MakeMe...::Array(3pm)

okay so bestie, this is MakeMe...::Array(3pm) from User Contributed Perl Documentation, and it’s literally the Class::MakeMethods::Composite::Array page. Buckle up, we’re doing array-method lore today 💅✨

📛 NAME 📛

Class::MakeMethods::Composite::Array — Basic array methods.

✨ SYNOPSIS ✨

         package MyObject;
         use Class::MakeMethods::Composite::Array (
           new => 'new',
           scalar => [ 'foo', 'bar' ],
           array => 'my_list',
           hash => 'my_index',
         );
         ...

         my $obj = MyObject->new( foo => 'Foozle' );
         print $obj->foo();

         $obj->bar('Barbados');
         print $obj->bar();

         $obj->my_list(0 => 'Foozle', 1 => 'Bang!');
         print $obj->my_list(1);

         $obj->my_index('broccoli' => 'Blah!', 'foo' => 'Fiddle');
         print $obj->my_index('foo');

🦋 DESCRIPTION 🦋

The Composite::Array suclass of MakeMethods provides a basic constructor and accessors for blessed-array object instances. (Yes, the page says “suclass” — we’re keeping the lore 💅)

🎀 Class::MakeMethods Calling Conventions 🎀

When you use this package, the method declarations you provide as arguments cause subroutines to be generated and installed in your module.

You can also omit the arguments to use and instead make methods at runtime by passing the declarations to a subsequent call to make().

You may include any number of declarations in each call to use or make(). If methods with the same name already exist, earlier calls to use or make() win over later ones, but within each call, later declarations superceed earlier ones. (Their spelling, not mine 😭)

You can install methods in a different package by passing -TargetClass => package as your first arguments to use or make.

See Class::MakeMethods for more details.

🌈 Class::MakeMethods::Basic Declaration Syntax 🌈

The following types of Basic declarations are supported:

• generator_type => "method_name"
• generator_type => "name_1 name_2..."
• generator_type => [ "name_1", "name_2", ...]

See the "METHOD GENERATOR TYPES" section below for a list of the supported values of generator_type.

For each method name you provide, a subroutine of the indicated type will be generated and installed under that name in your module.

Method names should start with a letter, followed by zero or more letters, numbers, or underscores.

🍓 Class::MakeMethods::Composite Declaration Syntax 🍓

The Composite syntax also provides several ways to optionally associate a hash of additional parameters with a given method name.

• generator_type => [ "name_1" => { param=>value... }, ... ] — A hash of parameters to use just for this method name.

(Note: to prevent confusion with self-contained definition hashes, described below, parameter hashes following a method name must not contain the key 'name'.)

• generator_type => [ [ "name_1", "name_2", ... ] => { param=>value... } ] — Each of these method names gets a copy of the same set of parameters.
• generator_type => [ { "name"=>"name_1", param=>value... }, ... ] — By including the reserved parameter "name", you create a self contained declaration with that name and any associated hash values.

Basic declarations, as described above, are treated as having an empty parameter hash.

👑 Positional Accessors and %FIELDS 👑

Each accessor method is assigned the next available array index at which to store its value.

The mapping between method names and array positions is stored in a hash named %FIELDS in the declaring package. When a package declares its first positional accessor, its %FIELDS are initialized by searching its inheritance tree.

⚠️ Warning: Subclassing packages that use positional accessors is somewhat fragile, since you may end up with two distinct methods assigned to the same position. Specific cases to avoid are:

• If you inherit from more than one class with positional accessors, the positions used by the two sets of methods will overlap.
• If your superclass adds additional positional accessors after you declare your first, they will overlap yours.

✨ METHOD GENERATOR TYPES ✨

okay bestie, this is where the generator types do their whole main-character thing. Each one makes a method-maker, and each one has its own rules. no skipping, because the details are the whole point — each one is giving method-maker energy, periodt 💅

👑 new - Constructor 👑

For each method name passed, this returns a subroutine with the following characteristics:

• It keeps a reference to a sample item to copy. The default is a reference to an empty array, but you can override that with the "'defaults' =" array_ref> method parameter.
• Call it as a class method and it makes a new array containing values from the sample item, then blesses it into that class.
• Call it on an array-based instance and it makes a copy of that instance, then blesses the copy into the same class as the original instance.
• If you pass it a list of method-value pairs, it calls each named method with the associated value as an argument.
• Then it returns the new instance. iconic.

Sample declaration and usage:

package MyObject;
use Class::MakeMethods::Composite::Array (
  new => 'new',
);
...

# Bare constructor
my $empty = MyObject->new();

# Constructor with initial sequence of method calls
my $obj = MyObject->new( foo => 'Foozle', bar => 'Barbados' );

# Copy with overriding sequence of method calls
my $copy = $obj->new( bar => 'Bob' );

🎀 new_with_values - Constructor 🎀

For each method name passed, this returns a subroutine with the following characteristics:

• It may be called as a class method, or (equivalently) on any existing object of that class.
• It creates an array, blesses it into the class, and returns the new instance.
• If you give it no arguments, the returned array is empty. If you pass a single array-ref argument, it copies that array's contents into the new array. If you call it with multiple arguments, it copies those into the new array. Important: this is a "shallow" copy, not a "deep" clone. do not forget that part, bestie 😭

Sample declaration and usage:

package MyObject;
use Class::MakeMethods::Composite::Array (
  new => 'new',
);
...

# Bare constructor
my $empty = MyObject->new();

# Constructor with initial sequence of method calls
my $obj = MyObject->new( foo => 'Foozle', bar => 'Barbados' );

# Copy with overriding sequence of method calls
my $copy = $obj->new( bar => 'Bob' );

🌸 scalar - Instance Accessor 🌸

For each method name passed, this uses a closure to generate a subroutine with the following characteristics:

• It must be called on an array-based instance.
• It determines the array position associated with the method name, and uses that as an index into each instance to access the related value. That defaults to the next available slot in %FIELDS, but you can override it with the "'array_index' =" number> method parameter, or by pre-filling the contents of %FIELDS.
• Call it with no arguments and it returns the current value (or undef).
• Call it with one argument and it stores that as the value, then returns it.
• Call it with multiple arguments and it stores a reference to a new array containing those arguments, then returns that array reference.

Sample declaration and usage:

package MyObject;
use Class::MakeMethods::Composite::Array (
  scalar => 'foo',
);
...

# Store value
$obj->foo('Foozle');

# Retrieve value
print $obj->foo;

🦋 array - Instance Ref Accessor 🦋

For each method name passed, this uses a closure to generate a subroutine with the following characteristics:

• It must be called on an array-based instance.
• It determines the array position associated with the method name, and uses that as an index into each instance to access the related value. That defaults to the next available slot in %FIELDS, but you can override it with the "'array_index' =" number> method parameter, or by pre-filling the contents of %FIELDS.
• The value for each instance will be a reference to an array (or undef).
• Call it with no arguments and it returns the current array-ref value (or undef).
• Call it with a single non-ref argument and it uses that argument as an index to retrieve from the referenced array, then returns that value (or undef).
• Call it with a single array ref argument and it uses that list to return a slice of the referenced array.
• Call it with a list of argument pairs, where each pair has a non-ref index and an associated value, and it stores the value at the given index in the referenced array. If the instance's value was previously undefined, a new array is autovivified. The current value in each position gets overwritten, and later arguments with the same index override earlier ones. It returns the current array-ref value.
• Call it with a list of argument pairs where the first item is a reference to an array of up to two numbers, and it loops over each pair and uses those numbers to splice the value array.

The first controlling number is the position where the splice begins. Zero starts before the first item in the list. Negative numbers count backwards from the end of the array.

The second number is how many items get removed from the list. If it is omitted, or undefined, or zero, no items are removed. If it is a positive integer, that many items will be returned.

If both numbers are omitted, or are both undefined, they default to containing the entire value array.

If the second argument is undef, no values will be inserted; if it is a non-reference value, that one value will be inserted; if it is an array-ref, its values will be copied.

The method returns whatever items got removed from the array, if any. slice and splice realness ✨

Sample declaration and usage:

package MyObject;
use Class::MakeMethods::Composite::Array (
  array => 'bar',
);
...

# Clear and set contents of list
print $obj->bar([ 'Spume', 'Frost' ] );

# Set values by position
$obj->bar(0 => 'Foozle', 1 => 'Bang!');

# Positions may be overwritten, and in any order
$obj->bar(2 => 'And Mash', 1 => 'Blah!');

# Retrieve value by position
print $obj->bar(1);

# Direct access to referenced array
print scalar @{ $obj->bar() };

There are also calling conventions for slice and splice operations:

# Retrieve slice of values by position
print join(', ', $obj->bar( undef, [0, 2] ) );

# Insert an item at position in the array
$obj->bar([3], 'Potatoes' );

# Remove 1 item from position 3 in the array
$obj->bar([3, 1], undef );

# Set a new value at position 2, and return the old value
print $obj->bar([2, 1], 'Froth' );

🍓 hash - Instance Ref Accessor 🍓

For each method name passed, this uses a closure to generate a subroutine with the following characteristics:

• It must be called on an array-based instance.
• It determines the array position associated with the method name, and uses that as an index into each instance to access the related value. That defaults to the next available slot in %FIELDS, but you can override it with the "'array_index' =" number> method parameter, or by pre-filling the contents of %FIELDS.
• The value for each instance will be a reference to a hash (or undef).
• Call it with no arguments and it returns the contents of the hash in list context, or a hash reference in scalar context (or undef).
• Call it with one non-ref argument and it uses that argument as an index to retrieve from the referenced hash, then returns that value (or undef).
• Call it with one array-ref argument and it uses the contents of that array to retrieve a slice of the referenced hash.
• Call it with one hash-ref argument and it sets the contents of the referenced hash to match the one provided.
• Call it with a list of key-value pairs and it stores the value under the given key in the referenced hash. If the instance's value was previously undefined, a new hash is autovivified. The current value under each key gets overwritten, and later arguments with the same key override earlier ones. It returns the contents of the hash in list context, or a hash reference in scalar context.

Sample declaration and usage:

package MyObject;
use Class::MakeMethods::Composite::Array (
  hash => 'baz',
);
...

# Set values by key
$obj->baz('foo' => 'Foozle', 'bar' => 'Bang!');

# Values may be overwritten, and in any order
$obj->baz('broccoli' => 'Blah!', 'foo' => 'Fiddle');

# Retrieve value by key
print $obj->baz('foo');

# Retrieve slice of values by position
print join(', ', $obj->baz( ['foo', 'bar'] ) );

# Direct access to referenced hash
print keys %{ $obj->baz() };

# Reset the hash contents to empty
@{ $obj->baz() } = ();

💜 object - Instance Ref Accessor 💜

For each method name passed, this uses a closure to generate a subroutine with the following characteristics:

• It must be called on an array-based instance.
• It determines the array position associated with the method name, and uses that as an index into each instance to access the related value. That defaults to the next available slot in %FIELDS, but you can override it with the "'array_index' =" number> method parameter, or by pre-filling the contents of %FIELDS.
• The value for each instance will be a reference to an object (or undef).
• Call it with no arguments and it returns the current value.
• Call it with one argument and it stores that as the value, then returns it.

Sample declaration and usage:

package MyObject;
use Class::MakeMethods::Composite::Hash (
  object => 'foo',
);
...

# Store value
$obj->foo( Foozle->new() );

# Retrieve value
print $obj->foo;

---

👀 SEE ALSO 👀

See Class::MakeMethods for the general info about this distribution. go read it, bestie 🫶

See Class::MakeMethods::Composite for more about this family of subclasses. family lore ✨

That's the whole vibe from perl v5.36.0, dated 2022-10-13, for MakeMe...::Array(3pm). Now go make your arrays iconic, bestie 💖✨