These functions are equivalent to base functions base::stop(),
base::warning() and base::message(), but the type argument
makes it easy to create subclassed conditions. They also don't
include call information by default. This saves you from typing
call. = FALSE to make error messages cleaner within package
functions.
abort(msg, type = NULL, call = FALSE)warn(msg, type = NULL, call = FALSE)
inform(msg, type = NULL, call = FALSE)
A message to display.
Subclass of the condition to signal.
Whether to display the call.
Like stop() and cnd_abort(), abort() signals a critical
condition and interrupts execution by jumping to top level (see
rst_abort()). Only a handler of the relevant type can prevent
this jump by making another jump to a different target on the stack
(see with_handlers()).
warn() and inform() both have the side effect of displaying a
message. These messages will not be displayed if a handler
transfers control. Transfer can be achieved by establishing an
exiting handler that transfers control to with_handlers()). In
this case, the current function stops and execution resumes at the
point where handlers were established.
Since it is often desirable to continue normally after a message or
warning, both warn() and inform() (and their base R equivalent)
establish a muffle restart where handlers can jump to prevent the
message from being displayed. Execution resumes normally after
that. See rst_muffle() to jump to a muffling restart, and the
muffle argument of inplace() for creating a muffling handler.