NAME

Jo::Util - Loose collection of some tools

VERSION

This document describes Jo::Util version 0.03

SYNOPSIS

Import the desired functions and use them as described for each individual one.

    use Jo::Util 'func_name';

Imported names may be modified like:

    use Jo::Util func_name => {-as => 'other_name'}

See Exporter::Tiny::Manual::Importing for details.

EXPORT

Functions that may be exported by this modure are:

• aref
• genlist
• splitdata
• stopmatch
• narray

SUBROUTINES

aref LIST

Returns a reference to an array consisting of the elements of LIST or undef if LIST is empty.

Examples

    $pair = aref each %h;
    print "$pair->[0] => $pair->[1]\n" if $pair;

genlist BLOCK

Calls given BLOCK repeatedly in list context and collects all returned items into a single list. Stops when BLOCK returns undef or an empty list and returns the list of gathered items.

Examples

Something similar to “pairs” in List::Util:

    @pairs = genlist {aref each %h};

Create a list from a for(;;)-like construct:

    use feature 'state';
    
    @forlist = genlist {state $x = 1; my $y = $x;
            $x *= 2; $y <= 2048 ? $y : undef};

splitdata

Split the data from the DATA file handle into several parts, separated by lines of the form

    __NAME_IN_UPPERCASE__

Returns a hash with the names as keys and corresponding file handles to read the data from as values.

When called with the parameter “-create”, split_data will create file handles named like the parts in the caller’s namespace.

The first data part is always named “DATA”.

Examples

use Jo::Util 'split_data';

my %data = splitdata -create;

while (<DATA>) {
    # process line from DATA
}

    # or

while (readline $data{EXT}) {
    # process line from EXT
}

__DATA__
data 1
data 2
__EXT__
ext 1
ext 2

There is not really a need for this function, as almost the same can be accomplished using:

    open EXT, '<', \(<<'EOF');
    ext 1
    ext 2
    EOF

stopmatch REGEX

Returns a regular expression that matches everything up to but not including the given REGEX. This is something similar to

    [^...]

where “not to be matched” isn’t from a given set of characters, but by the given regular expression.

Examples

Match everything up to a word in capital letters

    $re = stopmatch qr{\b[A-Z]+\b};
    $found = /($re)/ for 'Some text up to THIS word';
    # $found is 'Some text up to '

narray subref d1 … dn

Returns a reference to a n-dimensional array.

subref is a reference to a sub expecing n arguments and returning the disired value for $a->[x1]...[xn]. and di is the size in the i-th dimension.

Examples

Create simple array ref of 5 elements:

    $ar = narray {$_[0]} 5;
    # $ar = [0, 1, 2, 3, 4]

Create 3x3 matrix:

    $m = narray {3 * $_[0] + $[1]} 3, 3;
    # $m = [[0, 1, 2], [3, 4, 5], [6, 7, 8]]

SEE ALSO

Exporter::Tiny::Manual::Importing

AUTHOR

Jörg Sommrey, <28217714+jo-37 at users.noreply.github.com>

LICENSE AND COPYRIGHT

Copyright 2020 Jörg Sommrey.

This program is free software; you can redistribute it and/or modify it under the terms of the the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

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