source: trunk/essentials/dev-lang/perl/t/op/local.t

#!./perl

BEGIN {
    chdir 't' if -d 't';
    require './test.pl';
}
plan tests => 81;

my $list_assignment_supported = 1;

#mg.c says list assignment not supported on VMS, EPOC, and SYMBIAN.
$list_assignment_supported = 0 if ($^O eq 'VMS');


sub foo {
    local($a, $b) = @_;
    local($c, $d);
    $c = "c 3";
    $d = "d 4";
    { local($a,$c) = ("a 9", "c 10"); ($x, $y) = ($a, $c); }
    is($a, "a 1");
    is($b, "b 2");
    $c, $d;
}

$a = "a 5";
$b = "b 6";
$c = "c 7";
$d = "d 8";

my @res;
@res =  &foo("a 1","b 2");
is($res[0], "c 3");
is($res[1], "d 4");

is($a, "a 5");
is($b, "b 6");
is($c, "c 7");
is($d, "d 8");
is($x, "a 9");
is($y, "c 10");

# same thing, only with arrays and associative arrays

sub foo2 {
    local($a, @b) = @_;
    local(@c, %d);
    @c = "c 3";
    $d{''} = "d 4";
    { local($a,@c) = ("a 19", "c 20"); ($x, $y) = ($a, @c); }
    is($a, "a 1");
    is("@b", "b 2");
    $c[0], $d{''};
}

$a = "a 5";
@b = "b 6";
@c = "c 7";
$d{''} = "d 8";

@res = &foo2("a 1","b 2");
is($res[0], "c 3");
is($res[1], "d 4");

is($a, "a 5");
is("@b", "b 6");
is($c[0], "c 7");
is($d{''}, "d 8");
is($x, "a 19");
is($y, "c 20");


eval 'local($$e)';
like($@, qr/Can't localize through a reference/);

eval '$e = []; local(@$e)';
like($@, qr/Can't localize through a reference/);

eval '$e = {}; local(%$e)';
like($@, qr/Can't localize through a reference/);

# Array and hash elements

@a = ('a', 'b', 'c');
{
    local($a[1]) = 'foo';
    local($a[2]) = $a[2];
    is($a[1], 'foo');
    is($a[2], 'c');
    undef @a;
}
is($a[1], 'b');
is($a[2], 'c');
ok(!defined $a[0]);

@a = ('a', 'b', 'c');
{
    local($a[1]) = "X";
    shift @a;
}
is($a[0].$a[1], "Xb");
{
    my $d = "@a";
    local @a = @a;
    is("@a", $d);
}

%h = ('a' => 1, 'b' => 2, 'c' => 3);
{
    local($h{'a'}) = 'foo';
    local($h{'b'}) = $h{'b'};
    is($h{'a'}, 'foo');
    is($h{'b'}, 2);
    local($h{'c'});
    delete $h{'c'};
}
is($h{'a'}, 1);
is($h{'b'}, 2);
{
    my $d = join("\n", map { "$_=>$h{$_}" } sort keys %h);
    local %h = %h;
    is(join("\n", map { "$_=>$h{$_}" } sort keys %h), $d);
}
is($h{'c'}, 3);

# check for scope leakage
$a = 'outer';
if (1) { local $a = 'inner' }
is($a, 'outer');

# see if localization works when scope unwinds
local $m = 5;
eval {
    for $m (6) {
        local $m = 7;
        die "bye";
    }
};
is($m, 5);

# see if localization works on tied arrays
{
    package TA;
    sub TIEARRAY { bless [], $_[0] }
    sub STORE { print "# STORE [@_]\n"; $_[0]->[$_[1]] = $_[2] }
    sub FETCH { my $v = $_[0]->[$_[1]]; print "# FETCH [@_=$v]\n"; $v }
    sub CLEAR { print "# CLEAR [@_]\n"; @{$_[0]} = (); }
    sub FETCHSIZE { scalar(@{$_[0]}) }
    sub SHIFT { shift (@{$_[0]}) }
    sub EXTEND {}
}

tie @a, 'TA';
@a = ('a', 'b', 'c');
{
    local($a[1]) = 'foo';
    local($a[2]) = $a[2];
    is($a[1], 'foo');
    is($a[2], 'c');
    @a = ();
}
is($a[1], 'b');
is($a[2], 'c');
ok(!defined $a[0]);
{
    my $d = "@a";
    local @a = @a;
    is("@a", $d);
}

{
    package TH;
    sub TIEHASH { bless {}, $_[0] }
    sub STORE { print "# STORE [@_]\n"; $_[0]->{$_[1]} = $_[2] }
    sub FETCH { my $v = $_[0]->{$_[1]}; print "# FETCH [@_=$v]\n"; $v }
    sub EXISTS { print "# EXISTS [@_]\n"; exists $_[0]->{$_[1]}; }
    sub DELETE { print "# DELETE [@_]\n"; delete $_[0]->{$_[1]}; }
    sub CLEAR { print "# CLEAR [@_]\n"; %{$_[0]} = (); }
    sub FIRSTKEY { print "# FIRSTKEY [@_]\n"; keys %{$_[0]}; each %{$_[0]} }
    sub NEXTKEY { print "# NEXTKEY [@_]\n"; each %{$_[0]} }
}

# see if localization works on tied hashes
tie %h, 'TH';
%h = ('a' => 1, 'b' => 2, 'c' => 3);

{
    local($h{'a'}) = 'foo';
    local($h{'b'}) = $h{'b'};
    local($h{'y'});
    local($h{'z'}) = 33;
    is($h{'a'}, 'foo');
    is($h{'b'}, 2);
    local($h{'c'});
    delete $h{'c'};
}
is($h{'a'}, 1);
is($h{'b'}, 2);
is($h{'c'}, 3);
# local() should preserve the existenceness of tied hash elements
ok(! exists $h{'y'});
ok(! exists $h{'z'});
TODO: {
    todo_skip("Localize entire tied hash");
    my $d = join("\n", map { "$_=>$h{$_}" } sort keys %h);
    local %h = %h;
    is(join("\n", map { "$_=>$h{$_}" } sort keys %h), $d);
}

@a = ('a', 'b', 'c');
{
    local($a[1]) = "X";
    shift @a;
}
is($a[0].$a[1], "Xb");

# now try the same for %SIG

$SIG{TERM} = 'foo';
$SIG{INT} = \&foo;
$SIG{__WARN__} = $SIG{INT};
{
    local($SIG{TERM}) = $SIG{TERM};
    local($SIG{INT}) = $SIG{INT};
    local($SIG{__WARN__}) = $SIG{__WARN__};
    is($SIG{TERM}, 'main::foo');
    is($SIG{INT}, \&foo);
    is($SIG{__WARN__}, \&foo);
    local($SIG{INT});
    delete $SIG{__WARN__};
}
is($SIG{TERM}, 'main::foo');
is($SIG{INT}, \&foo);
is($SIG{__WARN__}, \&foo);
{
    my $d = join("\n", map { "$_=>$SIG{$_}" } sort keys %SIG);
    local %SIG = %SIG;
    is(join("\n", map { "$_=>$SIG{$_}" } sort keys %SIG), $d);
}

# and for %ENV

$ENV{_X_} = 'a';
$ENV{_Y_} = 'b';
$ENV{_Z_} = 'c';
{
    local($ENV{_A_});
    local($ENV{_B_}) = 'foo';
    local($ENV{_X_}) = 'foo';
    local($ENV{_Y_}) = $ENV{_Y_};
    is($ENV{_X_}, 'foo');
    is($ENV{_Y_}, 'b');
    local($ENV{_Z_});
    delete $ENV{_Z_};
}
is($ENV{_X_}, 'a');
is($ENV{_Y_}, 'b');
is($ENV{_Z_}, 'c');
# local() should preserve the existenceness of %ENV elements
ok(! exists $ENV{_A_});
ok(! exists $ENV{_B_});

SKIP: {
    skip("Can't make list assignment to \%ENV on this system")
        unless $list_assignment_supported;
    my $d = join("\n", map { "$_=>$ENV{$_}" } sort keys %ENV);
    local %ENV = %ENV;
    is(join("\n", map { "$_=>$ENV{$_}" } sort keys %ENV), $d);
}

# does implicit localization in foreach skip magic?

$_ = "o 0,o 1,";
my $iter = 0;
while (/(o.+?),/gc) {
    is($1, "o $iter");
    foreach (1..1) { $iter++ }
    if ($iter > 2) { fail("endless loop"); last; }
}

{
    package UnderScore;
    sub TIESCALAR { bless \my $self, shift }
    sub FETCH { die "read  \$_ forbidden" }
    sub STORE { die "write \$_ forbidden" }
    tie $_, __PACKAGE__;
    my @tests = (
        "Nesting"     => sub { print '#'; for (1..3) { print }
                               print "\n" },                    1,
        "Reading"     => sub { print },                         0,
        "Matching"    => sub { $x = /badness/ },                0,
        "Concat"      => sub { $_ .= "a" },                     0,
        "Chop"        => sub { chop },                          0,
        "Filetest"    => sub { -x },                            0,
        "Assignment"  => sub { $_ = "Bad" },                    0,
        # XXX whether next one should fail is debatable
        "Local \$_"   => sub { local $_  = 'ok?'; print },      0,
        "for local"   => sub { for("#ok?\n"){ print } },        1,
    );
    while ( ($name, $code, $ok) = splice(@tests, 0, 3) ) {
        eval { &$code };
        main::ok(($ok xor $@), "Underscore '$name'");
    }
    untie $_;
}

{
    # BUG 20001205.22
    my %x;
    $x{a} = 1;
    { local $x{b} = 1; }
    ok(! exists $x{b});
    { local @x{c,d,e}; }
    ok(! exists $x{c});
}