On Fri, 2004-02-27 at 07:10, "Jens OehlschlÃgel" wrote: > Dear R-experts, > > I just tracked down a nasty bug in a dynamically parametrized function to > wrong argument matching. As we get more and more complex applications build on > top of R (like bioconductor) partial matching gets more and more dangerous. I > would like to deactivate partial matching in R (partial argument matching as > well as partial matching of list elements), e.g. using an environment > variable. If this is currently not possible this would be my current most important > wishlist topic.
As a temporary solution for the argument matching issue, you could modify the code for match.arg() and add a T/F 'exact' argument, thus using either match() or pmatch(), the latter of which is the present default. match.arg() is a fairly short function. my.match.arg <- function (arg, choices, exact = FALSE) { if (missing(choices)) { formal.args <- formals(sys.function(sys.parent())) choices <- eval(formal.args[[deparse(substitute(arg))]]) } if (all(arg == choices)) return(choices[1]) # HERE IS THE MODIFIED CODE if (exact) i <- match(arg, choices) else i <- pmatch(arg, choices) # END MODIFIED CODE if (is.na(i)) stop(paste("ARG should be one of", paste(choices, collapse = ", "), sep = " ")) if (length(i) > 1) stop("there is more than one match in match.arg") choices[i] } I did not add any additional error checking code here or how you want to handle non-matches, since that maybe unique to your application. I am not sure what you are using for list element matching (charmatch?), but a similar approach can feasibly be taken there, keeping in mind that charmatch() is a .Internal. In terms of global variables, you can always add one to your environment (ie. using .Rprofile). In that case, you could use the following in place of the four lines above, after setting options(exact) to a default value (ie. options(exact = TRUE) ): if (options()$exact) i <- match(arg, choices) else i <- pmatch(arg, choices) You would of course need to ensure that options()$exact is unique based upon the addition of non-base packages and then leave off the 'exact' argument as I have the function defined above. I hope that this helps, keeping in mind I am only on my first cup of coffee so far this morning... :-) Marc Schwartz ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html