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lib/Acme/Sort/Bozo.pm  view on Meta::CPAN

}



# Internal use, not exported.  Verifies order based on $compare->().
sub is_ordered {
    my ( $compare, $listref ) = @_;
    ref( $compare ) =~ /CODE/ 
        or croak "is_ordered() expects a coderef as first arg.";
    ref( $listref ) =~ /ARRAY/
        or croak "is_ordered() expects an arrayref as second arg.";
    foreach( 0 .. $#{$listref} - 1 ) {
        return 0 
            if $compare->( $listref->[ $_ ], $listref->[ $_ + 1 ] ) > 0;
    }
    return 1;
}

# Internal use, not exported.  Simply swaps two random elements.  The elements
# are guaranteed to be distinct.
sub swap {
    my $listref = shift;
    my $elements = @{$listref};
    my $first = int( rand( $elements ) );
    my $second;
    do{ $second = int( rand( $elements ) ); } until $second != $first;
#    ( $listref->[$first], $listref->[$second] ) = ( $listref->[$second], $listref->[$first] );
    @{$listref}[$first, $second] = @{$listref}[$second, $first];
    return $listref;
}


# Default compare() is ascending standard string comparison order.
sub compare {
    croak "compare() requires two args."
        unless scalar @_ == 2;
    return $_[0] cmp $_[1];
}

t/00-load.t  view on Meta::CPAN

    "is_ordered() throws exception when not handed a coderef as first param."
);

undef $caught;
try {
    Acme::Sort::Bozo::is_ordered( $compare, qw/ A B C D E / );
} catch { $caught = $_ };
like(
    $caught,
    qr/expects an arrayref/,
    "is_ordered() throws an exception when not handed an arrayref as second param."
);

note "Testing Acme::Sort::Bozo::swap()";
my $listref = [qw/ A B C D E / ];
my $orig = join '', @{$listref};
my $new = join '', @{ Acme::Sort::Bozo::swap( $listref ) };
isnt( $new, $orig, "Swap successfully swapped two elements." );