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Control statements with condition with greater than one should give error (not just warning) [PATCH]

11 messages · Henrik Bengtsson, Martin Maechler, Hadley Wickham +3 more

Original
Henrik Bengtsson
# 
I'd like to propose that the whenever the length of condition passed
to an if or a while statement differs from one, an error is produced
rather than just a warning as today:
x == 1
Warning message:
In if (x == 1) message("x == 1") :
  the condition has length > 1 and only the first element will be used

There are probably legacy reasons for why this is accepted by R in the
first place, but I cannot imagine than anyone wants to use an if/while
statement this way on purpose.  The warning about this misuse, was
introduced in November 2002 (R-devel thread 'vector arguments to
if()'; https://stat.ethz.ch/pipermail/r-devel/2002-November/025537.html).

Below is patch (also attached) that introduces option
'check.condition' such that when TRUE, it will generate an error
rather than a warning (default).  This option allows for a smooth
migration as it can be added to 'R CMD check --as-cran' and developers
can give time to check and fix their packages.  Eventually,
check.condition=TRUE can become the new default.

With options(check.condition = TRUE), one gets:
Error in if (x == 1) message("x == 1") : the condition has length > 1

and
Error in while (x < 2) message("x < 2") : the condition has length > 1


Index: src/library/base/man/options.Rd
===================================================================
--- src/library/base/man/options.Rd (revision 72298)
+++ src/library/base/man/options.Rd (working copy)
@@ -86,6 +86,11 @@
       vector (atomic or \code{\link{list}}) is extended, by something
       like \code{x <- 1:3; x[5] <- 6}.}

+    \item{\code{check.condition}:}{logical, defaulting to \code{FALSE}.  If
+      \code{TRUE}, an error is produced whenever the condition to an
+      \code{if} or a \code{while} control statement is of length greater
+      than one.  If \code{FALSE}, a \link{warning} is produced.}
+
     \item{\code{CBoundsCheck}:}{logical, controlling whether
       \code{\link{.C}} and \code{\link{.Fortran}} make copies to check for
       array over-runs on the atomic vector arguments.
@@ -445,6 +450,7 @@
   \tabular{ll}{
     \code{add.smooth} \tab \code{TRUE}\cr
     \code{check.bounds} \tab \code{FALSE}\cr
+    \code{check.condition} \tab \code{FALSE}\cr
     \code{continue} \tab \code{"+ "}\cr
     \code{digits} \tab \code{7}\cr
     \code{echo} \tab \code{TRUE}\cr
Index: src/library/utils/R/completion.R
===================================================================
--- src/library/utils/R/completion.R (revision 72298)
+++ src/library/utils/R/completion.R (working copy)
@@ -1304,8 +1304,8 @@
           "plt", "ps", "pty", "smo", "srt", "tck", "tcl", "usr",
           "xaxp", "xaxs", "xaxt", "xpd", "yaxp", "yaxs", "yaxt")

-    options <- c("add.smooth", "browser", "check.bounds", "continue",
- "contrasts", "defaultPackages", "demo.ask", "device",
+    options <- c("add.smooth", "browser", "check.bounds", "check.condition",
+        "continue", "contrasts", "defaultPackages", "demo.ask", "device",
  "digits", "dvipscmd", "echo", "editor", "encoding",
  "example.ask", "expressions", "help.search.types",
  "help.try.all.packages", "htmlhelp", "HTTPUserAgent",
Index: src/main/eval.c
===================================================================
--- src/main/eval.c (revision 72298)
+++ src/main/eval.c (working copy)
@@ -1851,9 +1851,13 @@
     Rboolean cond = NA_LOGICAL;

     if (length(s) > 1) {
+ int check = asInteger(GetOption1(install("check.condition")));
  PROTECT(s); /* needed as per PR#15990.  call gets protected by
warningcall() */
- warningcall(call,
-    _("the condition has length > 1 and only the first element will be used"));
+ if(check != NA_INTEGER && check > 0)
+    errorcall(call, _("the condition has length > 1"));
+ else
+    warningcall(call,
+ _("the condition has length > 1 and only the first element will be used"));
  UNPROTECT(1);
     }
     if (length(s) > 0) {
Index: src/main/options.c
===================================================================
--- src/main/options.c (revision 72298)
+++ src/main/options.c (working copy)
@@ -65,6 +65,7 @@
  * "timeout" ./connections.c

  * "check.bounds"
+ * "check.condition"
  * "error"
  * "error.messages"
  * "show.error.messages"
@@ -248,9 +249,9 @@
     char *p;

 #ifdef HAVE_RL_COMPLETION_MATCHES
+    PROTECT(v = val = allocList(22));
+#else
     PROTECT(v = val = allocList(21));
-#else
-    PROTECT(v = val = allocList(20));
 #endif

     SET_TAG(v, install("prompt"));
@@ -289,6 +290,10 @@
     SETCAR(v, ScalarLogical(0)); /* no checking */
     v = CDR(v);

+    SET_TAG(v, install("check.condition"));
+    SETCAR(v, ScalarLogical(0)); /* no checking */
+    v = CDR(v);
+
     p = getenv("R_KEEP_PKG_SOURCE");
     R_KeepSource = (p && (strcmp(p, "yes") == 0)) ? 1 : 0;


I'm happy to file this via https://bugs.r-project.org, if preferred.

/Henrik
-------------- next part --------------
Index: src/library/base/man/options.Rd
===================================================================
--- src/library/base/man/options.Rd	(revision 72298)
+++ src/library/base/man/options.Rd	(working copy)
@@ -86,6 +86,11 @@
       vector (atomic or \code{\link{list}}) is extended, by something
       like \code{x <- 1:3; x[5] <- 6}.}
 
+    \item{\code{check.condition}:}{logical, defaulting to \code{FALSE}.  If
+      \code{TRUE}, an error is produced whenever the condition to an
+      \code{if} or a \code{while} control statement is of length greater
+      than one.  If \code{FALSE}, a \link{warning} is produced.}
+
     \item{\code{CBoundsCheck}:}{logical, controlling whether
       \code{\link{.C}} and \code{\link{.Fortran}} make copies to check for
       array over-runs on the atomic vector arguments.
@@ -445,6 +450,7 @@
   \tabular{ll}{
     \code{add.smooth} \tab \code{TRUE}\cr
     \code{check.bounds} \tab \code{FALSE}\cr
+    \code{check.condition} \tab \code{FALSE}\cr
     \code{continue} \tab \code{"+ "}\cr
     \code{digits} \tab \code{7}\cr
     \code{echo} \tab \code{TRUE}\cr
Index: src/library/utils/R/completion.R
===================================================================
--- src/library/utils/R/completion.R	(revision 72298)
+++ src/library/utils/R/completion.R	(working copy)
@@ -1304,8 +1304,8 @@
           "plt", "ps", "pty", "smo", "srt", "tck", "tcl", "usr",
           "xaxp", "xaxs", "xaxt", "xpd", "yaxp", "yaxs", "yaxt")
 
-    options <- c("add.smooth", "browser", "check.bounds", "continue",
-	"contrasts", "defaultPackages", "demo.ask", "device",
+    options <- c("add.smooth", "browser", "check.bounds", "check.condition",
+        "continue", "contrasts", "defaultPackages", "demo.ask", "device",
 	"digits", "dvipscmd", "echo", "editor", "encoding",
 	"example.ask", "expressions", "help.search.types",
 	"help.try.all.packages", "htmlhelp", "HTTPUserAgent",
Index: src/main/eval.c
===================================================================
--- src/main/eval.c	(revision 72298)
+++ src/main/eval.c	(working copy)
@@ -1851,9 +1851,13 @@
     Rboolean cond = NA_LOGICAL;
 
     if (length(s) > 1) {
+	int check = asInteger(GetOption1(install("check.condition")));
 	PROTECT(s);	 /* needed as per PR#15990.  call gets protected by warningcall() */
-	warningcall(call,
-		    _("the condition has length > 1 and only the first element will be used"));
+	if(check != NA_INTEGER && check > 0)
+	    errorcall(call, _("the condition has length > 1"));
+	else
+	    warningcall(call,
+			_("the condition has length > 1 and only the first element will be used"));
 	UNPROTECT(1);
     }
     if (length(s) > 0) {
Index: src/main/options.c
===================================================================
--- src/main/options.c	(revision 72298)
+++ src/main/options.c	(working copy)
@@ -65,6 +65,7 @@
  *	"timeout"		./connections.c
 
  *	"check.bounds"
+ *	"check.condition"
  *	"error"
  *	"error.messages"
  *	"show.error.messages"
@@ -248,9 +249,9 @@
     char *p;
 
 #ifdef HAVE_RL_COMPLETION_MATCHES
+    PROTECT(v = val = allocList(22));
+#else
     PROTECT(v = val = allocList(21));
-#else
-    PROTECT(v = val = allocList(20));
 #endif
 
     SET_TAG(v, install("prompt"));
@@ -289,6 +290,10 @@
     SETCAR(v, ScalarLogical(0));	/* no checking */
     v = CDR(v);
 
+    SET_TAG(v, install("check.condition"));
+    SETCAR(v, ScalarLogical(0));	/* no checking */
+    v = CDR(v);
+    
     p = getenv("R_KEEP_PKG_SOURCE");
     R_KeepSource = (p && (strcmp(p, "yes") == 0)) ? 1 : 0;
Martin Maechler
# 
> I'd like to propose that the whenever the length of condition passed
    > to an if or a while statement differs from one, an error is produced
    > rather than just a warning as today:

    >> x <- 1:2
    >> if (x == 1) message("x == 1")
    > x == 1
    > Warning message:
    > In if (x == 1) message("x == 1") :
    > the condition has length > 1 and only the first element will be used

    > There are probably legacy reasons for why this is accepted by R in the
    > first place, but I cannot imagine than anyone wants to use an if/while
    > statement this way on purpose.  The warning about this misuse, was
    > introduced in November 2002 (R-devel thread 'vector arguments to
    > if()'; https://stat.ethz.ch/pipermail/r-devel/2002-November/025537.html).

yes, before, there was *no* warning at all and so the problem existed
in several partly important R packages.

Now is a different time, I agree, and I even tend to agree we
should make this an error... probably however not for the
upcoming R 3.4.0 (in April which is somewhat soon) but rather
for the next version.


    > Below is patch (also attached) that introduces option
    > 'check.condition' such that when TRUE, 

ouch ouch ouch!   There are many sayings starting with
  "The way to hell ...."

Here:

The way to R hell starts (or "widens", your choice) by
introducing options() that influence basic language semantics

!!

For robust code you will start to test all code of R for all
different possible combinations of these options set ---- I am
sure you would not want this.

No --- don't even think of allowing an option for something such basic!

Martin Maechler
ETH Zurich (and R Core)

    > it will generate an error
    > rather than a warning (default).  This option allows for a smooth
    > migration as it can be added to 'R CMD check --as-cran' and developers
    > can give time to check and fix their packages.  Eventually,
    > check.condition=TRUE can become the new default.

    > With options(check.condition = TRUE), one gets:

    >> x <- 1:2
    >> if (x == 1) message("x == 1")
    > Error in if (x == 1) message("x == 1") : the condition has length > 1

    > and

    >> while (x < 2) message("x < 2")
    > Error in while (x < 2) message("x < 2") : the condition has length > 1


    > Index: src/library/base/man/options.Rd
    > ===================================================================
    > --- src/library/base/man/options.Rd (revision 72298)
    > +++ src/library/base/man/options.Rd (working copy)
    > @@ -86,6 +86,11 @@
    > vector (atomic or \code{\link{list}}) is extended, by something
    > like \code{x <- 1:3; x[5] <- 6}.}

    > +    \item{\code{check.condition}:}{logical, defaulting to \code{FALSE}.  If
    > +      \code{TRUE}, an error is produced whenever the condition to an
    > +      \code{if} or a \code{while} control statement is of length greater
    > +      than one.  If \code{FALSE}, a \link{warning} is produced.}
    > +
    > \item{\code{CBoundsCheck}:}{logical, controlling whether
    > \code{\link{.C}} and \code{\link{.Fortran}} make copies to check for
    > array over-runs on the atomic vector arguments.
    > @@ -445,6 +450,7 @@
    > \tabular{ll}{
    > \code{add.smooth} \tab \code{TRUE}\cr
    > \code{check.bounds} \tab \code{FALSE}\cr
    > +    \code{check.condition} \tab \code{FALSE}\cr
    > \code{continue} \tab \code{"+ "}\cr
    > \code{digits} \tab \code{7}\cr
    > \code{echo} \tab \code{TRUE}\cr
    > Index: src/library/utils/R/completion.R
    > ===================================================================
    > --- src/library/utils/R/completion.R (revision 72298)
    > +++ src/library/utils/R/completion.R (working copy)
    > @@ -1304,8 +1304,8 @@
    > "plt", "ps", "pty", "smo", "srt", "tck", "tcl", "usr",
    > "xaxp", "xaxs", "xaxt", "xpd", "yaxp", "yaxs", "yaxt")

    > -    options <- c("add.smooth", "browser", "check.bounds", "continue",
    > - "contrasts", "defaultPackages", "demo.ask", "device",
    > +    options <- c("add.smooth", "browser", "check.bounds", "check.condition",
    > +        "continue", "contrasts", "defaultPackages", "demo.ask", "device",
    > "digits", "dvipscmd", "echo", "editor", "encoding",
    > "example.ask", "expressions", "help.search.types",
    > "help.try.all.packages", "htmlhelp", "HTTPUserAgent",
    > Index: src/main/eval.c
    > ===================================================================
    > --- src/main/eval.c (revision 72298)
    > +++ src/main/eval.c (working copy)
    > @@ -1851,9 +1851,13 @@
    > Rboolean cond = NA_LOGICAL;

    > if (length(s) > 1) {
    > + int check = asInteger(GetOption1(install("check.condition")));
    > PROTECT(s); /* needed as per PR#15990.  call gets protected by
    > warningcall() */
    > - warningcall(call,
    > -    _("the condition has length > 1 and only the first element will be used"));
    > + if(check != NA_INTEGER && check > 0)
    > +    errorcall(call, _("the condition has length > 1"));
    > + else
    > +    warningcall(call,
    > + _("the condition has length > 1 and only the first element will be used"));
    > UNPROTECT(1);
    > }
    > if (length(s) > 0) {
    > Index: src/main/options.c
    > ===================================================================
    > --- src/main/options.c (revision 72298)
    > +++ src/main/options.c (working copy)
    > @@ -65,6 +65,7 @@
    > * "timeout" ./connections.c

    > * "check.bounds"
    > + * "check.condition"
    > * "error"
    > * "error.messages"
    > * "show.error.messages"
    > @@ -248,9 +249,9 @@
    > char *p;

    > #ifdef HAVE_RL_COMPLETION_MATCHES
    > +    PROTECT(v = val = allocList(22));
    > +#else
    > PROTECT(v = val = allocList(21));
    > -#else
    > -    PROTECT(v = val = allocList(20));
    > #endif

    > SET_TAG(v, install("prompt"));
    > @@ -289,6 +290,10 @@
    > SETCAR(v, ScalarLogical(0)); /* no checking */
    > v = CDR(v);

    > +    SET_TAG(v, install("check.condition"));
    > +    SETCAR(v, ScalarLogical(0)); /* no checking */
    > +    v = CDR(v);
    > +
    > p = getenv("R_KEEP_PKG_SOURCE");
    > R_KeepSource = (p && (strcmp(p, "yes") == 0)) ? 1 : 0;


    > I'm happy to file this via https://bugs.r-project.org, if preferred.

    > /Henrik

    > ----------------------------------------------------------------------
    > Index: src/library/base/man/options.Rd
    > ===================================================================
    > --- src/library/base/man/options.Rd	(revision 72298)
    > +++ src/library/base/man/options.Rd	(working copy)
    > @@ -86,6 +86,11 @@
    > vector (atomic or \code{\link{list}}) is extended, by something
    > like \code{x <- 1:3; x[5] <- 6}.}
 
    > +    \item{\code{check.condition}:}{logical, defaulting to \code{FALSE}.  If
    > +      \code{TRUE}, an error is produced whenever the condition to an
    > +      \code{if} or a \code{while} control statement is of length greater
    > +      than one.  If \code{FALSE}, a \link{warning} is produced.}
    > +
    > \item{\code{CBoundsCheck}:}{logical, controlling whether
    > \code{\link{.C}} and \code{\link{.Fortran}} make copies to check for
    > array over-runs on the atomic vector arguments.
    > @@ -445,6 +450,7 @@
    > \tabular{ll}{
    > \code{add.smooth} \tab \code{TRUE}\cr
    > \code{check.bounds} \tab \code{FALSE}\cr
    > +    \code{check.condition} \tab \code{FALSE}\cr
    > \code{continue} \tab \code{"+ "}\cr
    > \code{digits} \tab \code{7}\cr
    > \code{echo} \tab \code{TRUE}\cr
    > Index: src/library/utils/R/completion.R
    > ===================================================================
    > --- src/library/utils/R/completion.R	(revision 72298)
    > +++ src/library/utils/R/completion.R	(working copy)
    > @@ -1304,8 +1304,8 @@
    > "plt", "ps", "pty", "smo", "srt", "tck", "tcl", "usr",
    > "xaxp", "xaxs", "xaxt", "xpd", "yaxp", "yaxs", "yaxt")
 
    > -    options <- c("add.smooth", "browser", "check.bounds", "continue",
    > -	"contrasts", "defaultPackages", "demo.ask", "device",
    > +    options <- c("add.smooth", "browser", "check.bounds", "check.condition",
    > +        "continue", "contrasts", "defaultPackages", "demo.ask", "device",
    > "digits", "dvipscmd", "echo", "editor", "encoding",
    > "example.ask", "expressions", "help.search.types",
    > "help.try.all.packages", "htmlhelp", "HTTPUserAgent",
    > Index: src/main/eval.c
    > ===================================================================
    > --- src/main/eval.c	(revision 72298)
    > +++ src/main/eval.c	(working copy)
    > @@ -1851,9 +1851,13 @@
    > Rboolean cond = NA_LOGICAL;
 
    > if (length(s) > 1) {
    > +	int check = asInteger(GetOption1(install("check.condition")));
    > PROTECT(s);	 /* needed as per PR#15990.  call gets protected by warningcall() */
    > -	warningcall(call,
    > -		    _("the condition has length > 1 and only the first element will be used"));
    > +	if(check != NA_INTEGER && check > 0)
    > +	    errorcall(call, _("the condition has length > 1"));
    > +	else
    > +	    warningcall(call,
    > +			_("the condition has length > 1 and only the first element will be used"));
    > UNPROTECT(1);
    > }
    > if (length(s) > 0) {
    > Index: src/main/options.c
    > ===================================================================
    > --- src/main/options.c	(revision 72298)
    > +++ src/main/options.c	(working copy)
    > @@ -65,6 +65,7 @@
    > *	"timeout"		./connections.c
 
    > *	"check.bounds"
    > + *	"check.condition"
    > *	"error"
    > *	"error.messages"
    > *	"show.error.messages"
    > @@ -248,9 +249,9 @@
    > char *p;
 
    > #ifdef HAVE_RL_COMPLETION_MATCHES
    > +    PROTECT(v = val = allocList(22));
    > +#else
    > PROTECT(v = val = allocList(21));
    > -#else
    > -    PROTECT(v = val = allocList(20));
    > #endif
 
    > SET_TAG(v, install("prompt"));
    > @@ -289,6 +290,10 @@
    > SETCAR(v, ScalarLogical(0));	/* no checking */
    > v = CDR(v);
 
    > +    SET_TAG(v, install("check.condition"));
    > +    SETCAR(v, ScalarLogical(0));	/* no checking */
    > +    v = CDR(v);
    > +    
    > p = getenv("R_KEEP_PKG_SOURCE");
    > R_KeepSource = (p && (strcmp(p, "yes") == 0)) ? 1 : 0;
 

    > ----------------------------------------------------------------------
    > ______________________________________________
    > R-devel at r-project.org mailing list
    > https://stat.ethz.ch/mailman/listinfo/r-devel
Henrik Bengtsson
# 
On Fri, Mar 3, 2017 at 9:22 AM, Martin Maechler
<maechler at stat.math.ethz.ch> wrote:
You only want to test with check.condition = TRUE.  No new code,
package updates etc should be allowed to only pass if they have to use
check.condition = FALSE.
But, how you propose a warning-to-error transition should be made
without wreaking havoc?  Just flip the switch in R-devel and see CRAN
and Bioconductor packages break overnight?  Particularly Bioconductor
devel might become non-functional (since at times it requires
R-devel).  For my own code / packages, I would be able to handle such
a change, but I'm completely out of control if one of the package I'm
depending on does not provide a quick fix (with the only option to
remove package tests for those dependencies).

My idea is that with this option, then this can be tested at runtime
locally by users and developers (cf. warnPartialMatchArgs), but also
via R CMD check.  It would also provide CRAN with a way to check it on
incoming submissions as on the test farm - eventually all CRAN
packages pass without errors.  This option would only exist for a
number of R releases (first default to FALSE, then TRUE) and then
eventually be deprecated and removed.  Does this clarify my design?

As an alternative to an option, one could use an environment variable
R_CHECK_CONDITION that is a bit "hidden" from misuse.

/Henrik
Hadley Wickham
# 
Generally, a package can not be on CRAN if it has any warnings, so I
don't think this change would have any impact on CRAN packages.  Isn't
this also true for bioconductor?

Hadley
Henrik Bengtsson
#
On Fri, Mar 3, 2017 at 9:55 AM, Hadley Wickham <h.wickham at gmail.com> wrote:
Having a tests/warn.R file with:

warning("boom")

passes through R CMD check --as-cran unnoticed.  Same with:

if (sample(2) == 1) message("It's your lucky day today!")

/Henrik

PS. Does testthat signal that?
1 day later
Martin Maechler
# 
> On Fri, Mar 3, 2017 at 9:55 AM, Hadley Wickham
> <h.wickham at gmail.com> wrote:
>>> But, how you propose a warning-to-error transition
    >>> should be made without wreaking havoc?  Just flip the
    >>> switch in R-devel and see CRAN and Bioconductor packages
    >>> break overnight?  Particularly Bioconductor devel might
    >>> become non-functional (since at times it requires
    >>> R-devel).  For my own code / packages, I would be able
    >>> to handle such a change, but I'm completely out of
    >>> control if one of the package I'm depending on does not
    >>> provide a quick fix (with the only option to remove
    >>> package tests for those dependencies).
    >> 
    >> Generally, a package can not be on CRAN if it has any
    >> warnings, so I don't think this change would have any
    >> impact on CRAN packages.  Isn't this also true for
    >> bioconductor?

    > Having a tests/warn.R file with:

    > warning("boom")

    > passes through R CMD check --as-cran unnoticed.  

Yes, indeed.. you are right Henrik  that many/most R warning()s would
not produce  R CMD check  'WARNING's ..

I think Hadley and I fell into the same mental pit of concluding
that such warning()s  from   if(<length-larger-one>)  ...
would not currently happen in CRAN / Bioc packages and hence
turning them to errors would not have a direct effect.

With your 2nd e-mail of saying that you'd propose such an option
only for a few releases of R you've indeed clarified your intent
to me.
OTOH, I would prefer using an environment variable (as you've
proposed as an alternative)  which is turned "active"  at the
beginning only manually or  for the  "CRAN incoming" checks of
the CRAN team (and bioconductor submission checks?)
and later for  '--as-cran'  etc until it eventually becomes the
unconditional behavior of R (and the env.variable is no longer used).

Martin
Michael Lawrence
# 
Is there really a need for these complications? Packages emitting this
warning are broken by definition and should be fixed. Perhaps we could
"flip the switch" in a test environment and see how much havoc is wreaked
and whether authors are sufficiently responsive?

Michael

On Sat, Mar 4, 2017 at 12:04 PM, Martin Maechler <maechler at stat.math.ethz.ch

  
  


  


      

    

    

      
      

        


  

        

      Henrik Bengtsson
    

    

      
      #
    

  


  

      
Here's a patch that enables the error if
_R_CHECK_CONDITION_={1,true,TRUE,yes,YES}.

$ svn diff
Index: src/main/eval.c
===================================================================
--- src/main/eval.c (revision 72303)
+++ src/main/eval.c (working copy)
@@ -1851,9 +1851,19 @@
     Rboolean cond = NA_LOGICAL;

     if (length(s) > 1) {
+ int val = 0; /* warn by default */
+ char *check = getenv("_R_CHECK_CONDITION_");
+ if (check != NULL) {
+    val = (strcmp("1", check) == 0 ||
+           strcasecmp("true", check) == 0 ||
+   strcasecmp("yes", check) == 0);
+        }
  PROTECT(s); /* needed as per PR#15990.  call gets protected by
warningcall() */
- warningcall(call,
-    _("the condition has length > 1 and only the first element will be used"));
+ if (val)
+    errorcall(call, _("the condition has length > 1"));
+        else
+    warningcall(call,
+ _("the condition has length > 1 and only the first element will be used"));
  UNPROTECT(1);
     }
     if (length(s) > 0) {

An alternative is to make _R_CHECK_CONDITION_=false the default behavior.


With this env variable, I think it'll be easier for a developer to
temporarily work around broken dependencies until fixed.  It will also
help identify broken dependencies.  For instance, as soon as one is
identified it can be wrapped up in an:

  with_faulty_conditions(x <- pkg::foo(...))

and additionally faulty if/while statements can be detected.  Your
package will still "work" until downstream packages are fixed.  Here,

with_faulty_conditions <- function(expr, envir = parent.frame()) {
  oenv <- Sys.getenv("_R_CHECK_CONDITION_")
  on.exit(Sys.setenv("_R_CHECK_CONDITION_" = oenv))
  Sys.setenv("_R_CHECK_CONDITION_" = FALSE)
  eval(substitute(expr), envir = envir)
}

/Henrik

On Sat, Mar 4, 2017 at 12:20 PM, Michael Lawrence

        
<lawrence.michael at gene.com> wrote:

            

      
      
      
    

        

      
      
    

            

      
      
      
    

  
  


  


      

    

    
1 day later

    

      
      

        


  

        

      Martin Maechler
    

    

      
      #
    

  


  

          

      
      
      
    

        
> Is there really a need for these complications? Packages
    > emitting this warning are broken by definition and should be fixed. 

I agree and probably Henrik, too.

(Others may disagree to some extent .. and find it convenient
 that R does translate 'if(x)'  to  'if(x[1])'  for them albeit
 with a warning .. )

    > Perhaps we could "flip the switch" in a test
    > environment and see how much havoc is wreaked and whether
    > authors are sufficiently responsive?

    > Michael

As we have > 10'000 packages on CRAN alonce,  and people have
started (mis)using suppressWarnings(.) in many places,  there
may be considerably more packages affected than we optimistically assume...

As R core member who would  "flip the switch"  I'd typically then
have to be the one sending an e-mail to all package maintainers
affected.... and in this case I'm very reluctant to volunteer
for that and so, I'd prefer the environment variable where R
core and others can decide how to use it .. for a while .. until
the flip is switched for all.

or have I overlooked an issue?

Martin

    > On Sat, Mar 4, 2017 at 12:04 PM, Martin Maechler
    > <maechler at stat.math.ethz.ch

        
>> wrote:

        
>> >>>>> Henrik Bengtsson <henrik.bengtsson at gmail.com> >>>>>
    >> on Fri, 3 Mar 2017 10:10:53 -0800 writes:
    >> 
    >> > On Fri, Mar 3, 2017 at 9:55 AM, Hadley Wickham >
    >> <h.wickham at gmail.com> wrote: >>> But, how you propose a
    >> warning-to-error transition >>> should be made without
    >> wreaking havoc?  Just flip the >>> switch in R-devel and
    >> see CRAN and Bioconductor packages >>> break overnight?
    >> Particularly Bioconductor devel might >>> become
    >> non-functional (since at times it requires >>> R-devel).
    >> For my own code / packages, I would be able >>> to handle
    >> such a change, but I'm completely out of >>> control if
    >> one of the package I'm depending on does not >>> provide
    >> a quick fix (with the only option to remove >>> package
    >> tests for those dependencies).
    >> >>
    >> >> Generally, a package can not be on CRAN if it has any
    >> >> warnings, so I don't think this change would have any
    >> >> impact on CRAN packages.  Isn't this also true for >>
    >> bioconductor?
    >> 
    >> > Having a tests/warn.R file with:
    >> 
    >> > warning("boom")
    >> 
    >> > passes through R CMD check --as-cran unnoticed.
    >> 
    >> Yes, indeed.. you are right Henrik that many/most R
    >> warning()s would not produce R CMD check 'WARNING's ..
    >> 
    >> I think Hadley and I fell into the same mental pit of
    >> concluding that such warning()s from
    >> if(<length-larger-one>) ...  would not currently happen
    >> in CRAN / Bioc packages and hence turning them to errors
    >> would not have a direct effect.
    >> 
    >> With your 2nd e-mail of saying that you'd propose such an
    >> option only for a few releases of R you've indeed
    >> clarified your intent to me.  OTOH, I would prefer using
    >> an environment variable (as you've proposed as an
    >> alternative) which is turned "active" at the beginning
    >> only manually or for the "CRAN incoming" checks of the
    >> CRAN team (and bioconductor submission checks?)  and
    >> later for '--as-cran' etc until it eventually becomes the
    >> unconditional behavior of R (and the env.variable is no
    >> longer used).
    >> 
    >> Martin
    >> 
    >> ______________________________________________
    >> R-devel at r-project.org mailing list
    >> https://stat.ethz.ch/mailman/listinfo/r-devel
    >> 

    > 	[[alternative HTML version deleted]]

  
  


  


      

    

    
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      Karl Millar
    

    

      
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Is there anything that actually requires R core members to manually do
significant amounts of work here?

IIUC, you can do a CRAN run to detect the broken packages, and a simple
script can collect the emails of the affected maintainers, so you can send
a single email to them all.  If authors don't respond by fixing their
packages, then those packages should be archived, since there's high
probability of those packages being buggy anyway.

If you expect a non-trivial amount of questions regarding this change from
the affected package maintainers, then you can create a FAQ page for it,
which you can fill in as questions arrive, so you don't get too many
duplicated questions.

Karl

On Mon, Mar 6, 2017 at 4:51 AM, Martin Maechler <maechler at stat.math.ethz.ch>
wrote:

            

      
      
      
    

        

      
      
    

        

  
  


  


      

    

    

      
      

        


  

        

      Gabriel Becker
    

    

      
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I'm just throwing this out there, but maybe CRAN (or some other testing
machinery) should get a "strict testing" build of R in which
suppressWarnings is reassigned to identity...

Or maybe suppressWarnings could check for, eg an environment variable and
turn itself into a no-op when present, so that build systems could be used
to test for this.

~G

On Tue, Mar 7, 2017 at 11:45 AM, Karl Millar via R-devel <

        
r-devel at r-project.org> wrote: