more tweaks for macOS 14

git-svn-id: https://svn.r-project.org/R/trunk@85246 00db46b3-68df-0310-9c12-caf00c1e9a41

src/library/base/man/iconv.Rd

@@ -78,21 +78,23 @@ iconvlist()
 \section{Implementation Details}{
   There are three main implementations of \code{iconv} in use.  Linux's
   most common C runtime, \samp{glibc}, contains one.  Several platforms
-  supply versions of GNU \samp{libiconv}, including macOS and FreeBSD, in
-  some cases with additional encodings.  On Windows we use a version of
-  Yukihiro Nakadaira's \samp{win_iconv}, which is based on Windows'
-  codepages.  (We have added many encoding names for compatibility with
-  other systems.)  All three have \code{iconvlist}, ignore case in
-  encoding names and support \samp{//TRANSLIT} (but with different
-  results, and for \samp{win_iconv} currently a \sQuote{best fit}
-  strategy is used except for \code{to = "ASCII"}).
+  supply versions or emulations of GNU \samp{libiconv}, including macOS
+  and FreeBSD, in some cases with additional encodings.  On Windows we
+  use a version of Yukihiro Nakadaira's \samp{win_iconv}, which is based
+  on Windows' codepages.  (We have added many encoding names for
+  compatibility with other systems.)  All three have \code{iconvlist},
+  ignore case in encoding names and support \samp{//TRANSLIT} (but with
+  different results, and for \samp{win_iconv} currently a \sQuote{best
+  fit} strategy is used except for \code{to = "ASCII"}).
 
   %% https://github.com/apple-oss-distributions/libiconv/blob/libiconv-80.1.1/citrus/iconv.h
-  The macOS implementation is attributed to the \sQuote{Citrus Project}:
-  the Apple sources declare it as \sQuote{compatible} with GNU \samp{libiconv}
-  1.11 from 2006.  However, it is has diverged notably since and in macOS
-  14 uses a \sQuote{best fit} for conversions at least for \code{to =
-  "ASCII"} and \code{to = "latin1"}.
+  The macOS 14 implementation is attributed to the \sQuote{Citrus
+  Project}: the Apple headers declare it as \sQuote{compatible} with GNU
+  \samp{libiconv} 1.11 from 2006.  However, it differs in
+  significant ways including using a \sQuote{best fit} for conversions,
+  at least for \code{to = "ASCII"} and \code{to = "latin1"}.  (Earlier
+  versions of macOS used GNU \samp{libiconv} 1.11. It seems this
+  implementation is also used in recent versions of FreeBSD.)
 
   Most commercial Unixes contain an implementation of \code{iconv} but
   none we have encountered have supported the encoding names we need:
@@ -108,16 +110,15 @@ iconvlist()
 
   There are other implementations, e.g.\sspace{} NetBSD has used one from the
   Citrus project (which does not support \samp{//TRANSLIT}) and there is
-  an older FreeBSD port (\samp{libiconv} is usually used there): it has
-  not been reported whether or not these work with \R.
+  an older FreeBSD port.
 
   Note that you cannot rely on invalid inputs being detected, especially
   for \code{to = "ASCII"} where some implementations allow 8-bit
   characters and pass them through unchanged or with transliteration or
   substitution.
 
   Some of the implementations have interesting extra encodings: for
-  example GNU \samp{libiconv} allows \code{to = "C99"} to use
+  example GNU \samp{libiconv} and macOS 14 allow \code{to = "C99"} to use
   \samp{\\uxxxx} escapes (or if needed \samp{\Uuxxxxxxxx}) for
   non-ASCII characters.
 }
@@ -215,6 +216,9 @@ Encoding(x) <- "latin1"
 x
 try(iconv(x, "latin1", "ASCII//TRANSLIT"))  # platform-dependent
 iconv(x, "latin1", "ASCII", sub = "byte")
+## glibc gives "Ekstroem" "Joreskog" "bisschen Zurcher"
+## macOS 14 gives "Ekstrom" "J\"oreskog" "bisschen Z\"urcher"
+
 ## and for Windows' 'Unicode'
 str(xx <- iconv(x, "latin1", "UTF-16LE", toRaw = TRUE))
 iconv(xx, "UTF-16LE", "UTF-8")