how to ignore future browser calls

Question

When debugging, it is often useful to insert a browser() call in the code. If everything is fine and I would like to finish the function I can use c but if the browser is in a loop what would be the appropriate way to ignore this new calls?

I looked into browser help but didn't find something. I'm currently doing:

browser <- function(...){NULL}

Replacing the original browser function but it's not quite satifying.

Answer 1

You can wrap browser in its own call and make it conditional:

breakpoint = function ()
    if (! exists('.break_disabled', parent.env(environment())))
        browser(skipCalls = 1L)

The skipCalls option is used because the browser call is nested inside a function rather than being called directly from where you want to break.

Now you just need to supply two functions to toggle breakpoints:

disable_break = function ()
    assign('.break_disabled', TRUE, parent.env(environment()))

enable_break = function ()
    if (exists('.break_disabled', parent.env(environment())))
        rm(.break_disabled, envir = parent.env(environment()))

It’s worth noting that just pasting the above functions into a script or an R session will pollute the global namespace with a hidden object. Normally I’d therefore define these functions in their own environment. However, for debugging purposes this should be fine.