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

VERSION
    This document describes version 0.002 of NumSeq::Iter (from Perl
    distribution NumSeq-Iter), released on 2021-07-17.

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

      my $res = numseq_parse(''); # [400, "Parse fail: Please specify one or more number in number sequence"]
      my $res = numseq_parse('1,3,5');        # [200, "OK", {numbers=>[1,2,3], has_ellipsis=>0, type=>'arithmetic', inc=>2}]
      my $res = numseq_parse('1,3,9,...');    # [200, "OK", {numbers=>[1,3,9], has_ellipsis=>1, last_number=>undef, type=>'geometric', inc=>3}]
      my $res = numseq_parse('1,3,5,...,10'); # [200, "OK", {numbers=>[1,2,3], has_ellipsis=>1, last_number=>10, type=>'arithmetic', inc=>2}]

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>.

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.

SEE ALSO
    IntRange::Iter, Range::Iter

    Raku's lazy lists.

AUTHOR
    perlancar <perlancar@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2021 by 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.