NAME
SYNOPSIS
DESCRIPTION
INTERFACE
- Choosing non-default names
DEPENDENCIES
ACKNOWLEDGEMENTS
SEE ALSO
AUTHORS
COPYRIGHT
- The "MIT" License

NAME

selfvars - Provide $self and @args variables for OO programs

SYNOPSIS

    package MyClass;

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

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

    ### 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};
    }

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 %{$_[0]}.

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.

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

AUTHORS

Audrey Tang <cpan@audreyt.org>

COPYRIGHT

This software is released under the MIT license cited below.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

CPAN RT