Data::OptList(3pm) User Contributed Perl Documentation Data::OptList(3pm)
NAME
Data::OptList - parse and validate simple name/value option pairs
VERSION
version 0.113
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
This library should run on perls released even a long time ago. It
should work on any version of perl released in the last five years.
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 <cpan@semiotic.systems>
CONTRIBUTORS
• Olivier Mengué <dolmen@cpan.org>
• Ricardo Signes <rjbs@semiotic.systems>
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.
perl v5.36.0 2023-01-06 Data::OptList(3pm)
Generated by dwww version 1.15 on Fri Jun 21 22:14:54 CEST 2024.