Hi All, I am one of the contributors to the FastR project ( https://bitbucket.org/allr <https://bitbucket.org/allr.>) and I have encountered an interesting issue when trying to implement vector accesses within FastR. I am trying to understand what kind of error message should be generated for the following expression:
x<-1:4; x[[1]]<-NULL; x In order to determine the error message, I ran the shell of standard GNU R (installed via MacPorts - R version 2.15.3) on Mac OS X 10.8.5 as follows, with R metadata (that is .RData or .Rhistory files) removed from the current directory (I have edited portions of the R header printed when the shell starts for the sake for readability): Adams-MacBook-Air:work adam$ R R version 2.15.3 (2013-03-01) -- "Security Blanket" Copyright (C) 2013 The R Foundation for Statistical Computing ISBN 3-900051-07-0 Platform: x86_64-apple-darwin12.3.0/x86_64 (64-bit) ... ... Type 'q()' to quit R. > x<-1:4; x[[1]]<-NULL; x Error in x[[1]] <- NULL : incompatible types (from NULL to integer) in [[ assignment > q() Save workspace image? [y/n/c]: n Adams-MacBook-Air:work adam$ R R version 2.15.3 (2013-03-01) -- "Security Blanket" Copyright (C) 2013 The R Foundation for Statistical Computing ISBN 3-900051-07-0 Platform: x86_64-apple-darwin12.3.0/x86_64 (64-bit) ... ... Type 'q()' to quit R. > x<-1:4; x[[1]]<-NULL; x Error in x[[1]] <- NULL : more elements supplied than there are to replace > As you can see, the error message for the same expression is different on two subsequent executions of the GNU R shell (with no workspace image saving - but it does not matter, as I observe the same behavior if the workspace is saved). I tried the same thing on Linux, but there the behavior seems consistent (the second message is displayed in each execution). This issue is not specific to this single expression - it happens in other (though not all) cases when the NULL value is assigned to an element of a vector. I was wondering if someone has observed the same behavior and perhaps knows what may be causing it... Thank you Adam [[alternative HTML version deleted]] ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel