phpman > perldoc > Data::OptList(3pm)

NAME
    Data::OptList - parse and validate simple name/value option pairs

VERSION
    version 0.112

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... and it's got a bug! It looked right, didn't it? Well, the "xyz => {
    ... }" gets consumed by the map, and we don't get the data we wanted.

    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.

PERL VERSION SUPPORT
    This module has a long-term perl support period. That means it will not require a version of
    perl released fewer than five years ago.

    Although it may work on older versions of perl, no guarantee is made that the minimum required
    version will not be increased. The version may be increased for any reason, and there is no
    promise that patches will be accepted to lower the minimum required perl.

FUNCTIONS
  mkopt
      my $opt_list = Data::OptList::mkopt($input, \%arg);

    Valid arguments are:

      moniker        - a word used in errors to describe the opt list; encouraged
      require_unique - if true, no name may appear more than once
      must_be        - types to which opt list values are limited (described below)
      name_test      - a coderef used to test whether a value can be a name
                       (described below, but you probably don't want this)

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

    Positional parameters may be used for compatibility with the old "mkopt" interface:

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

    Valid values for $input:

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

    By default, a *name* is any defined non-reference. The "name_test" parameter can be a code ref
    that tests whether the argument passed it is a name or not. This should be used rarely.
    Interactions between "require_unique" and "name_test" are not yet particularly elegant, as
    "require_unique" just tests string equality. This may change.

    The "must_be" parameter 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 AT semiotic.systems>

CONTRIBUTOR
    Olivier Mengué <dolmen AT cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2006 by Ricardo Signes.

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