[R] assert( condition )

[Thomas Lumley]

On Tue, 6 Apr 2004, ivo welch wrote:

>
> hi R wizards:  I think it would be a good idea for me to use basic
> argument checking (type, length) in function calls via an assert() like
> function.  How do people usually do this?  Should I define my own
> "assert()" function (or are there some predefined assertions)?  If I
> write my own assert, is it possible to print out the R internal call
> stack?  thanks.
>

In the R testing suite the stopifnot() function does this. After stopping,
traceback() will print out the R stack trace.

A more elegant solution would use the new R condition mechanism and allow
assertion failures to be caught independently of errors.

	-thomas