### ----------------------------------------------------
### -- P5push
### -- Licenses: Artistic-2.0
### -- Authors: Elizabeth Mattijsen
### -- File: README.md
### ----------------------------------------------------
[![Actions Status](https://github.com/lizmat/P5push/workflows/test/badge.svg)](https://github.com/lizmat/P5push/actions)

NAME
====

Raku port of Perl's push() / pop() built-ins

SYNOPSIS
========

    use P5push;

    my @a = 1,2,3;
    say push @a, 42;  # 4

    say pop;  # pop from @*ARGS, if any

    sub a { dd @_; dd pop; dd @_ }; a 1,2,3;
    [1, 2, 3]
    3
    [1, 2]

DESCRIPTION
===========

This module tries to mimic the behaviour of Perl's `push` and `pop` built-ins as closely as possible in the Raku Programming Language.

ORIGINAL PERL 5 DOCUMENTATION
=============================

    push ARRAY,LIST
    push EXPR,LIST
            Treats ARRAY as a stack by appending the values of LIST to the end
            of ARRAY. The length of ARRAY increases by the length of LIST. Has
            the same effect as

                for $value (LIST) {
                    $ARRAY[++$#ARRAY] = $value;
                }

            but is more efficient. Returns the number of elements in the array
            following the completed "push".

            Starting with Perl 5.14, "push" can take a scalar EXPR, which must
            hold a reference to an unblessed array. The argument will be
            dereferenced automatically. This aspect of "push" is considered
            highly experimental. The exact behaviour may change in a future
            version of Perl.

            To avoid confusing would-be users of your code who are running
            earlier versions of Perl with mysterious syntax errors, put this
            sort of thing at the top of your file to signal that your code
            will work onlyon Perls of a recent vintage:

                use 5.014;  # so push/pop/etc work on scalars (experimental)

    pop ARRAY
    pop EXPR
    pop     Pops and returns the last value of the array, shortening the array
            by one element.

            Returns the undefined value if the array is empty, although this
            may also happen at other times. If ARRAY is omitted, pops the
            @ARGV array in the main program, but the @_ array in subroutines,
            just like "shift".

            Starting with Perl 5.14, "pop" can take a scalar EXPR, which must
            hold a reference to an unblessed array. The argument will be
            dereferenced automatically. This aspect of "pop" is considered
            highly experimental. The exact behaviour may change in a future
            version of Perl.

            To avoid confusing would-be users of your code who are running
            earlier versions of Perl with mysterious syntax errors, put this
            sort of thing at the top of your file to signal that your code
            will work [4monly[m on Perls of a recent vintage:

                use 5.014;  # so push/pop/etc work on scalars (experimental)

PORTING CAVEATS
===============

In future language versions of Raku, it will become impossible to access the `@_` variable of the caller's scope, because it will not have been marked as a dynamic variable. So please consider changing:

    pop;

to:

    pop(@_);

or, using the subroutine as a method syntax:

    @_.&pop;

AUTHOR
======

Elizabeth Mattijsen <liz@raku.rocks>

If you like this module, or what I’m doing more generally, committing to a [small sponsorship](https://github.com/sponsors/lizmat/) would mean a great deal to me!

Source can be located at: https://github.com/lizmat/P5push . Comments and Pull Requests are welcome.

COPYRIGHT AND LICENSE
=====================

Copyright 2018, 2019, 2020, 2021, 2023 Elizabeth Mattijsen

Re-imagined from Perl as part of the CPAN Butterfly Plan.

This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.



