[Rd] Bounty on Error Checking

Matthew Dowle mdowle at mdowle.plus.com
Thu Jan 3 20:28:43 CET 2013


That's standard R behaviour. But I've had similar bugs
as you.

If you really want to change it then one way would be to
create your own helper function, say strictselect(), or
shorter name and ensure to use that instead of [[ and $.

Or, how about something like this? :

> DF = data.frame(a=1:3,b=4:6)
> DF$foo
> DF[["foo"]]
> "$.data.frame" = "[[.data.frame" = function(x,...) {
     if (!..1 %in% names(x)) stop("Column not found!")
     else base::"[[.data.frame"(x,...)
> DF$foo
Error in `$.data.frame`(DF, foo) : Column not found!
> DF[["foo"]]
Error in `[[.data.frame`(DF, "foo") : Column not found!
> DF[["newcol"]] <- 7:9
> DF
   a b newcol
1 1 4      7
2 2 5      8
3 3 6      9

Masking those methods in your .GlobalEnv shouldn't break
packages that may rely on missing columns returning NULL
because all packages now have namespaces. So this mask
should just affect your own code, iiuc.

You could place those masks into your Rprofile.site.

It was quickly typed and tested, and not thoroughly
thought through, so *it is just a straw man*.


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