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TTY / kurila-1.19_0 / t / op / sort.t 
#!./perl

BEGIN {
    require './test.pl';
}
use warnings;
plan( tests => 52 );

our (@a, @b);

# these shouldn't hang
do {
    no warnings;
    sort { while(1) {}            }, @a;
    sort { while(1) { last; }     }, @a;
    sort { while(0) { last; }     }, @a;

    # Change 26011: Re: A surprising segfault
    map { scalar(sort( @())) }, @( ('')x68);
};

sub Backwards { ($a cmp $b) +< 0 ?? 1 !! ($a cmp $b) +> 0 ?? -1 !! 0 }
sub Backwards_stacked($x, $y) { ($x cmp $y) +< 0 ?? 1 !! ($x cmp $y) +> 0 ?? -1 !! 0 }
sub Backwards_other { ($a cmp $b) +< 0 ?? 1 !! ($a cmp $b) +> 0 ?? -1 !! 0 }

my $upperfirst = ('A' cmp 'a') +< 0;

# Beware: in future this may become hairier because of possible
# collation complications: qw(A a B b) can be sorted at least as
# any of the following
#
#	A a B b
#	A B a b
#	a b A B
#	a A b B
#
# All the above orders make sense.
#
# That said, EBCDIC sorts all small letters first, as opposed
# to ASCII which sorts all big letters first.

our @harry = @('dog','cat','x','Cain','Abel');
our @george = @('gone','chased','yz','punished','Axed');

our $x = join('', sort @harry);
our $expected = $upperfirst ?? 'AbelCaincatdogx' !! 'catdogxAbelCain';

cmp_ok($x,'eq',$expected,'upper first 1');

$x = join('', sort( { Backwards }, @harry));
$expected = $upperfirst ?? 'xdogcatCainAbel' !! 'CainAbelxdogcat';

cmp_ok($x,'eq',$expected,'upper first 2');

$x = join('', sort( { Backwards_stacked($a, $b) }, @harry));
$expected = $upperfirst ?? 'xdogcatCainAbel' !! 'CainAbelxdogcat';

cmp_ok($x,'eq',$expected,'upper first 3');

$x = join('', sort @( < @george, 'to', < @harry));
$expected = $upperfirst ??
    'AbelAxedCaincatchaseddoggonepunishedtoxyz' !!
    'catchaseddoggonepunishedtoxyzAbelAxedCain' ;

cmp_ok($x,'eq',$expected,'upper first 4');
@a = @( () );
@b = reverse @a;
cmp_ok("$(join ' ',@b)",'eq',"",'reverse 1');

@a = @(1);
@b = reverse @a;
cmp_ok("$(join ' ',@b)",'eq',"1",'reverse 2');

@a = @(1,2);
@b = reverse @a;
cmp_ok("$(join ' ',@b)",'eq',"2 1",'reverse 3');

@a = @(1,2,3);
@b = reverse @a;
cmp_ok("$(join ' ',@b)",'eq',"3 2 1",'reverse 4');

@a = @(1,2,3,4);
@b = reverse @a;
cmp_ok("$(join ' ',@b)",'eq',"4 3 2 1",'reverse 5');

@a = @(10,2,3,4);
@b = sort {$a <+> $b;}, @a;
cmp_ok("$(join ' ',@b)",'eq',"2 3 4 10",'sort numeric');

# literals, combinations

@b = sort ( @(4,1,3,2));
cmp_ok("$(join ' ',@b)",'eq','1 2 3 4','just sort');


@b = sort grep { $_ }, @( (4,1,3,2));
cmp_ok("$(join ' ',@b)",'eq','1 2 3 4','grep then sort');


@b = sort map { $_ }, @( (4,1,3,2));
cmp_ok("$(join ' ',@b)",'eq','1 2 3 4','map then sort');


@b = sort reverse ( @(4,1,3,2));
cmp_ok("$(join ' ',@b)",'eq','1 2 3 4','reverse then sort');



sub twoface { no warnings 'redefine'; *twoface = sub { $a <+> $b }; &twoface( < @_ ) }
try { @b = sort \&twoface, @(4,1,3,2) }; die if $^EVAL_ERROR;
cmp_ok("$(join ' ',@b)",'eq','1 2 3 4','redefine sort sub inside the sort sub');

do {
  my $sortsub = \&Backwards;
  my $sortglobr = \*Backwards;
  @b = sort $sortsub, @(4,1,3,2);
  cmp_ok("$(join ' ',@b)",'eq','4 3 2 1','sortname 1');
  @b = sort $sortglobr, @(4,1,3,2);
  cmp_ok("$(join ' ',@b)",'eq','4 3 2 1','sortname 4');
};

our ($sortsub, $sortglob, $sortglobr);
do {
  local $sortsub = \&Backwards;
  local $sortglobr = \*Backwards;
  @b = sort $sortsub, @(4,1,3,2);
  cmp_ok("$(join ' ',@b)",'eq','4 3 2 1','sortname local 1');
  @b = sort $sortglobr, @(4,1,3,2);
  cmp_ok("$(join ' ',@b)",'eq','4 3 2 1','sortname local 4');
};

## exercise sort builtins... ($a <=> $b already tested)
@a = @( 5, 19, 1996, 255, 90 );
@b = sort {
    my $dummy;		# force blockness
    return $b <+> $a
}, @a;
cmp_ok("$(join ' ',@b)",'eq','1996 255 90 19 5','force blockness');

$x = join('', sort { $a cmp $b }, @harry);
$expected = $upperfirst ?? 'AbelCaincatdogx' !! 'catdogxAbelCain';
cmp_ok($x,'eq',$expected,'a cmp b');

$x = join('', sort { $b cmp $a }, @harry);
$expected = $upperfirst ?? 'xdogcatCainAbel' !! 'CainAbelxdogcat';
cmp_ok($x,'eq',$expected,'b cmp a');

do {
    use integer;
    @b = sort { $a <+> $b }, @a;
    cmp_ok("$(join ' ',@b)",'eq','5 19 90 255 1996','integer a <=> b');

    @b = sort { $b <+> $a }, @a;
    cmp_ok("$(join ' ',@b)",'eq','1996 255 90 19 5','integer b <=> a');

    $x = join('', sort { $a cmp $b }, @harry);
    $expected = $upperfirst ?? 'AbelCaincatdogx' !! 'catdogxAbelCain';
    cmp_ok($x,'eq',$expected,'integer a cmp b');

    $x = join('', sort { $b cmp $a }, @harry);
    $expected = $upperfirst ?? 'xdogcatCainAbel' !! 'CainAbelxdogcat';
    cmp_ok($x,'eq',$expected,'integer b cmp a');

};



$x = join('', sort { $a <+> $b }, @( 3, 1, 2));
cmp_ok($x,'eq','123',q(optimized-away comparison block doesn't take any other arguments away with it));

# test sorting in non-main package
package Foo;
@a = @( 5, 19, 1996, 255, 90 );
@b = sort { $b <+> $a }, @a;
main::cmp_ok("$(join ' ',@b)",'eq','1996 255 90 19 5','not in main:: 1');

# check if context for sort arguments is handled right


# test against a reentrancy bug
do {
    package Bar;
    sub compare { $a cmp $b }
    sub reenter { my @force = sort \&compare, qw/a b/ }
};
do {
    my@($def, $init) = @(0, 0);
    @b = sort {
	$def = 1 if defined $Bar::a;
	Bar::reenter() unless $init++;
	$a <+> $b
    }, qw/4 3 1 2/;
    main::cmp_ok("$(join ' ',@b)",'eq','1 2 3 4','reenter 1');

    main::ok(!$def,'reenter 2');
};


do {
    sub routine { @("one", "two") };
    @a = sort(routine(1));
    main::cmp_ok("$(join ' ',@a)",'eq',"one two",'bug id 19991001.003');
};

package main;

# check for in-place optimisation of @a = sort @a
do {
    my ($r1,$r2,@a);
    our @g;
    @g = @(3,2,1); $r1 = \@g[2]; @g = sort @g; $r2 = \@g[0];
    is "$(join ' ',@g)", "1 2 3", "inplace sort of global";

    @a = qw(b a c); $r1 = \@a[1]; @a =sort @a; $r2 = \@a[0];
    is "$(join ' ',@a)", "a b c", "inplace sort of lexical";

    @g = @(2,3,1); $r1 = \@g[1]; @g =sort { $b <+> $a }, @g; $r2 = \@g[0];
    is "$(join ' ',@g)", "3 2 1", "inplace reversed sort of global";

    @g = @(2,3,1);
    $r1 = \@g[1]; @g =sort { $a+<$b??1!!$a+>$b??-1!!0 }, @g; $r2 = \@g[0];
    is "$(join ' ',@g)", "3 2 1", "inplace custom sort of global";

    #  [perl #29790] don't optimise @a = ('a', sort @a) !

    @g = @(3,2,1); @g = @('0', < sort @g);
    is "$(join ' ',@g)", "0 1 2 3", "un-inplace sort of global";
    @g = @(3,2,1); @g = @( <sort( @g),'4');
    is "$(join ' ',@g)", "1 2 3 4", "un-inplace sort of global 2";

    @a = qw(b a c); @a = @('x', < sort @a);
    is "$(join ' ',@a)", "x a b c", "un-inplace sort of lexical";
    @a = qw(b a c); @a = @(( <sort @a), 'x');
    is "$(join ' ',@a)", "a b c x", "un-inplace sort of lexical 2";

    @g = @(2,3,1); @g = @('0', < sort { $b <+> $a }, @g);
    is "$(join ' ',@g)", "0 3 2 1", "un-inplace reversed sort of global";
    @g = @(2,3,1); @g = @(( <sort { $b <+> $a }, @g),'4');
    is "$(join ' ',@g)", "3 2 1 4", "un-inplace reversed sort of global 2";

    @g = @(2,3,1); @g = @('0', < sort { $a+<$b??1!!$a+>$b??-1!!0 }, @g);
    is "$(join ' ',@g)", "0 3 2 1", "un-inplace custom sort of global";
    @g = @(2,3,1); @g = @(( <sort { $a+<$b??1!!$a+>$b??-1!!0 }, @g),'4');
    is "$(join ' ',@g)", "3 2 1 4", "un-inplace custom sort of global 2";
};

# test that optimized {$b cmp $a} and {$b <=> $a} remain stable
# (new in 5.9) without overloading
do { no warnings;
my @input = qw/5first 6first 5second 6second/;
@b = sort { $b <+> $a }, @input;
is "$(join ' ',@b)" , "6first 6second 5first 5second", "optimized \{$b <=> $a\} without overloading" ;
@input =sort {$b <+> $a}, @input;
is "$(join ' ',@input)" , "6first 6second 5first 5second","inline optimized \{$b <=> $a\} without overloading" ;
};;

my @output;

do {
    my $failed = 0;

    sub rec {
	my $n = shift;
	if (!defined($n)) {  # No arg means we're being called by sort()
	    return 1;
	}
	if ($n+<5) { rec($n+1); }
	else { @(...) =  sort \&rec, @(1,2); }

	$failed = 1 if !defined $n;
    }

    rec(1);
    main::ok(!$failed, "sort from active sub");
};

# $a and $b are set in the package the sort() is called from,
# *not* the package the sort sub is in. This is longstanding
# de facto behaviour that shouldn't be broken.
package main;
my $answer = "good";
@(...) =  sort \&OtherPack::foo, @(1,2,3,4);

do {
    package OtherPack;
    no warnings 'once';
    sub foo {
	$answer = "something was unexpectedly defined or undefined" if
	defined($a) || defined($b) || !defined($main::a) || !defined($main::b);
	$main::a <+> $main::b;
    }
};

main::cmp_ok($answer,'eq','good','sort subr called from other package');


# Bug 36430 - sort called in package2 while a
# sort in package1 is active should set $package2::a/b.

$answer = "good";
my @list = sort { A::min(< @$a) <+> A::min(< @$b) },
 @(  \@(3, 1, 5), \@(2, 4), \@(0));

main::cmp_ok($answer,'eq','good','bug 36430');

package A;
sub min {
  my @list = sort {
    $answer = '$a and/or $b are not defined ' if !defined($a) || !defined($b);
    $a <+> $b;
  }, @_;
  @list[0];
}

# Sorting shouldn't increase the refcount of a sub
sub foo {(1+$a) <+> (1+$b)}
my $refcnt = &Internals::SvREFCNT(\&foo);
@output = sort @( foo 3,7,9);
main::is($refcnt, &Internals::SvREFCNT(\&foo), "sort sub refcnt");
my $fail_msg = q(Modification of a read-only value attempted);
# Sorting a read-only array in-place shouldn't be allowed
my @readonly =1..10;
Internals::SvREADONLY(\@readonly, 1);
try { @readonly = sort @readonly; };
main::cmp_ok(substr($^EVAL_ERROR->{?description},0,length($fail_msg)),'eq',$fail_msg,'in-place sort of read-only array');




# Using return() should be okay even in a deeper context
@b = sort {while (1) {return  $a <+> $b} }, 1..10;
main::is("$(join ' ',@b)", "1 2 3 4 5 6 7 8 9 10", "return within loop");

# Using return() should be okay even if there are other items
# on the stack at the time.
@b = sort {$_ = ($a<+>$b) + do{return $b<+> $a}}, 1..10;
main::is("$(join ' ',@b)", "10 9 8 7 6 5 4 3 2 1", "return with SVs on stack");