Class::MakeMethods::Standard::Hash - Standard hash methods
package MyObject;
use Class::MakeMethods::Standard::Hash (
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');
The Standard::Hash suclass of MakeMethods provides a basic constructor and
accessors for blessed-hash object instances.
When you "use" this package, the method names you provide as arguments
cause subroutines to be generated and installed in your module.
See "Calling Conventions" in Class::MakeMethods::Standard for more
information.
To declare methods, pass in pairs of a method-type name followed by one or more
method names.
Valid method-type names for this package are listed in "METHOD GENERATOR
TYPES".
See "Declaration Syntax" in Class::MakeMethods::Standard and
"Parameter Syntax" in Class::MakeMethods::Standard for more
information.
For each method name passed, returns a subroutine with the following
characteristics:
- •
- Has a reference to a sample item to copy. This defaults to
a reference to an empty hash, but you may override this with the
"'defaults' =" hash_ref> method parameter.
- •
- If called as a class method, makes a new hash and blesses
it into that class.
- •
- If called on a hash-based instance, makes a copy of it and
blesses the copy into the same class as the original instance.
- •
- If passed a list of key-value pairs, appends them to the
new hash. These arguments override any copied values, and later arguments
with the same name will override earlier ones.
- •
- Returns the new instance.
Sample declaration and usage:
package MyObject;
use Class::MakeMethods::Standard::Hash (
new => 'new',
);
...
# Bare constructor
my $empty = MyObject->new();
# Constructor with initial values
my $obj = MyObject->new( foo => 'Foozle', bar => 'Barbados' );
# Copy with overriding value
my $copy = $obj->new( bar => 'Bob' );
For each method name passed, uses a closure to generate a subroutine with the
following characteristics:
- •
- Must be called on a hash-based instance.
- •
- Has a specific hash key to use to access the related value
for each instance. This defaults to the method name, but you may override
this with the "'hash_key' =" string> method
parameter.
- •
- If called without any arguments returns the current
value.
- •
- If called with an argument, stores that as the value, and
returns it,
Sample declaration and usage:
package MyObject;
use Class::MakeMethods::Standard::Hash (
scalar => 'foo',
);
...
# Store value
$obj->foo('Foozle');
# Retrieve value
print $obj->foo;
For each method name passed, uses a closure to generate a subroutine with the
following characteristics:
- •
- Must be called on a hash-based instance.
- •
- Has a specific hash key to use to access the related value
for each instance. This defaults to the method name, but you may override
this with the "'hash_key' =" string> method
parameter.
- •
- The value for each instance will be a reference to an array
(or undef).
- •
- If called without any arguments, returns the contents of
the array in list context, or an array reference in scalar context (or
undef).
- •
- If called with a single array ref argument, sets the
contents of the array to match the contents of the provided one.
- •
- If called with a single numeric argument, uses that
argument as an index to retrieve from the referenced array, and returns
that value (or undef).
- •
- If called with a two arguments, the first undefined and the
second an array ref argument, uses that array's contents as a list of
indexes to return a slice of the referenced array.
- •
- If called with a list of argument pairs, each with a
numeric index and an associated value, 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 will be
overwritten, and later arguments with the same index will override earlier
ones. Returns the current array-ref value.
- •
- If called with a list of argument pairs, each with the
first item being a reference to an array of up to two numbers, loops over
each pair and uses those numbers to splice the value array.
The first controlling number is the position at which the splice will begin.
Zero will start before the first item in the list. Negative numbers count
backwards from the end of the array.
The second number is the number of items to be 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 the items that removed from the array, if any.
Sample declaration and usage:
package MyObject;
use Class::MakeMethods::Standard::Hash (
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' );
For each method name passed, uses a closure to generate a subroutine with the
following characteristics:
- •
- Must be called on a hash-based instance.
- •
- Has a specific hash key to use to access the related value
for each instance. This defaults to the method name, but you may override
this with the "'hash_key' =" string> method
parameter.
- •
- The value for each instance will be a reference to a hash
(or undef).
- •
- If called without any arguments, returns the contents of
the hash in list context, or a hash reference in scalar context (or
undef).
- •
- If called with one non-ref argument, uses that argument as
an index to retrieve from the referenced hash, and returns that value (or
undef).
- •
- If called with one array-ref argument, uses the contents of
that array to retrieve a slice of the referenced hash.
- •
- If called with one hash-ref argument, sets the contents of
the referenced hash to match that provided.
- •
- If called with a list of key-value pairs, 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 will be overwritten, and later arguments with the same key will
override earlier ones. 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::Standard::Hash (
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() } = ();
For each method name passed, uses a closure to generate a subroutine with the
following characteristics:
- •
- Must be called on a hash-based instance.
- •
- Has a specific hash key to use to access the related value
for each instance. This defaults to the method name, but you may override
this with the "'hash_key' =" string> method
parameter.
- •
- The value for each instance will be a reference to an
object (or undef).
- •
- If called without any arguments returns the current
value.
- •
- If called with an argument, stores that as the value, and
returns it,
Sample declaration and usage:
package MyObject;
use Class::MakeMethods::Standard::Hash (
object => 'foo',
);
...
# Store value
$obj->foo( Foozle->new() );
# Retrieve value
print $obj->foo;
See Class::MakeMethods for general information about this distribution.
See Class::MakeMethods::Standard for more about this family of subclasses.