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libdata-optlist-perl 0.103-2
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NAME
    Data::OptList - parse and validate simple name/value option pairs

VERSION
    version 0.102

      $Id: /my/cs/projects/Data-OptList/trunk/lib/Data/OptList.pm 31979 2007-07-05T02:17:36.805594Z rjbs  $

SYNOPSIS
      use Data::OptList;

      my $options = Data::Optlist::mkopt([
        qw(key1 key2 key3 key4),
        key5 => { ... },
        key6 => [ ... ],
        key7 => sub { ... },
        key8 => { ... },
        key8 => [ ... ],
      ]);

    ...is the same thing, more or less, as:

      my $options = [
        [ key1 => undef,        ],
        [ key2 => undef,        ],
        [ key3 => undef,        ],
        [ key4 => undef,        ],
        [ key5 => { ... },      ],
        [ key6 => [ ... ],      ],
        [ key7 => sub { ... },  ],
        [ key8 => { ... },      ],
        [ key8 => [ ... ],      ],
      ]);

DESCRIPTION
    Hashes are great for storing named data, but if you want more than one
    entry for a name, you have to use a list of pairs. Even then, this is
    really boring to write:

      $values = [
        foo => undef,
        bar => undef,
        baz => undef,
        xyz => { ... },
      ];

    Just look at all those undefs! Don't worry, we can get rid of those:

      $values = [
        map { $_ => undef } qw(foo bar baz),
        xyz => { ... },
      ];

    Aaaauuugh! We've saved a little typing, but now it requires thought to
    read, and thinking is even worse than typing.

    With Data::OptList, you can do this instead:

      $values = Data::OptList::mkopt([
        qw(foo bar baz),
        xyz => { ... },
      ]);

    This works by assuming that any defined scalar is a name and any
    reference following a name is its value.

FUNCTIONS
  mkopt
      my $opt_list = Data::OptList::mkopt(
        $input,
        $moniker,
        $require_unique,
        $must_be,
      );

    This produces an array of arrays; the inner arrays are name/value pairs.
    Values will be either "undef" or a reference.

    Valid values for $input:

     undef    -> []
     hashref  -> [ [ key1 => value1 ] ... ] # non-ref values become undef
     arrayref -> every value followed by a ref becomes a pair: [ value => ref   ]
                 every value followed by undef becomes a pair: [ value => undef ]
                 otherwise, it becomes [ value => undef ] like so:
                 [ "a", "b", [ 1, 2 ] ] -> [ [ a => undef ], [ b => [ 1, 2 ] ] ]

    $moniker is a name describing the data, which will be used in error
    messages.

    If $require_unique is true, an error will be thrown if any name is given
    more than once.

    $must_be is either a scalar or array of scalars; it defines what kind(s)
    of refs may be values. If an invalid value is found, an exception is
    thrown. If no value is passed for this argument, any reference is valid.
    If $must_be specifies that values must be CODE, HASH, ARRAY, or SCALAR,
    then Params::Util is used to check whether the given value can provide
    that interface. Otherwise, it checks that the given value is an object
    of the kind.

    In other words:

      [ qw(SCALAR HASH Object::Known) ]

    Means:

      _SCALAR0($value) or _HASH($value) or _INSTANCE($value, 'Object::Known')

  mkopt_hash
      my $opt_hash = Data::OptList::mkopt_hash($input, $moniker, $must_be);

    Given valid "mkopt" input, this routine returns a reference to a hash.
    It will throw an exception if any name has more than one value.

EXPORTS
    Both "mkopt" and "mkopt_hash" may be exported on request.

AUTHOR
    Ricardo SIGNES, "<rjbs@cpan.org>"

BUGS
    Please report any bugs or feature requests at <http://rt.cpan.org>. I
    will be notified, and then you'll automatically be notified of progress
    on your bug as I make changes.

COPYRIGHT
    Copyright 2006-2007, Ricardo SIGNES. This program is free software; you
    can redistribute it and/or modify it under the same terms as Perl
    itself.