# This tests the behavior of sort() under the different 'use sort' forms.
# Algorithm by John P. Linderman.
-use strict;
-use warnings;
-
my ($BigWidth, $BigEnough, $RootWidth, $ItemFormat, @TestSizes, $WellSoaked);
BEGIN {
}
}
+use strict;
+use warnings;
+
use Test::More tests => @TestSizes * 2 # sort() tests
- * 4 # number of pragmas to test
+ * 6 # number of pragmas to test
+ 1 # extra test for qsort instability
- + 3; # tests for sort::current
+ + 3 # tests for sort::current
+ + 3; # tests for "defaults" and "no sort"
# Generate array of specified size for testing sort.
#
sub checkorder {
my $aref = shift;
my $status = ''; # so far, so good
- my $i;
+ my ($i, $disorder);
for ($i = 0; $i < $#$aref; ++$i) {
- next if ($aref->[$i] lt $aref->[$i+1]);
- $status = (substr($aref->[$i], 0, $RootWidth) eq
- substr($aref->[$i+1], 0, $RootWidth)) ?
- "Instability" : "Disorder";
- $status .= " at element $i between $aref->[$i] and $aref->[$i+1]";
- last;
+ # Equality shouldn't happen, but catch it in the contents check
+ next if ($aref->[$i] le $aref->[$i+1]);
+ $disorder = (substr($aref->[$i], 0, $RootWidth) eq
+ substr($aref->[$i+1], 0, $RootWidth)) ?
+ "Instability" : "Disorder";
+ # Keep checking if merely unstable... disorder is much worse.
+ $status =
+ "$disorder at element $i between $aref->[$i] and $aref->[$i+1]";
+ last unless ($disorder eq "Instability");
}
return $status;
}
# Test sort on arrays of various sizes (set up in @TestSizes)
sub main {
- my ($expect_unstable) = @_;
+ my ($dothesort, $expect_unstable) = @_;
my ($ts, $unsorted, @sorted, $status);
my $unstable_num = 0;
# Sort only on item portion of each element.
# There will typically be many repeated items,
# and their order had better be preserved.
- @sorted = sort { substr($a, 0, $RootWidth)
+ @sorted = $dothesort->(sub { substr($a, 0, $RootWidth)
cmp
- substr($b, 0, $RootWidth) } @$unsorted;
+ substr($b, 0, $RootWidth) }, $unsorted);
$status = checkorder(\@sorted);
# Put the items back into the original order.
# The contents of the arrays had better be identical.
++$unstable_num;
}
is($status, '', "order ok for size $ts");
- @sorted = sort { substr($a, $RootWidth)
+ @sorted = $dothesort->(sub { substr($a, $RootWidth)
cmp
- substr($b, $RootWidth) } @sorted;
+ substr($b, $RootWidth) }, \@sorted);
$status = checkequal(\@sorted, $unsorted);
is($status, '', "contents ok for size $ts");
}
+ # If the following test (#58) fails, see the comments in pp_sort.c
+ # for Perl_sortsv().
if ($expect_unstable) {
ok($unstable_num > 0, 'Instability ok');
}
}
# Test with no pragma still loaded -- stability expected (this is a mergesort)
-main(0);
-
-# XXX We're using this eval "..." trick to force recompilation,
-# to ensure that the correct pragma is enabled when main() is run.
-# Currently 'use sort' modifies $^H{SORT} at compile-time, but
-# pp_sort() fetches its value at run-time : thus the lexical scoping
-# of %^H is of no utility.
-# The order of those evals is important.
+main(sub { sort {&{$_[0]}} @{$_[1]} }, 0);
-eval q{
+{
use sort qw(_qsort);
- is(sort::current(), 'quicksort', 'sort::current for _qsort');
- main(1);
-};
-die $@ if $@;
+ my $sort_current; BEGIN { $sort_current = sort::current(); }
+ is($sort_current, 'quicksort', 'sort::current for _qsort');
+ main(sub { sort {&{$_[0]}} @{$_[1]} }, 1);
+}
-eval q{
+{
use sort qw(_mergesort);
- is(sort::current(), 'mergesort', 'sort::current for _mergesort');
- main(0);
-};
-die $@ if $@;
+ my $sort_current; BEGIN { $sort_current = sort::current(); }
+ is($sort_current, 'mergesort', 'sort::current for _mergesort');
+ main(sub { sort {&{$_[0]}} @{$_[1]} }, 0);
+}
-eval q{
+{
use sort qw(_qsort stable);
- is(sort::current(), 'quicksort stable', 'sort::current for _qsort stable');
- main(0);
-};
-die $@ if $@;
+ my $sort_current; BEGIN { $sort_current = sort::current(); }
+ is($sort_current, 'quicksort stable', 'sort::current for _qsort stable');
+ main(sub { sort {&{$_[0]}} @{$_[1]} }, 0);
+}
+
+# Tests added to check "defaults" subpragma, and "no sort"
+
+{
+ use sort qw(_qsort stable);
+ no sort qw(_qsort);
+ my $sort_current; BEGIN { $sort_current = sort::current(); }
+ is($sort_current, 'stable', 'sort::current after no _qsort');
+ main(sub { sort {&{$_[0]}} @{$_[1]} }, 0);
+}
+
+{
+ use sort qw(defaults _qsort);
+ my $sort_current; BEGIN { $sort_current = sort::current(); }
+ is($sort_current, 'quicksort', 'sort::current after defaults _qsort');
+ # Not expected to be stable, so don't test for stability here
+}
+
+{
+ use sort qw(defaults stable);
+ my $sort_current; BEGIN { $sort_current = sort::current(); }
+ is($sort_current, 'stable', 'sort::current after defaults stable');
+ main(sub { sort {&{$_[0]}} @{$_[1]} }, 0);
+}