Getopt::EX::Hashed(3pm)

NAME
Getopt::EX::Hashed - Hash object automation for Getopt::Long

VERSION
Version 1.0702

SYNOPSIS
  # script/foo
  use App::foo;
  App::foo->new->run();

  # lib/App/foo.pm
  package App::foo;

  use Getopt::EX::Hashed; {
      Getopt::EX::Hashed->configure( DEFAULT => [ is => 'rw' ] );
      has start    => ' =i  s begin ' , default => 1;
      has end      => ' =i  e       ' ;
      has file     => ' =s@ f       ' , any => qr/^(?!\.)/;
      has score    => ' =i          ' , min => 0, max => 100;
      has answer   => ' =i          ' , must => sub { $_[1] == 42 };
      has mouse    => ' =s          ' , any => [ 'Frankie', 'Benjy' ];
      has question => ' =s          ' , any => qr/^(life|universe|everything)$/i;
  } no Getopt::EX::Hashed;

  sub run {
      my $app = shift;
      use Getopt::Long;
      $app->getopt or pod2usage();
      if ($app->answer == 42) {
          $app->question //= 'life';
          ...

DESCRIPTION
Getopt::EX::Hashed is a module to automate the creation of a hash object to store command line option values for Getopt::Long and compatible modules including Getopt::EX::Long. The module name shares the Getopt::EX prefix, but it works independently from other modules in Getopt::EX, so far.

The major objective of this module is integrating initialization and specification into a single place. It also provides a simple validation interface.

Accessor methods are automatically generated when "is" parameter is given. If the same function is already defined, the program causes fatal error. By default, accessors are removed from the package namespace when the object is destroyed. This allows the same class to be used more than once within a single script — for example, when a module using Hashed-based objects is called from multiple places.

Objects created by copying (e.g. via Clone) are not considered owners of the accessors. Only the object originally created by "new" removes the accessors on destruction, so cloned objects can be safely destroyed without affecting the original object or its class. To keep accessors after destruction, set "REMOVE_ACCESSOR" to false.

FUNCTION

  has
Declare option parameters in the following form. The parentheses are for clarity only and may be omitted.

    has option_name => ( param => value, ... );

For example, to define the option "--number", which takes an integer value as a parameter, and also can be used as "-n", do the following

    has number => spec => "=i n";

The accessor is created with the first name. In this example, the accessor will be defined as "$app->number".

If an array reference is given, multiple names can be declared at once.

    has [ 'left', 'right' ] => ( spec => "=i" );

If the name starts with plus ("+"), the given parameter updates the existing setting.

    has '+left' => ( default => 1 );

As for the "spec" parameter, the label can be omitted if it is the first parameter.

    has left => "=i", default => 1;

If the number of parameters is odd, the first parameter is treated as having an implicit label: "action" if it is a code reference, "spec" otherwise.

Following parameters are available.

[ spec => ] string
    Give option specification. "spec =>" label can be omitted if and only if it is the first parameter.

    In string, option spec and alias names are separated by white space, and can show up in any order.

    To have an option called "--start" that takes an integer as its value and can also be used with the names "-s" and "--begin", declare as follows.

        has start => "=i s begin";

    The above declaration will be compiled into the following string.

        start|s|begin=i

    which conforms to the "Getopt::Long" definition. Of course, you can write it as:

        has start => "s|begin=i";

    If the name and aliases contain underscore ("_"), another alias name is defined with dash ("-") in place of underscores.

        has a_to_z => "=s";

    The above declaration will be compiled into the following string.

        a_to_z|a-to-z=s

    If no option spec is needed, give an empty (or white space only) string as a value. Without a spec string, the member will not be treated as an option.

alias => string
    Additional alias names can be specified by the alias parameter too. There is no difference from the ones in the "spec" parameter.

        has start => "=i", alias => "s begin";

is => "ro" | "rw"
    To produce an accessor method, the "is" parameter is necessary. Set the value "ro" for read-only, "rw" for read-write.

    Read-write accessor has lvalue attribute, so it can be assigned to. You can use like this:

        $app->foo //= 1;

    This is much simpler than writing as in the following.

        $app->foo(1) unless defined $app->foo;

    If you want to make accessors for all following members, use "configure" to set the "DEFAULT" parameter.

        Getopt::EX::Hashed->configure( DEFAULT => [ is => 'rw' ] );

    If you don't like assignable accessors, configure the "ACCESSOR_LVALUE" parameter to 0. Because accessors are generated at the time of "new", this value is effective for all members.

default => value | coderef
    Set default value. If no default is given, the member is initialized as "undef".

    If the value is a reference to an ARRAY or HASH, a shallow copy is created for each "new" call. The elements are not deep-copied, so if any element is itself a reference, the referenced data is shared across instances.

    If a code reference is given, it is called at the time of new to get default value. This is effective when you want to evaluate the value at the time of execution, rather than declaration. If you want to define a default action, use the action parameter. If you want to set code reference as the initial value, you must specify a code reference that returns a code reference.

    If a reference to SCALAR is given, the option value is stored in the data indicated by the reference, not in the hash object member. In this case, the expected value cannot be obtained by accessing the hash member.

[ action => ] coderef
    Parameter "action" takes code reference which is called to process the option. "action =>" label can be omitted if and only if it is the first parameter.

    When called, hash object is passed as $_.

        has [ qw(left right both) ] => '=i';
        has "+both" => sub {
            $_->{left} = $_->{right} = $_[1];
        };

    You can use this for "<>" to handle non-option arguments. In that case, the spec parameter does not matter and is not required.

        has ARGV => default => [];
        has "<>" => sub {
            push @{$_->{ARGV}}, $_[0];
        };

Following parameters are all for data validation. First, "must" is a generic validator and can implement anything. Others are shortcuts for common rules.

must => coderef | [ coderef ... ]
    Parameter "must" takes a code reference to validate option values. It takes the same arguments as "action" and returns a boolean. With the following example, option --answer takes only 42 as a valid value.

        has answer => '=i',
            must => sub { $_[1] == 42 };

    If multiple code references are given, all code must return true.

        has answer => '=i',
            must => [ sub { $_[1] >= 42 }, sub { $_[1] <= 42 } ];

min => number
max => number
    Set the minimum and maximum limit for the argument.

any => arrayref | qr/regex/ | coderef
    Set the valid string parameter list. Each item can be a string, a regex reference, or a code reference. The argument is valid when it is the same as, or matches any item of the given list. If the value is not an arrayref, it is taken as a single item list (regexpref or coderef usually).

    Following declarations are almost equivalent, except second one is case insensitive.

        has question => '=s',
            any => [ 'life', 'universe', 'everything' ];

        has question => '=s',
            any => qr/^(life|universe|everything)$/i;

    If you are using optional argument, don't forget to include default value in the list. Otherwise it causes validation error.

        has question => ':s',
            any => [ 'life', 'universe', 'everything', '' ];

METHOD

  new
A class method that creates a new hash object. Initializes all members with their default values and creates accessor methods as configured. Returns a blessed hash reference. The hash keys are locked if LOCK_KEYS is enabled.

  optspec
Returns the option specification list which can be passed to the "GetOptions" function.

    GetOptions($obj->optspec)

"GetOptions" has the capability of storing values in a hash by giving the hash reference as the first argument, but it is not necessary.

  getopt [ arrayref ]
Calls the appropriate function defined in the caller's context to process options.

    $obj->getopt

    $obj->getopt(\@argv);

The above examples are shortcuts for the following code.

    GetOptions($obj->optspec)

    GetOptionsFromArray(\@argv, $obj->optspec)

  use_keys keys
When LOCK_KEYS is enabled, accessing a non-existent member causes an error. Use this method to declare new member keys before accessing them.

    $obj->use_keys( qw(foo bar) );

If you want to access arbitrary keys, unlock the object.

    use Hash::Util 'unlock_keys';
    unlock_keys %{$obj};

You can change this behavior by "configure" with "LOCK_KEYS" parameter.

  configure label => value, ...
Use class method "Getopt::EX::Hashed->configure()" before creating an object; this information is stored separately for each calling package. After calling new(), the package-level configuration is copied into the object for its use. Use "$obj->configure()" to update object-level configuration.

The following configuration parameters are available.

LOCK_KEYS (default: 1)
    Lock hash keys. This prevents typos or other mistakes from creating unintended hash entries.

REPLACE_UNDERSCORE (default: 1)
    Automatically create option aliases with underscores replaced by dashes.

REMOVE_UNDERSCORE (default: 0)
    Automatically create option aliases with underscores removed.

GETOPT (default: 'GetOptions')
GETOPT_FROM_ARRAY (default: 'GetOptionsFromArray')
    Set the function name called from the "getopt" method.

ACCESSOR_PREFIX (default: '')
    When specified, it will be prepended to the member name to make the accessor method. If "ACCESSOR_PREFIX" is defined as "opt_", the accessor for member "file" will be "opt_file".

ACCESSOR_LVALUE (default: 1)
    If true, read-write accessors have the lvalue attribute. Set to zero if you don't like that behavior.

REMOVE_ACCESSOR (default: 1)
    If true, accessor methods are removed from the package namespace when the object is destroyed. This allows the same class to be used multiple times within a single script without causing conflicts.

    Only the object originally created by "new" is considered the owner of the accessors. Objects created by copying (e.g. via Clone) are not owners, so destroying a clone does not remove the accessors even when "REMOVE_ACCESSOR" is true.

    Set to false if you want accessors to persist beyond the lifetime of the object, for example when the accessor methods are intended to be part of the class's permanent public interface.

DEFAULT
    Set default parameters. When "has" is called, DEFAULT parameters are inserted before the explicit parameters. If a parameter appears in both, the explicit one takes precedence. Incremental calls with "+" are not affected.

    A typical use of DEFAULT is "is" to prepare accessor methods for all following hash entries. Declare "DEFAULT => []" to reset.

        Getopt::EX::Hashed->configure(DEFAULT => [ is => 'ro' ]);

  reset
Reset the class to the original state.

SEE ALSO
Getopt::Long

Getopt::EX, Getopt::EX::Long

AUTHOR
Kazumasa Utashiro

COPYRIGHT
The following copyright notice applies to all the files provided in this distribution, including binary files, unless explicitly noted otherwise.

Copyright 2021-2026 Kazumasa Utashiro

LICENSE
This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.