Provided by: libclass-methodmaker-perl_2.19-1_amd64 bug

NAME

       Class::MethodMaker::Engine - The parameter passing, method installation &
       non-data-structure methods of Class::MethodMaker.

SYNOPSIS

       This class is for internal implementation only.  It is not a public API.

       The non-data-structure methods do form part of the public API, but not called directly:
       rather, called through the "use"/"import" interface, as for data-structure methods.

The Class::MethodMaker Method Installation Engine

   import
       This performs argument parsing ready for calling create_methods.  In particular, this is
       the point at which v1 & v2 calls are distinguished.

       This is implicitly called as part of a "use" statement:

         use Class::MethodMaker
           [ scalar => [qw/ foo bar baz /],
             new    => [qw/ new /]        ,
           ];

       is equivalent to

         Class::MethodMaker->import([scalar => [qw/ foo bar baz /],
                                     new    => [qw/ new /]        ,
                                    ]);

       See perldoc -f use for details of this equivalence.

       The methods created are installed into the class calling the import - or more accurately,
       the first class up the calling stack that is not "Class::MethodMaker" or a subclass
       thereof.

       SYNOPSIS
             Class::MethodMaker->import([scalar => [+{ -type   => 'File::Stat',
                                                       -forward => [qw/ mode size /],
                                                       '*_foo' => '*_fig',
                                                       '*_gop' => undef,
                                                       '*_bar' => '*_bar',
                                                       '*_hal' => '*_sal',
                                                      },
                                                    qw/ -static bob /,
                                                   ]
                                        ]);

   parse_options
       Parse the arguments given to import and call create_methods appropriately.  See main text
       for options syntax.

       SYNOPSIS
             Class::MethodMaker->parse_options('TargetClass',
                                               [scalar =>
                                                 [{ -type => 'File::stat',
                                                    -forward => [qw/ mode
                                                                     size /],
                                                    '*_foo' => '*_fig',
                                                    '*_gop' => undef,
                                                    '*_bar' => '*_bar',
                                                    '*_hal' => '*_sal',
                                                  },
                                                  qw( -static bob ),
                                                 ]])},

             Class::MethodMaker->parse_options('TargetClass2',
                                               [scalar =>
                                                 ['baz',
                                                  { -type => 'File::stat',
                                                    -forward => [qw/ mode
                                                                     size /],
                                                    '*_foo' => '*_fog',
                                                    '*_bar' => '*_bar',
                                                    '*_hal' => '*_sal',
                                                  },
                                                  qw( -static bob ),
                                                 ]],
                                               +{ -type => 'Math::BigInt', },
                                               +{'*_foo' => '*_fig',
                                                 '*_gop' => undef,},
                                              )},

       ARGUMENTS
           target_class
               The class into which to install components

           args
               The arguments to parse, as a single arrayref.

           options
               A hashref of options to apply to all components created by this call (subject to
               overriding by explicit option calls).

           renames
               A hashref of renames to apply to all components created by this call (subject to
               overriding by explicit rename calls).

   create_methods
       Add methods to a class.  Methods for multiple components may be added this way, but
       create_methods handles only one set of options.  parse_options is responsible for sorting
       which options to apply to which components, and calling create_methods appropriately.

       SYNOPSIS
             Class::MethodMaker->create_methods($target_class,
                                                scalar => bob,
                                                +{ static => 1,
                                                   type   => 'File::Stat',
                                                   forward => [qw/ mode size /], },
                                                +{ '*_foo' => '*_fig',
                                                   '*_gop' => undef,
                                                   '*_bar' => '*_bar',
                                                   '*_hal' => '*_sal', }
                                               );

       ARGUMENTS
           targetclass
               The class to add methods to.

           type
               The basic data structure to use for the component, e.g., "scalar".

           compname
               Component name.  The name must be a valid identifier, i.e., a continuous non-empty
               string of word ("\w") characters, of which the first may not be a digit.

           options
               A hashref.  Some options ("static", "type", "default", "default_ctor") are handled
               by the auto-extender.  These will be invoked if the name is present as a key and
               the value is true.  Any other options are passed through to the method in
               question.  The options should be named as-is; no leading hyphen should be applied
               (i.e., use "{static => 1}" not "{-static => 1}").

           renames
               A list of customer renames.  It is a hashref from method name to rename.  The
               method name is the generic name (i.e., featuring a "*" to replace with the
               component name).  The rename is the value to rename with.  It may itself contain a
               "*" to replace with the component name.  If rename is undef, the method is not
               installed.  For methods that would not be installed by default, use a rename value
               that is the same as the method name.

               So, if a type would normally install methods

                 '*_foo', '*_gop', '*_tom'

               and optionally installs (but not by default)

                 '*_bar', '*_wiz', '*_hal'

               using a renames value of

                 { '*_foo' => '*_fig',
                   '*_gop' => undef,
                   '*_bar' => '*_bar',
                   '*_hal' => '*_sal',
                 }

               with a component name of "xx", then *_foo is installed as "xx_fig", *_bar is
               installed as "xx_bar", *_wiz is not installed, *_hal is installed as "xx_sal",
               *_gop is not installed, and *_tom is installed as "xx_tom".

               The value may actually be an arrayref, in which case the function may be called by
               any of the multiple names specified.

   install_methods
       SYNOPSIS
             Class::MethodMaker->install_methods
               ($classname, { incr => sub { $i++ },
                              decr => sub { $i-- },
                            }
               );

       ARGUMENTS
           target
               The class into which the methods are to be installed

           methods
               The methods to install, as a hashref.  Keys are the method names; values are the
               methods themselves, as code refs.

Non-data-structure components

   new
         use Class::MethodMaker
           [ new => 'new' ];

       Creates a basic constructor.

       Takes a single string or a reference to an array of strings as its argument.  For each
       string creates a simple method that creates and returns an object of the appropriate
       class.

       The generated method may be called as a class method, as usual, or as in instance method,
       in which case a new object of the same class as the instance will be created.

       Options

       -hash
           The constructor will accept as arguments a list of pairs, from component name to
           initial value.  For each pair, the named component is initialized by calling the
           method of the same name with the given value.  E.g.,

             package MyClass;
             use Class::MethodMaker
               [ new    => [qw/ -hash new /],
                 scalar => [qw/ b c /],
               ];

             sub d {
               my $self = shift;
               $self->{d} = $_[0]
                 if @_;
               return $self->{d};
             }

             package main;
             # The statement below implicitly calls
             # $m->b(1); $m->c(2); $m->d(3)
             # on the newly constructed m.
             my $m = MyClass->new(b => 1, c => 2, d => 3);

           Note that this can also call user-supplied methods that have the name of the
           component.

           Instead of a list of pairs, a single hashref may also be passed, which will be
           expanded appropriately.  So the above is equivalent to:

             my $m = MyClass->new({ b => 1, c => 2, d => 3 });

           Advanced Users: Class::MethodMaker method renaming is taken into account, so even if
           the "*" method is renamed or removed, this will still work.

       -init
           This option causes the new method to call an initializer method.  The method is called
           "init" (original, eh?) by default, but the option may be given an alternative value.
           The init method is passed any arguments that were passed to the constructor, but the
           method is invoked on the newly constructed instance.

             use Class::MethodMaker
               [ new => [qw/ -init new1 /, { -init => 'bob' } => 'init2' ]];

           Constructing with new1 involves an implicit call to "init", whilst constructing with
           new2 involves an implicit call to "bob" (instead of "init").

           It is the responsibility of the user to ensure that an "init" method (or whatever
           name) is defined.

       -singleton
           Creates a basic constructor which only ever returns a single instance of the class:
           i.e., after the first call, repeated calls to this constructor return the same
           instance.  Note that the instance is instantiated at the time of the first call, not
           before.

   abstract
         use Class::MethodMaker
           [ abstract => [ qw / foo bar baz / ] ];

       This creates a number of methods that will die if called.  This is intended to support the
       use of abstract methods, that must be overridden in a useful subclass.

   copy
         use Class::MethodMaker
           [ copy => [qw/ shallow -deep deep /] ];

       This creates method that produce a copy of self.  The copy is a by default a shallow copy;
       any references will be shared by the instance upon which the method is called and the
       returned newborn.  One option is taken, "-deep", which causes the method to create deep
       copies instead (i.e., references are copied recursively).

       Implementation Note:

       Deep copies are performed using the "Storable" module if available, else "Data::Dumper".
       The "Storable" module is liable to be much quicker.  However, this implementation note is
       not an API specification: the implementation details are open to change in a future
       version as faster/better ways of performing a deep copy become available.

       Note that deep copying does not currently support the copying of coderefs, ties or XS-
       based objects.

AUTHOR

       Martyn J. Pearce <fluffy@cpan.org>