NAME
    NumSeq::Iter - Generate a coderef iterator from a number sequence
    specification (e.g. '1,3,5,...,101')

VERSION
    This document describes version 0.007 of NumSeq::Iter (from Perl
    distribution NumSeq-Iter), released on 2023-11-21.

SYNOPSIS
      use NumSeq::Iter qw(numseq_parse numseq_iter);

      my $iter = numseq_iter('1,3,5,...,13');
      while (my $val = $iter->()) { ... } # 1,3,5,7,9,11,13

      $iter = numseq_iter('1,3,5,...,10');
      while (my $val = $iter->()) { ... } # 1,3,5,7,9

      my $res = numseq_parse('');             # [400, "Parse fail: Please specify one or more number in number sequence: ''"]
      my $res = numseq_parse('1,5,2');        # [200, "OK", {numbers=>[1,5,2], has_ellipsis=>0, type=>'itemized', inc=>undef}]
      my $res = numseq_parse('1,2,3');        # [200, "OK", {numbers=>[1,2,3], has_ellipsis=>0, type=>'itemized', inc=>undef}]
      my $res = numseq_parse('1,2,3,...');    # [200, "OK", {numbers=>[1,2,3], has_ellipsis=>1, type=>'arithmetic', inc=>1, last_number=>undef}]
      my $res = numseq_parse('1,3,9,...');    # [200, "OK", {numbers=>[1,3,9], has_ellipsis=>1, type=>'geometric',  inc=>3, last_number=>undef}]
      my $res = numseq_parse('1,3,5,...,13'); # [200, "OK", {numbers=>[1,3,5], has_ellipsis=>1, type=>'arithmetic', inc=>2, last_number=>13}]
      my $res = numseq_parse('2,3,5,...');    # [200, "OK", {numbers=>[1,3,5], has_ellipsis=>1, type=>'fibonacci'}]
      my $res = numseq_parse('2,3,7,...');    # [400, "Parse fail: Can't determine the pattern from number sequence: 2, 3, 7"]

DESCRIPTION
    This module provides a simple (coderef) iterator which you can call
    repeatedly to get numbers specified in a number sequence specification
    (string). When the numbers are exhausted, the coderef will return undef.
    No class/object involved.

    A number sequence is a comma-separated list of numbers (either integer
    like 1, -2 or decimal number like 1.3, -100.70) with at least one
    number. It can contain an ellipsis (e.g. '1,2,3,...' or '1, 3, 5, ...,
    10').

    When the sequence has an ellipsis, there must be at least three numbers
    before the ellipsis. There can optionally be another number after the
    ellipsis to make the sequence finite; but the last number can also be
    Inf, +Inf, or -Inf. Currently only simple arithmetic sequence ('1,3,5')
    or simple geometric sequence ('2,6,18') is recognized.

FUNCTIONS
  numseq_iter
    Usage:

     $iter = numseq_iter([ \%opts ], $spec); # coderef

    Options:

  numseq_parse
     my $res = numseq_parse([ \%opts ], $spec); # enveloped response

    See "numseq_iter" for list of known options.

HOMEPAGE
    Please visit the project's homepage at
    <https://metacpan.org/release/NumSeq-Iter>.

SOURCE
    Source repository is at <https://github.com/perlancar/perl-NumSeq-Iter>.

SEE ALSO
    Other iterators: IntRange::Iter, Range::Iter

    CLI for this module: seq-numseq (from App::seq::numseq). There's another
    CLI named numseq (from App::numseq), but it is only tangentially
    related.

    Sah::Schemas::NumSeq

    Raku's lazy lists.

AUTHOR
    perlancar <perlancar@cpan.org>

CONTRIBUTING
    To contribute, you can send patches by email/via RT, or send pull
    requests on GitHub.

    Most of the time, you don't need to build the distribution yourself. You
    can simply modify the code, then test via:

     % prove -l

    If you want to build the distribution (e.g. to try to install it locally
    on your system), you can install Dist::Zilla,
    Dist::Zilla::PluginBundle::Author::PERLANCAR,
    Pod::Weaver::PluginBundle::Author::PERLANCAR, and sometimes one or two
    other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps
    required beyond that are considered a bug and can be reported to me.

COPYRIGHT AND LICENSE
    This software is copyright (c) 2023 by perlancar <perlancar@cpan.org>.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.

BUGS
    Please report any bugs or feature requests on the bugtracker website
    <https://rt.cpan.org/Public/Dist/Display.html?Name=NumSeq-Iter>

    When submitting a bug or request, please include a test-file or a patch
    to an existing test-file that illustrates the bug or desired feature.

