[R] [beginner] simple keyword to exit script ?

[Petr Savicky]

On Sun, Nov 21, 2010 at 10:56:14AM -0500, David Winsemius wrote:
> On Nov 21, 2010, at 10:43 AM, madr wrote:
> >Is there any way of suppressing that error, like in other programming
> >languages you can specifically invoke an error or simply exit,
> 
> If you are in a function, then return()
> 
> >like after
> >user input, exiting then is not always identical with error , there  
> >are
> >cases when it is intended behavior. I thought R makes that  
> >distinction.
> 
> Provide some code. (You did say you had a script.)  The answer  
> probably depends on context and you are not providing any.

A script may reach a condition, when it should stop in different
situations. It need not be called using source(). It may be a
function called from an extension package. If there is a sequence
of several embedded calls than return() cannot be used.

For scripts, which i use myself, i use stop() with a parameter,
which is a character string explaining the stopping condition.
This string is then a part of the generated error message.

For scripts, which are used also by other people, i try to avoid
this and make sure that after reaching a stopping condition, all
cycles and function calls are finished.

PS.