Interrupt the execution of an expression and allow the
inspection of the environment where browser was called from.
browser(text = "", condition = NULL, expr = TRUE, skipCalls =
0L) - a text string that can be retrieved once the browser is
invoked. - a condition that can be retrieved once the browser is
invoked. - An expression, which if it evaluates to TRUEthe
debugger will invoked, otherwise control is returned directly. -
how many previous calls to skip when reporting the calling
context. A call to browser can be included in the body of a
function. When reached, this causes a pause in the execution of
the current expression and allows access to the R interpreter.
The purpose of the condition arguments are to allow helper
programs (e.g. external debuggers) to insert specific values
here, so that the specific call to browser (perhaps its location
in a source file) can be identified and special processing can
be achieved. The values can be retrieved by calling The purpose
of the expr argument is to allow for