Okay. Since a couple of people have asked about a runnable testcase, I've hacked together a version that tests the code on a static string that gets chopped up and fed to pp(), rather than generated during the recursive traversal of a datastructure as in the real code.
There are two version here. The original, very messy but working version, and a slightly cleaned up--thanks to dragonchild and hv--that now exhibits an edgecase bug that I am trying to track down.
To see the introduced bug, download both as (say) test1.pl and test2.pl and run them both with a command line parameter of '403'. (you'll need a console capable of handling 405 chars wide or redirect to a file and view the output in an editor that doesn't wrap).
P:\test>test1 403 ## Working
[ 0:42:06.40] P:\test>test1 403
{
a => [ SCALAR(0x18bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
b => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
c => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
d => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
e => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
f => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
g => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
h => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
i => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
j => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [
+1, 2
}
P:\test>test2 403 ## Broken
{
a => [ SCALAR(0x18bb45c), { a => b, c => d, e => f,
b => [
SELFREF(018bb45c),
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
],
c => [ SELFREF(018bb45c), { a => b, c => d, e => f,
d => [
SELFREF(018bb45c),
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
],
e => [ SELFREF(018bb45c), { a => b, c => d, e => f,
f => [
SELFREF(018bb45c),
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
{ a => b, c => d, e => f, g => h, },
[ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
],
g => [ SELFREF(018bb45c), { a => b, c => d, e => f,
h => [ SELFREF(018bb45c), { a => b, c => d, e => f,
i => [ SELFREF(018bb45c), { a => b, c => d, e => f,
j => [ SELFREF(018bb45c), { a => b, c => d, e => f,
}
Another iteresting transition point with the supplied data occurs with paramters of 35 & 36. Note the differences in the formatting of the values for the 'f' and 'i' keys.
#! perl -slw
use strict;
use List::Util qw[ min ];
$|=1;
## Original working code.
my $data = <DATA>;
my $depth = 0;
my $indent = ' ';
sub indexBal {
my( $string, $lookFor, $limit ) = @_;
my $nesting = 0;
for( my( $position, $char ) = ( 0, substr $string, 0, 1 );
$position < min( length( $string ) , $limit );
$char = substr $string, ++$position, 1
) {
$nesting++ if $char =~ m/[\[\{]/;
$nesting-- if $char =~ m/[\]\}]/;
die 'Unbalanced' if $nesting < 0;
return $position if $char eq $lookFor and $nesting == 0
}
return;
}
my $string = '';
sub pp {
my( $s, $max_width, $EOS ) = @_;
$string .= $s;
# warn "\npp:'$string'\n";
while( length( $string ) > $max_width or $EOS and length( $string
+) ) {
my $flag;
$string =~ m/([\[\{\]\},])/g and my( $position, $first ) = ( p
+os $string, $1 );
return unless defined $position;
if( defined $first and $first ne ',' ) {
if( $first =~ m/[\]\}]/ ) {
$position++;
$depth--;
}
else {
my $position2 = indexBal $string, $first eq '[' ? ']'
+: '}', $max_width;
if( defined $position2 ) {
$position = $position2 + 2;
}
else {
$flag = 1;
}
}
}
print $indent x $depth, substr( $string, 0, $position );# <STD
+IN>;
$string =~ s[^.{$position}\s*][];
$depth++ if $flag;
}
}
## Test harness only below here
my $width = $ARGV[ 0 ]||100;
$indent = $ARGV[ 1 ] if @ARGV == 2;
while( length $data ) {
my $p = 1+rindex( $data, ',', $width+rand( 50 ) )||length $data;
my $sub = substr( $data, 0, $p, '' );
pp( $sub, $width, !length $data );
}
__DATA__
{ a => [ SCALAR(0x18bb45c), { a => b, c => d, e => f, g => h, }, [ 1,
+ 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }
+, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g =>
+ h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f
+, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d,
+e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], ], b => [ S
+ELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4,
+ 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2,
+ 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [
+ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h,
+ }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g
+ => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], ], c => [ SELFREF(01
+8bb45c), { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7,
+ 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5,
+ 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3,
+ 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1,
+ 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }
+, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], ], d => [ SELFREF(018bb45c),
+{ a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
+, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8,
+ 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6,
+ 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4,
+ 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2,
+ 3, 4, 5, 6, 7, 8, 9, 10, ], ], e => [ SELFREF(018bb45c), { a => b,
+ c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a
+ => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9,
+ 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7,
+ 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5,
+ 6, 7, 8, 9, 10, ], ], f => [ SELFREF(018bb45c), { a => b, c => d,
+e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c
+=> d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a =>
+ b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ],
+{ a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10
+, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8,
+ 9, 10, ], ], g => [ SELFREF(018bb45c), { a => b, c => d, e => f, g
+ => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e =
+> f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c =>
+d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b,
+ c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a
+ => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,
+], ], h => [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }
+, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g =>
+ h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f
+, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d,
+e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c
+=> d, e => f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], ], i
+=> [ SELFREF(018bb45c), { a => b, c => d, e => f, g => h, }, [ 1, 2,
+ 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [
+ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h,
+ }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g
+ => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e =
+> f, g => h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], ], j => [ SELF
+REF(018bb45c), { a => b, c => d, e => f, g => h, }, [ 1, 2, 3, 4, 5,
+ 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1, 2, 3,
+ 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }, [ 1,
+ 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g => h, }
+, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], { a => b, c => d, e => f, g =>
+ h, }, [ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ], ], }