use strict; use warnings; package Clownfish; our $VERSION = '0.01'; 1; =head1 NAME Clownfish - A small OO language that forms symbiotic relationships with "host" languages. =head1 PRIVATE API Clownfish is a KinoSearch implementation detail. This documentation is partial -- enough for the curious hacker, but not a full API. =head1 DESCRIPTION =head2 Overview. Clownfish is a small language for declaring an object oriented interface and a compiler which allows classes to be implemented either in C, in a "host" language, or a combination of both. =head2 Why use Clownfish? =over =item * Clownfish-based projects give users the ability to write full subclasses in any "host" language for which a binding has been prepared. =item * Pure C Clownfish class implementations are very fast. =item * Users can perform rapid prototyping in their language of choice, then port their classes to C either for speed or to make them available across multiple language platforms. =item * =back =head2 Object Model Clownfish is single-inheritance and class based -- a minimalist design which makes it as compatible as possible with a broad range of hosts. Subclasses may be created either at compile time or at run time. =back =head2 C method invocation syntax. Methods are differentiated from functions via capitalization: Boat_capsize() is a function, Boat_Capsize() is a method. // Base method. void Boat_capsize(Boat *self) { self->upside_down = true; } // Implementing function, in Boat/Battleship.c void Battleship_capsize(Battleship *self) { // Superclass method invocation. Boat_capsize_t capsize = (Boat_capsize_t)SUPER_METHOD( BATTLESHIP, Battleship, Capsize); capsize((Boat*)self); // Subclass-specific behavior. Battleship_Sink(self); } // Implementing function, in Boat/RubberDinghy.c void RubDing_capsize(RubberDinghy *self) { // Superclass method invocation. Boat_capsize_t capsize = (Boat_capsize_t)SUPER_METHOD( RUBBERDINGHY, RubDing, Capsize); capsize((Boat*)self); // Subclass-specific behavior. RubDing_Drift(self); } =head2 Class declaration syntax [final] [inert] class CLASSNAME [cnick CNICK] [inherits PARENT] [ : ATTRIBUTE ]* { [declarations] } Example: class Boat::RubberDinghy cnick RubDing inherits Boat { public inert incremented RubberDinghy* new(); void Capsize(RubberDinghy *self); } =over =item * B - The name of this class. The last string of characters will be used as the object's C struct name. =item * B - A recognizable abbreviation of the class name, used as a prefix for every function and method. =item * B - The full name of the parent class. =item * B - An arbitrary attribute, e.g. "dumpable", or perhaps "serializable". A class may have multiple attributes, each preceded by a colon. =back =head2 Memory management At present, memory is managed via a reference counting scheme, but this is not inherently part of Clownfish. =head2 Namespaces, parcels, prefixes, and "short names" There are two levels of namespacing in Clownfish: parcels and classes. Clownfish classes intended to be published as a single unit may be grouped together using a "parcel". Parcel directives need to go at the top of each class file. parcel Crustacean cnick Crust; All symbols generated by Clownfish for classes within a parcel will be prefixed by varying capitalizations of the parcel's C-nickname or "cnick" in order to avoid namespace collisions with other projects. Within a parcel, the last part of each class name must be unique. class Crustacean::Lobster::Claw { ... } class Crustacean::Crab::Claw { ... } // Illegal, "Claw" already used "Short names" -- names minus the parcel prefix -- will be auto-generated for all class symbols. When there is no danger of namespace collision, typically because no third-party non-system libraries are being pound-included, the short names can be used after a USE_SHORT_NAMES directive: #define CRUST_USE_SHORT_NAMES The USE_SHORT_NAMES directives do not affect class prefixes, only parcel prefixes. // No short names. crust_LobsterClaw *claw = crust_LobClaw_new(); // With short names. #define CRUST_USE_SHORT_NAMES LobsterClaw *claw = LobClaw_new(); =head2 Inclusion C header code generated by the Clownfish compiler is written to a file with whose name is the same as the .cfh file, but with an extension of ".h". C code should pound-include "Crustacean/Lobster.h" for a class defined in "Crustacean/Lobster.cfh". =head1 COPYRIGHT AND LICENSE Copyright 2006-2011 Marvin Humphrey This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =cut