaml logging

[Chet Murthy <chetsky@gmail.com>]

All,

I hope this is the right place to ask this question.  I've been
writing a nontrivial distributed system (well, a number of them over
the last few years) and have had need of a robust and flexible logging
framework.  Specifically, I've been using "bolt" and its descendant,
"volt", which provide camlp4 syntax extensions.  These extensions make
the syntax of the logging statements significantly less verbose, and
that in itself ia a valuable thing.

With the arrival of ppx rewriters, I realize that the camlp4/camlp5
method of adding syntax to ocaml is deprecated.  So I wonder: is there
some really good logging toolkit out there, that I've overlooked.

I'm aware of a number of different packages, but only bolt/volt have
syntax extensions, and it's my belief that they're essential to making
effortless pervasive log-line instrumentation.

But perhaps I just haven't looked hard enough ....  So .... before I
go write my own, I figured I'd ask the list if there were such a
thing.

For concreteness, the basic thing I'm looking for, is a syntax
extension that somewhat resembles

  LOG "%s" appid LEVEL DEBUG ;

which expands out to code something like

begin
  if log_enabled <current-module/function-path-as-string> DEBUG then
    log (Printf.sprintf "%s" appid)
end

I hate writing "slight variations on somebody else's good idea", so
would much prefer to "improve" somebody else's library/tool, than come
up with my own.

Thanks in advance,
--chet--