R devel - May 2025 - Bug in prettyNum

Dear list,

I'd like to report a bug in `prettyNum()`. When called with a numeric
vector, the `replace.zero` argument is disregarded.
> prettyNum(0, zero.print = "- ", replace.zero = TRUE)
[1] "-"
Warning message:
In .format.zeros(x, zero.print, replace = replace.zero) :
  'zero.print' is truncated to fit into formatted zeros; consider
'replace=TRUE'

A character vector as input works as expected:
> prettyNum("0", zero.print = "- ", replace.zero = TRUE)
[1] "- "

Please see below a patch which I believe would fix this. I haven't tested it
as I can't easily compile R from source with my setup.

Best,

Mikko

diff --git a/src/library/base/R/format.R b/src/library/base/R/format.R
index 63fef83..1afadd3 100644
--- a/src/library/base/R/format.R
+++ b/src/library/base/R/format.R
@@ -338,7 +338,7 @@ prettyNum <-
                    big.mark=big.mark, big.interval=big.interval,
                    small.mark=small.mark, small.interval=small.interval,
                    decimal.mark=decimal.mark, zero.print=zero.print,
-                   drop0trailing=drop0trailing, ...)
+                   replace.zero=replace.zero, drop0trailing=drop0trailing, ...)
     }
     ## be fast in trivial case, when all options have their default, or
"match"
     nMark <- big.mark == "" && small.mark == ""
&& (notChar || decimal.mark == input.d.mark)


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Thank you.

? Fri, 23 May 2025 11:47:33 +0000
Marttila Mikko via R-devel <r-devel at r-project.org> ?????:
> When called with a numeric vector, the `replace.zero` argument is
> disregarded.
> 
> > prettyNum(0, zero.print = "- ", replace.zero = TRUE)  
> [1] "-"
> Warning message:
> In .format.zeros(x, zero.print, replace = replace.zero) :
>   'zero.print' is truncated to fit into formatted zeros; consider
> 'replace=TRUE'
> Please see below a patch which I believe would fix this.
Surprisingly, it's not enough. The 'replace' argument to
.format.zeros
needs to be "threaded" through both the call to vapply(x, format, ...)
and the internal call from format.default(...) to prettyNum(...):

R> options(warn = 2, error = recover)
R> prettyNum(0, zero.print = "--", replace.zero = TRUE)
Error in .format.zeros(x, zero.print, replace = replace.zero) :
  (converted from warning) 'zero.print' is truncated to fit into
formatted zeros; consider 'replace=TRUE'

Enter a frame number, or 0 to exit

 1: prettyNum(0, zero.print = "--", replace.zero = TRUE)
 2: vapply(x, format, "", big.mark = big.mark, big.interval =
big.interval, sma
 3: FUN(X[[i]], ...)
 4: format.default(X[[i]], ...)
 5: prettyNum(.Internal(format(x, trim, digits, nsmall, width, 3, na.encode, sc
 6: .format.zeros(x, zero.print, replace = replace.zero)
 7: warning("'zero.print' is truncated to fit into formatted zeros;
consider 'r
<...omitted...>
Selection: 6
<...>
Browse[1]> ls.str()
i0 :  logi TRUE
ind0 :  int 1
nc :  int 1
nx :  num 0
nz :  int 2
replace :  logi FALSE
warn.non.fitting :  logi TRUE
x :  chr "0"
zero.print :  chr "--"

Since prettyNum() accepts ... and thus ignores unknown arguments, it
seems to be safe to forward the ellipsis from format.default() to
prettyNum(). The patch survives LANGUAGE=en TZ=UTC make check-devel.

Index: src/library/base/R/format.R
==================================================================---
src/library/base/R/format.R	(revision 88229)
+++ src/library/base/R/format.R	(working copy)
@@ -73,7 +73,7 @@
 			     decimal.mark = decimal.mark, input.d.mark = decimal.mark,
 			     zero.print = zero.print, drop0trailing = drop0trailing,
 			     is.cmplx = is.complex(x),
-			     preserve.width = if (trim) "individual" else
"common"),
+			     preserve.width = if (trim) "individual" else
"common", ...),
 	       ## all others (for now):
 	       stop(gettextf("Found no format() method for class
\"%s\"",
 			     class(x)), domain = NA))
@@ -338,7 +338,8 @@
 		    big.mark=big.mark, big.interval=big.interval,
 		    small.mark=small.mark, small.interval=small.interval,
 		    decimal.mark=decimal.mark, zero.print=zero.print,
-		    drop0trailing=drop0trailing, ...)
+		    drop0trailing=drop0trailing, replace.zero=replace.zero,
+		    ...)
     }
     ## be fast in trivial case, when all options have their default, or
"match"
     nMark <- big.mark == "" && small.mark == ""
&& (notChar || decimal.mark == input.d.mark)


-- 
Best regards,
Ivan