messages sent at a level less than the current level will not be output.
returns the last level passed to set_level, which will be the log level
checked as a threshold against the level of the next message sent.
changes the output type of the log, which can be useful when daemonizing.
The new output type will be applied to all subsequent messages.
if `Raise is given then background errors raised by logging will be raised to the
monitor that was in scope when create was called. Errors can be redirected anywhere
by providing `Call f.
any call that writes to a log after close is called will raise.
returns true if close has been called
returns a Deferred.t that is fulfilled when the last message delivered to t before the
call to flushed is out the door.
informs the current Outputs to rotate if possible
create a new log. See set_level, set_on_error and set_output for
raw printf like logging for raw (no level) messages. Raw messages are still
output with a timestamp.
debug printf like logging at the `Debug log level
info printf like logging at the `Info log level
error printf like logging at the `Error log level
printf generalized printf style logging
sexp log sexps directly
string logging of string values
message log a preexisting message
would_log returns true if a message at the given log level would be logged if sent