On 05/09/2022 10:48 p.m., Jiří Moravec wrote:
Hello,
this is my first time writing C code that interacts with R.
To make my C code more modular, reusable, and easier to test with
unittests, I split my code into:
a) code that does stuff
b) code that interfaces between a) and R.
Only the b) imports the R headers, a) is completely independent of R
(and potentially shared between different projects).
That brings me to a problem: How to do error handling in C without the
use of various C-specific print functions R-specific print functions?
The C-specific print functions raise a CRAN note:
Compiled code should not call entry points which might terminate R nor
write to stdout/stderr instead of to the console, nor use Fortran I/O
nor system RNGs
But R(C) print functions cannot be used without importing particular
header,
which would induce otherwise another dependency, and tie it closely with R.
I think the best way is to think of error reporting as part of the
interface. Your code that does stuff shouldn't try to print anything,
it should just return special error code values to indicate problems.
The code in b) looks for those error codes and creates R messages or
errors. If you use the a) code in a different project, it would do the
same, but report the errors in whatever way is natural in that context.
This is my first time writing into mailing list, hopefully I am doing
everything ok.
Looks fine to me!
Duncan Murdoch
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