R devel - Feb 2020 - R --interactive -e 'browser()'

I would like to have a mode where I can run some R code in an executable script,
like with Rscript, but interactively, so that e.g. 'browser()' works.

 From the manual page it looks like this should work:

     R --interactive -e 'source("script.R")'

or we could shorten it to:

     R --interactive -e 'browser()'

However, it seems that --interactive causes -e to be ignored.

And if I leave out --interactive, then R quits before the browser() function
exits.

 From an engineering standpoint it doesn't seem like it should be very
difficult to tell the interactive REPL to pretend that a certain command was
entered before everything else. Also, it would be useful to me to be able to
debug R scripts using standard features like 'browser()'. Should I
submit a feature request on Bugzilla, or maybe someone can advise me how to
proceed?

Thanks,

Frederick

Here's what I would expect:

In interactive mode, input is taken from the user (i.e. command line).
In non-interactive mode, input is taken from a text file (or equivalent).

What you're trying to do is run R in *non*-interactive mode, and call
the browser function.
This requires input to come from the user (i.e. command line) and from
a text file (or equivalent), at essentially the same time.

While doing fantasmoswankyblastik things with I/O is a lot of fun.
I don't think it's R's job to do that.


On Fri, Feb 21, 2020 at 6:25 PM <frederik at ofb.net>
wrote:
>
> I would like to have a mode where I can run some R code in an executable
script, like with Rscript, but interactively, so that e.g. 'browser()'
works.
>
>  From the manual page it looks like this should work:
>
>      R --interactive -e 'source("script.R")'
>
> or we could shorten it to:
>
>      R --interactive -e 'browser()'
>
> However, it seems that --interactive causes -e to be ignored.
>
> And if I leave out --interactive, then R quits before the browser()
function exits.
>
>  From an engineering standpoint it doesn't seem like it should be very
difficult to tell the interactive REPL to pretend that a certain command was
entered before everything else. Also, it would be useful to me to be able to
debug R scripts using standard features like 'browser()'. Should I
submit a feature request on Bugzilla, or maybe someone can advise me how to
proceed?
>
> Thanks,
>
> Frederick
>
> ______________________________________________
> R-devel at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-devel

I should add:

In theory, R could emulate the behavior of a compiled programming language.
(In which case, R could read input from the user, or use debugging
tools, when told to).
However, I can't see R-core supporting this approach in the foreseeable
future.

A related topic is running R inside Java and C++ programs.
Something R-core is *un*enthusiastic about...???

I note that a number of people have requested the ability to run R
scripts like executable files (easily), or to run scripts with partial
interactivity.

It would be possible to create a special-purpose pty-based (or
pty-like) application specifically to run R, which could allow the
user to emulate the behavior of a compiled language (and do a few
other things), but I'm wondering if it's ethical to publish it...???


On Sun, Feb 23, 2020 at 10:21 AM Abby Spurdle <spurdle.a at gmail.com>
wrote:
>
> Here's what I would expect:
>
> In interactive mode, input is taken from the user (i.e. command line).
> In non-interactive mode, input is taken from a text file (or equivalent).
>
> What you're trying to do is run R in *non*-interactive mode, and call
> the browser function.
> This requires input to come from the user (i.e. command line) and from
> a text file (or equivalent), at essentially the same time.
>
> While doing fantasmoswankyblastik things with I/O is a lot of fun.
> I don't think it's R's job to do that.
>
>
> On Fri, Feb 21, 2020 at 6:25 PM <frederik at ofb.net> wrote:
> >
> > I would like to have a mode where I can run some R code in an
executable script, like with Rscript, but interactively, so that e.g.
'browser()' works.
> >
> >  From the manual page it looks like this should work:
> >
> >      R --interactive -e 'source("script.R")'
> >
> > or we could shorten it to:
> >
> >      R --interactive -e 'browser()'
> >
> > However, it seems that --interactive causes -e to be ignored.
> >
> > And if I leave out --interactive, then R quits before the browser()
function exits.
> >
> >  From an engineering standpoint it doesn't seem like it should be
very difficult to tell the interactive REPL to pretend that a certain command
was entered before everything else. Also, it would be useful to me to be able to
debug R scripts using standard features like 'browser()'. Should I
submit a feature request on Bugzilla, or maybe someone can advise me how to
proceed?
> >
> > Thanks,
> >
> > Frederick
> >
> > ______________________________________________
> > R-devel at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-devel