bug#66178: 30.0.50; cperl-mode inconsistent hash key fontification

bug#66178: 30.0.50; cperl-mode inconsistent hash key fontification

[Mauro Aranda]

emacs -Q
C-x C-f bug.pl
M-x cperl-mode
my %factorial = (
          0 => 1,
          zero => 1
         );

zero is recognized as a string, 0 is not.


In GNU Emacs 30.0.50 (build 11, x86_64-pc-linux-gnu, GTK+ Version
  3.24.33, cairo version 1.16.0) of 2023-09-24 built on tbb-desktop
Repository revision: 38cd3cb4330f2c18d01fa6aa7eb54623cecab522
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12201001
System Description: Ubuntu 22.04.2 LTS

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ JPEG
JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2 M17N_FLT MODULES NOTIFY
INOTIFY PDUMPER PNG RSVG SECCOMP SOUND SQLITE3 THREADS TIFF
TOOLKIT_SCROLL_BARS TREE_SITTER X11 XDBE XIM XINPUT2 XPM GTK3 ZLIB

Important settings:
   value of $LC_MONETARY: es_AR.UTF-8
   value of $LC_NUMERIC: es_AR.UTF-8
   value of $LC_TIME: es_AR.UTF-8
   value of $LANG: en_US.UTF-8
   value of $XMODIFIERS: @im=ibus
   locale-coding-system: utf-8-unix

Major mode: CPerl

Minor modes in effect:
   tooltip-mode: t
   global-eldoc-mode: t
   show-paren-mode: t
   electric-indent-mode: t
   mouse-wheel-mode: t
   tool-bar-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   minibuffer-regexp-mode: t
   line-number-mode: t
   indent-tabs-mode: t
   transient-mark-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t

Load-path shadows:
None found.

Features:
(shadow sort mail-extr emacsbug message mailcap yank-media puny dired
dired-loaddefs rfc822 mml mml-sec password-cache epa derived epg rfc6068
epg-config gnus-util text-property-search time-date subr-x mm-decode
mm-bodies mm-encode mail-parse rfc2231 mailabbrev gmm-utils mailheader
cl-loaddefs cl-lib sendmail rfc2047 rfc2045 ietf-drums mm-util
mail-prsvr mail-utils cperl-mode rx facemenu perl-mode rmc iso-transl
tooltip cconv eldoc paren electric uniquify ediff-hook vc-hooks
lisp-float-type elisp-mode mwheel term/x-win x-win term/common-win x-dnd
touch-screen tool-bar dnd fontset image regexp-opt fringe tabulated-list
replace newcomment text-mode lisp-mode prog-mode register page tab-bar
menu-bar rfn-eshadow isearch easymenu timer select scroll-bar mouse
jit-lock font-lock syntax font-core term/tty-colors frame minibuffer
nadvice seq simple cl-generic indonesian philippine cham georgian
utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean
japanese eucjp-ms cp51932 hebrew greek romanian slovak czech european
ethiopic indian cyrillic chinese composite emoji-zwj charscript charprop
case-table epa-hook jka-cmpr-hook help abbrev obarray oclosure
cl-preloaded button loaddefs theme-loaddefs faces cus-face macroexp
files window text-properties overlay sha1 md5 base64 format env
code-pages mule custom widget keymap hashtable-print-readable backquote
threads dbusbind inotify lcms2 dynamic-setting system-font-setting
font-render-setting cairo gtk x-toolkit xinput2 x multi-tty move-toolbar
make-network-process emacs)

Memory information:
((conses 16 46684 14664) (symbols 48 6036 0) (strings 32 16403 2228)
  (string-bytes 1 485689) (vectors 16 11696)
  (vector-slots 8 190095 12343) (floats 8 32 17) (intervals 56 391 0)
  (buffers 992 12))

bug#66178: 30.0.50; cperl-mode inconsistent hash key fontification

[Harald Jörg]

tags 66178 + wontfix
thanks

Mauro Aranda <maurooaranda@gmail.com> writes:

> emacs -Q
> C-x C-f bug.pl
> M-x cperl-mode
> my %factorial = (
>          0 => 1,
>          zero => 1
>         );
>
> zero is recognized as a string, 0 is not.

This might look surprising, but it is intentional.

zero is a bareword which undergoes hash-key stringification.

The digit 0, on the other hand, is converted to a string according to
Perl's type conversion rules.  That is a different thing: Perl's type
conversion converts all of 0, 000, 0.0, 0E0 to the hash key "0".

Let me expand your example to demonstrate some more cases where the hash
key is (correctly) not fontified as a string:

my %hash = (
    "0"    => 'The string "0"',
    "00"   => 'The string "00"',
    0      => 'A number which is converted to the string "0"',
    00     => 'A number which is converted to the string "0"',
    0.0    => 'A number which is converted to the string "0"',
    0E0    => 'A number which is converted to the string "0"',
    zero   => "A bareword which is stringified",
    zero() => "The function's return value is the key",
    +zero  => "The function's return value is the key",
);

-- 
Cheers,
haj

bug#66178: 30.0.50; cperl-mode inconsistent hash key fontification

[Mauro Aranda]

tags 66178 notabug
close 66178
quit


On 24/9/23 10:44, Harald Jörg wrote:
 > tags 66178 + wontfix
 > thanks
 >
 > Mauro Aranda <maurooaranda@gmail.com> writes:
 >
 >> emacs -Q
 >> C-x C-f bug.pl
 >> M-x cperl-mode
 >> my %factorial = (
 >>           0 => 1,
 >>           zero => 1
 >>          );
 >>
 >> zero is recognized as a string, 0 is not.
 >
 > This might look surprising, but it is intentional.
 >
 > zero is a bareword which undergoes hash-key stringification.
 >
 > The digit 0, on the other hand, is converted to a string according to
 > Perl's type conversion rules.  That is a different thing: Perl's type
 > conversion converts all of 0, 000, 0.0, 0E0 to the hash key "0".
 >
 > Let me expand your example to demonstrate some more cases where the hash
 > key is (correctly) not fontified as a string:
 >
 > my %hash = (
 >      "0"    => 'The string "0"',
 >      "00"   => 'The string "00"',
 >      0      => 'A number which is converted to the string "0"',
 >      00     => 'A number which is converted to the string "0"',
 >      0.0    => 'A number which is converted to the string "0"',
 >      0E0    => 'A number which is converted to the string "0"',
 >      zero   => "A bareword which is stringified",
 >      zero() => "The function's return value is the key",
 >      +zero  => "The function's return value is the key",
 > );

Thank you for the explanation, it makes more sense to me now.  I'm
tagging this one as notabug and closing.