in reply to I fear my code is unreadable

I agree with everyone else that List::Util::max() is the way to go here, but for your readability concerns, the layout of your code can have a huge influence on its readability. A slight restructuring can allow you to loose some of the parens, and make things clearer: 

use constant PADDING => 2;

my $col_width = PADDING + (
    sort { 
        $b <=> $a
    } map { 
        length
    } map {
        ref eq 'ARRAY' ? @$_ : $_   
    } %lists
)[ 0 ]; ## Longest key or value

[download]
Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
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In the absence of evidence, opinion is indistinguishable from prejudice.
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Re^2: I fear my code is unreadable
by Boldra (Curate) on May 06, 2008 at 15:16 UTC
    I like your formatting suggestions, although I'm not sure about " ref eq 'ARRAY' " as being more readable... Unfortunately List::Util and Text::Table aren't available on my target platforms.


    - Boldra
[reply]

      Well, you could go with 

      use constant PADDING => 2;

my $col_width = PADDING + (
    sort {
        $b <=> $a
    } map {
        length
    } keys %list, map {
        @$_
    } values %lists
)[ 0 ]; ## Longest key or value

      [download]

      But in 

      use constant PADDING => 2;

my $col_width = PADDING + (
    sort {
        $b <=> $a
    } map {
        length
    } map {
        ref ? @$_ : $_
    } %lists
)[ 0 ]; ## Longest key or value

      [download]

      The line ref eq 'ARRAY' ? @$_ : $_ just says: if it($_) is a value (array) flatten it to a list, (which you already had in your own version), or if it is a key, pass it through untouched.

      That avoids having to treat the keys and values separately, (and iterate the hash twice to generate them). In doing so it reduces the noise level a little further.

      Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
      "Science is about questioning the status quo. Questioning authority".
      In the absence of evidence, opinion is indistinguishable from prejudice.
[reply]
[d/l]
[select]
        I've adopted it because I saw it saves a loop iteration. The second version there is now actually broken. It works if you add parens, so: ref () ? @$_ : $_


        - Boldra
[reply]
[d/l]

      List::Util and Text::Table aren't available on my target platforms

      What platform is that? List::Util is in the standard library. Everyone has it unless someone has gone to pathological efforts to reduce the size of the perl installation.

[reply]
        Activeperl 5.60 
        
C:\>perl -V
Summary of my perl5 (revision 5 version 6 subversion 0) configuration:
  Platform:
    osname=MSWin32, osvers=4.0, archname=MSWin32-x86-multi-thread
    uname=''
    config_args='undef'
    hint=recommended, useposix=true, d_sigaction=undef
    usethreads=undef use5005threads=undef useithreads=define usemultip
+licity=def
ine
    useperlio=undef d_sfio=undef uselargefiles=undef
    use64bitint=undef use64bitall=undef uselongdouble=undef usesocks=u
+ndef
  Compiler:
    cc='cl', optimize='-O1 -MD -DNDEBUG', gccversion=
    cppflags='-DWIN32'
    ccflags ='-O1 -MD -DNDEBUG -DWIN32 -D_CONSOLE -DNO_STRICT -DHAVE_D
+ES_FCRYPT
 -DPERL_IMPLICIT_CONTEXT -DPERL_IMPLICIT_SYS -DPERL_MSVCRT_READFIX'
    stdchar='char', d_stdstdio=define, usevfork=false
    intsize=4, longsize=4, ptrsize=4, doublesize=8
    d_longlong=undef, longlongsize=8, d_longdbl=define, longdblsize=10
    ivtype='long', ivsize=4, nvtype='double', nvsize=8, Off_t='off_t',
+ lseeksize
=4
    alignbytes=8, usemymalloc=n, prototype=define
  Linker and Libraries:
    ld='link', ldflags ='-nologo -nodefaultlib -release  -libpath:"C:\
+Perl\lib\C
ORE"  -machine:x86'
    libpth="C:\Perl\lib\CORE"
    libs=  oldnames.lib kernel32.lib user32.lib gdi32.lib winspool.lib
+  comdlg32
.lib advapi32.lib shell32.lib ole32.lib oleaut32.lib  netapi32.lib uui
+d.lib wsoc
k32.lib mpr.lib winmm.lib  version.lib odbc32.lib odbccp32.lib msvcrt.
+lib
    libc=msvcrt.lib, so=dll, useshrplib=yes, libperl=perl56.lib
  Dynamic Linking:
    dlsrc=dl_win32.xs, dlext=dll, d_dlsymun=undef, ccdlflags=' '
    cccdlflags=' ', lddlflags='-dll -nologo -nodefaultlib -release  -l
+ibpath:"C:
\Perl\lib\CORE"  -machine:x86'


Characteristics of this binary (from libperl):
  Compile-time options: MULTIPLICITY USE_ITHREADS PERL_IMPLICIT_CONTEX
+T PERL_IMP
LICIT_SYS
  Locally applied patches:
        ActivePerl Build 623
  Built under MSWin32
  Compiled at Dec 15 2000 16:27:07
  @INC:
    C:/Perl/lib
    C:/Perl/site/lib
    .

C:\>perl -MList::Util -e "print """Ok\n""";"
Can't locate List/Util.pm in @INC (@INC contains: C:/Perl/lib C:/Perl/
+site/lib .
).
BEGIN failed--compilation aborted.

C:\>

        [download]


        - Boldra
[reply]
[d/l]

In Section Seekers of Perl Wisdom