Data::OptList(3p)

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

VERSION
version 0.104

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.

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.