Data::OptList - parse and validate simple name/value option pairs
version 0.112
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 => [ ... ], ],
]);
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.
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.
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')
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.
Both mkopt and mkopt_hash may be exported on request.
Ricardo Signes <rjbs@semiotic.systems>
Olivier Mengué <dolmen@cpan.org>
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.
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