Author image Marvin Humphrey
and 1 contributors


Boilerplater - Bolt OO functionality onto C.


Boilerplater is an implementation detail. This documentation is partial -- enough for the curious hacker, but not a full API.



Boilerplater is a small language for describing an object oriented interface, and a compiler which generates some "boilerplate" header code allowing that interface to be used from C.

Object Model

  • Single inheritance.

  • Method dispatch using virtual tables.

Method invocation syntax.

Methods are differentiated from functions via capitalization: Dog_say_hello is a function, Dog_Say_Hello is a method.

    /* Implementing function, in Dog/Chihuahua.c */
    Chihuahua_say_hello(Chihuahua *self) 
        printf("Yap! Yap! Yap!\n");

    /* Implementing function, in Dog/SaintBernard.c. */
    StBernard_say_hello(SaintBernard *self)
        printf("Rooorf! Rooorf!\n");

    /* Invoke Say_Hello method for several Dog objects. */
    DogPack_greet(DogPack *self)
        u32_t i;
        for (i = 0; i < self->pack_size; i++) {

Class declaration syntax

    [final] [static] class CLASSNAME [cnick CNICK] [extends PARENT] {


    class Dog::SaintBernard cnick StBernard extends Dog {
        void Say_Hello(SaintBernard *self);
  • CLASS_NAME - The name of this class. The last string of characters will be used as the objects C struct name.

  • CNICK - A recognizable abbreviation of the class name, used as a prefix for every function and method.

  • PARENT - The full name of the parent class.

Memory management

At present, KinoSearch manages memory via a reference counting scheme, but this is not inherently part of Boilerplater.

Namespaces, parcels, prefixes, and "short names"

There are two levels of namespacing in Boilerplater: parcels and classes.

Boilerplater classes intended to be published as a single unit may be grouped together using a "parcel" (akin to a "package" in Java). Parcel directives need to go at the top of each class file.

    parcel Crustaceans cnick Crust;

All symbols generated by Boilerplater 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:


The USE_SHORT_NAMES directives do not affect class prefixes, only package prefixes.

    /* No short names. */
    crust_Lobster *lobster = crust_Lobster_new();
    /* With short names. */
    Lobster *lobster = Lobster_new();


The boilerplate code is written to a file with whose name is the same as the .bp file, but with an extension of ".h". C code should pound-include "Boiler/Util/Foo.h" for a class defined in "Boiler/Util/Foo.bp".


Copyright 2006-2009 Marvin Humphrey

This program is free software; you can redistribute it and/or modify under the same terms as Perl itself.