Class::XSAccessor::Array - Generate fast XS accessors without runtime

      package MyClassUsingArraysAsInternalStorage;
      use Class::XSAccessor::Array
        constructor => 'new',
        getters => {
          get_foo => 0, # 0 is the array index to access
          get_bar => 1,
        setters => {
          set_foo => 0,
          set_bar => 1,
        accessors => { # a mutator
          buz => 2,
        predicates => { # test for definedness
          has_buz => 2,
        true => [ 'is_token', 'is_whitespace' ],
        false => [ 'significant' ];
  # The imported methods are implemented in fast XS.
  # normal class code here.

    The module implements fast XS accessors both for getting at and setting
    an object attribute. Additionally, the module supports mutators and
    simple predicates ("has_foo()" like tests for definedness of an
    attributes). The module works only with objects that are implemented as
    arrays. Using it on hash-based objects is bound to make your life
    miserable. Refer to Class::XSAccessor for an implementation that works
    with hash-based objects.

    A simple benchmark showed more than a factor of two performance
    advantage over writing accessors in Perl.

    Since version 0.10, the module can also generate simple constructors
    (implemented in XS) for you. Simply supply the "constructor =>
    'constructor_name'" option or the "constructors => ['new', 'create',
    'spawn']" option. These constructors do the equivalent of the following
    perl code:

      sub new {
        my $class = shift;
        return bless [], ref($class)||$class;

    That means they can be called on objects and classes but will not clone
    objects entirely. Note that any parameters to new() will be discarded!
    If there is a better idiom for array-based objects, let me know.

    While generally more obscure than hash-based objects, objects using
    blessed arrays as internal representation are a bit faster as its
    somewhat faster to access arrays than hashes. Accordingly, this module
    is slightly faster (~10-15%) than Class::XSAccessor, which works on
    hash-based objects.

    The method names may be fully qualified. In the example of the synopsis,
    you could have written "MyClass::get_foo" instead of "get_foo". This
    way, you can install methods in classes other than the current class.
    See also: The "class" option below.

    Since version 1.01, you can generate extremely simply methods which
    simply return true or false (and always do so). If that seems like a
    really superfluous thing to you, then think of a large class hierarchy
    with interfaces such as PPI. This is implemented as the "true" and
    "false" options, see synopsis.

    In addition to specifying the types and names of accessors, you can add
    options which modify behaviour. The options are specified as key/value
    pairs just as the accessor declaration. Example:

      use Class::XSAccessor::Array
        getters => {
          get_foo => 0,
        replace => 1;

    The list of available options is:

    Set this to a true value to prevent "Class::XSAccessor::Array" from
    complaining about replacing existing subroutines.

    Set this to a true value to change the return value of setters and
    mutators (when called with an argument). If "chained" is enabled, the
    setters and accessors/mutators will return the object. Mutators called
    without an argument still return the value of the associated attribute.

    As with the other options, "chained" affects all methods generated in
    the same "use Class::XSAccessor::Array ..." statement.

    By default, the accessors are generated in the calling class. Using the
    "class" option, you can explicitly specify where the methods are to be

    Probably wouldn't work if your objects are *tied*. But that's a strange
    thing to do anyway.

    Scary code exploiting strange XS features.

    If you think writing an accessor in XS should be a laughably simple
    exercise, then please contemplate how you could instantiate a new XS
    accessor for a new hash key or array index that's only known at
    run-time. Note that compiling C code at run-time a la Inline::C is a no

    Threading. With version 1.00, a memory leak has been fixed that would
    leak a small amount of memory if you loaded "Class::XSAccessor"-based
    classes in a subthread that hadn't been loaded in the "main" thread
    before. If the subthread then terminated, a hash key and an int per
    associated method used ot be lost. Note that this mattered only if
    classes were only loaded in a sort of throw-away thread.

    In the new implementation as of 1.00, the memory will not be released
    again either in the above situation. But it will be recycled when the
    same class or a similar class is loaded again in any thread.



    Steffen Mueller, <>

    Copyright (C) 2008-2009 by Steffen Mueller

    This library is free software; you can redistribute it and/or modify it
    under the same terms as Perl itself, either Perl version 5.8 or, at your
    option, any later version of Perl 5 you may have available.