Class::MethodMaker::arUser3Contributed Perl DocumeClass::MethodMaker::array(3)NAME
Class::Method::array - Create methods for handling an array value.
SYNOPSIS
use Class::MethodMaker
[ array => [qw/ x /] ];
$instance->x; # empty
$instance->x(1, 1, 2, 3, 5, 8);
$instance->x_count == 6; # true
$instance->x = (13, 21, 34);
$instance->x_index(1) == 21; # true
DESCRIPTION
Creates methods to handle array values in an object. For a component
named "x", by default creates methods "x", "x_reset", "x_clear",
"x_isset", "x_count", "x_index", "x_push", "x_pop", "x_unshift",
"x_shift", "x_splice".
Methods available are:
"*"
Created by default. This method returns the list of values stored in
the slot. If any arguments are provided to this method, they replace
the current list contents. In an array context it returns the values
as an array and in a scalar context as a reference to an array. Note
that this reference is no longer a direct reference to the storage, in
contrast to Class::MethodMaker v1. This is to protect encapsulation.
See x_ref if you need that functionality (and are prepared to take the
associated risk.) This function no longer auto-expands arrayrefs input
as arguments, since that makes it awkward to set individual values to
arrayrefs. See x_setref for that functionality.
If a default value is in force, then that value will be auto-vivified
(and therefore set) for each otherwise unset (not not defined) value up
to the array max (so new items will not be appended)
*_reset
Created by default. Called without an argument, this resets the
component as a whole; deleting any associated storage, and returning
the component to its default state. Normally, this means that *_isset
will return false, and "*" will return undef. If "-default" is in
effect, then the component will be set to the default value, and
*_isset will return true. If "-default_ctor" is in effect, then the
default subr will be invoked, and its return value used to set the
value of the component, and *_isset will return true.
If called with arguments, these arguments are treated as indexes into
the component, and the individual elements thus referenced are reset
(their storage deleted, so that *_isset(n) will return false for
appropriate n, except where "-default" or "-default_ctor" are in force,
as above). As with perl arrays, resetting the highest set value
implicitly decreases the count (but x_reset(n) never unsets the
aggregate itself, even if all the elements are not set).
*_clear
package MyClass;
use Class::MethodMaker
[ scalar => [{'*_clear' => '*_clear'}, 'a'],
new => new, ];
package main;
my $m = MyClass->new;
$m->a(5);
$a = $m->a; # 5
$x = $m->a_isset; # true
$m->a_clear;
$a = $m->a; # *undef*
$x = $m->a_isset; # true
Created on request. A shorthand for setting to undef. Note that the
component will be set to undef, not reset, so *_isset will return true.
*_isset
Created by default. Whether the component is currently set. This is
different from being defined; initially, the component is not set (and
if read, will return undef); it can be set to undef (which is a set
value, which also returns undef). Having been set, the only way to
unset the component is with <*_reset>.
If a default value is in effect, then <*_isset> will always return
true.
"*_isset()" tests the component as a whole. *_isset(a) tests the
element indexed by a. "*_isset(a,b)" tests the elements indexed by a,
b, and returns the logical conjunction (and) of the tests.
*_count
Created by default. Returns the number of elements in this component.
This is not affected by presence (or lack) of a "default" (or
"default_ctor"). Returns "undef" if whole component not set (as per
*_isset).
*_index
Created by default. Takes a list of indices, returns a list of the
corresponding values.
If a default (or a default ctor) is in force, then a lookup by index
will vivify & set to the default the respective elements (and therefore
the aggregate data-structure also, if it's not already).
Beware of a bug in perl 5.6.1 that will sometimes invent values in
previously unset slots of arrays that previously contained a value.
So, vivifying a value (e.g. by x_index(2)) where x_index(1) was
previously unset might cause x_index(1) to be set spuriously. This is
fixed in 5.8.0.
*_push
Created by default. Push item(s) onto the end of the list. No return
value.
*_pop
Created by default. Given a number, pops that many items off the end of
the list, and returns them (as a ref in scalar context, as a list in
list context). Without an arg, always returns a single element. Given
a number, returns them in array order (not in reverse order as multiple
pops would).
*_unshift
Created by default. Push item(s) onto the start of the list. No return
value.
*_shift
Created by default. Given a number, shifts that many items off the
start of the list, and returns them (as a ref in scalar context, as a
list in list context). Without an arg, always returns a single
element. Given a number, returns them in array order.
*_splice
Created by default. Arguments as for perldoc perlfunc splice. Returns
an arrayref in scalar context (even if a single item is spliced), and a
list in list context.
*_get
Created on request. Retrieves the value of the component without
setting (ignores any arguments passed).
*_set
@n = $x->a; # (1,2,3)
$x->a_set(1=>4,3=>7);
@n = $x->a; # (1,4,3,7)
Created by default. Takes a list, treated as pairs of index => value;
each given index is set to the corresponding value. No return.
If two arguments are given, of which the first is an arrayref, then it
is treated as a list of indices of which the second argument (which
must also be an arrayref) are the corresponding values. Thus the
following two commands are equivalent:
$x->a_set(1=>4,3=>7);
$x->a_set([1,3],[4,7]);
perl v5.18.1 2013-09-27 Class::MethodMaker::array(3)
