NAME

selfvars - Provide $self, @args, %opts and %hopts variables for OO programs

SYNOPSIS

package MyClass;

### Import $self, @args, %opts and %hopts into your package:
use selfvars;

### Or name the variables explicitly:
# use selfvars -self => 'self', -args => 'args', -opts => 'opts', -hopts => 'hopts';

### Write the constructor as usual:
sub new {
    return bless({}, shift);
}

### Use $self in place of $_[0]:
sub foo {
    $self->{foo};
}

### Use @args in place of @_[1..$#_]:
sub bar {
    my ($foo, $bar) = @args;
    $self->{foo} = $foo;
    $self->{bar} = $bar;
}

### Use %opts in place of %{$_[1]}:
sub baz {
    $self->{x} = $opts{x};
    $self->{y} = $opts{y};
}
### Use %hopts with $obj->yada( x => 1, y => 2 ) call syntax
sub yada {
    $self->{x} = $hopts{x}
    $self->{y} = $hopts{y}
}

DESCRIPTION

This moudles exports three special variables: $self, @args and %opts.

They are really just handy helpers to get rid of:

my $self = shift;

Behind the scenes, $self is simply tied to $_[0], @args to @_[1..$#_], and %opts to %{$_[1]}.

Currently, both $self and @args are read-only; this means you cannot mutate them:

$self = 'foo';              # error
my $foo = shift @args;      # error

This restriction may be lifted at a later version of this module, or turned into a configurable option instead.

However, %opts is not read-only, and can be mutated freely:

$opts{x} = 'y';             # okay
delete $opts{x};            # also okay

INTERFACE

$self

Returns the current object.

@args

Returns the argument list.

%opts

Returns the first argument, which must be a hash reference, as a hash.

%hopts

Returns the arguments list as a hash.

Choosing non-default names

You can choose alternative variable names with explicit import arguments:

# Use $this and @vars instead of $self and @args, leaving %opts alone:
use selfvars -self => 'this', -args => 'vars', -opts;

# Use $this but leave @args and %opts alone:
use selfvars -self => 'this', -args, -opts;

# Use @vars but leave $self and %opts alone:
use selfvars -args => 'vars', -self, -opts;

You may also omit a variable name from the explicit import arguments:

# Import $self but not @args nor %opts:
use selfvars -self => 'self';

# Same as the above:
use selfvars -self;

# Import $self and %opts but not @args:
use selfvars -self, -opts;

DEPENDENCIES

None.

ACKNOWLEDGEMENTS

This module was inspired and based on Kang-min Liu (gugod)'s self.pm.

As seen on #perl:

<gugod> audreyt: selfvars.pm looks exactly like what I want self.pm to be in the beginning
<gugod> audreyt: but I can't sort out the last BEGIN{} block like you did.
<gugod> audreyt: that's a great job :D

SEE ALSO

self

AUTHORS

唐鳳 <cpan@audreyt.org>

CC0 1.0 Universal

To the extent possible under law, 唐鳳 has waived all copyright and related or neighboring rights to selfvars.

This work is published from Taiwan.

http://creativecommons.org/publicdomain/zero/1.0

cpanm selfvars

perl -MCPAN -e shell
install selfvars