NAME

Seq - A lazy sequence implementation

SYNOPSIS

This is a lazy sequence implementation. C# has LINQ, Java has Stream, F# has Seq. Perl also has Seq. Some useful stuff implemented, but currently lacking Documentation. Look at test scripts so far.

    use v5.36;
    use Seq;

    # Fibonacci Generator
    my $fib =
        Seq->concat(
            Seq->wrap(1,1),
            Seq->unfold([1,1], sub($state) {
                my $next = $state->[0] + $state->[1];
                return $next, [$state->[1],$next];
            })
        );

    # prints: 1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597 2584 4181 6765
    $fib->take(20)->iter(sub($x) {
        say $x;
    });

    # Represents all possible combinations
    # [[clubs => 7], [clubs => 8], [clubs => 9], ...]
    my $cards =
        Seq::cartesian(
            Seq->wrap(qw/clubs spades hearts diamond/),
            Seq->wrap(qw/7 8 9 10 B D K A/)
        );

    use Path::Tiny qw(path);
    # get the maximum id from test-files so far
    my $maximum_id =
        Seq
        ->wrap(   path('t')->children )
        ->map(    sub($x) { $x->basename })
        ->choose( sub($x) { $x =~ m/\A(\d+) .* \.t\z/xms ? $1 : undef } )
        ->max;

EXPORT

This modules does not export anything by default. But you can request the following functions: id, fst, snd, key, assign

CONSTRUCTORS

This module uses functional-programming as the main paradigm. Functions are divided into constructors that create *Sequences* and functions that operate on Sequences (Methods). They are called methods for convenience, but no object-orientation is involved. Perls OO capabilities are only used as a chaning mechanism.

Constructors must be called with the Package name. Functions that operate on Sequences can either be called as a method or directly from the Package.

    my $range =
        Seq
        ->wrap(1,2,3)
        ->append(Seq->wrap(4,5,6));

or

    my $range =
        Seq::to_array(
            Seq::append(
                Seq->wrap(1,2,3),
                Seq->wrap(4,5,6),
            )
        );

$seq = Seq->empty()

Returns an empty sequence. Useful as an initial state or as a starting point.

    Seq->empty->append( $another_seq )

$seq = Seq->range($start, $stop)

Returns a sequence from $start to $stop. Range can also be backwards. $start and $stop are inclusive.

    Seq->range(1, 5); # 1,2,3,4,5
    Seq->range(5, 1); # 5,4,3,2,1
    Seq->range(1, 1); # 1

$seq = Seq->wrap(...)

Just takes whatever you pass it to, and puts it in a sequence. This should be your primarily way to create a sequence with values.

    Seq->wrap(qw/Hello World/); # "Hello", "World"
    Seq->wrap(1 .. 10);         # AVOID this, use Seq->range(1, 10) instead.
    Seq->wrap(@array);

$seq = Seq->concat(@sequences)

Takes multiple *Sequences* and returns a single flattened sequence.

    # 1, 2, 3, 4, 5, 5, 4, 3, 2, 1
    Seq->concat(
        Seq->range(1, 5),
        Seq->range(5, 1),
    );

Github

Development project is on Github. https://github.com/DavidRaab/Seq

BUGS

Please report any bugs or feature requests to bug-seq at rt.cpan.org, or through the web interface at https://rt.cpan.org/NoAuth/ReportBug.html?Queue=Seq. I will be notified, and then you'll automatically be notified of progress on your bug as I make changes.

SUPPORT

You can find documentation for this module with the perldoc command.

    perldoc Seq

You can also look for information at:

AUTHOR

David Raab, <davidraab83 at gmail.com>

LICENSE AND COPYRIGHT

This software is Copyright (c) 2023 by David Raab.

This is free software, licensed under:

  The MIT (X11) License

cpanm Seq

perl -MCPAN -e shell
install Seq