lverbose: Logging Feature

Description

lverbose returns/sets the current verbosity level.

lverbose(val, global = FALSE)
lsilent()
is.verbose()
lmessage(level, ..., appendLF = TRUE, sep = "", force = FALSE)
vmessage(...)
log_append(...)

the old verbose level

val: logical/numeric value that sets the verbosity level.
global: logical that indicates if the verbose level of all log handlers should be set to val.
level: verbosity level threshold (numeric value) above which the message should be printed out. This threshold is compared with the current verbosity level as returned by lverbose.
...: parts of a character message that are concatenated and passed to the current logger's write function.
appendLF: logical indicating if an endline character should be appended at the end of the message.
sep: separation character, used when concatenating all arguments in ....
force: logical that indicates if one should output messages or return a non null logger, even if the verbose mode is not high enough.

lsilent(): tells if all verbose messages are silenced.
is.verbose(): tells if verbosity is on, i.e. at level greater than 0.
lmessage(): prints out a message (on sdtout) if the verbosity level is greater than a given value.
vmessage(): prints out a log message (at level 1) using the current logger, typically on stdout. It is a shortcut for lmessage(1L, ...).
log_append(): directly appends some message to the current log line.