@c =================================================================== @c
@c    serrano/prgm/project/bigloo/manuals/custom.texi                  @c
@c    ------------------------------------------------------------     @c
@c    Author      :  Manuel Serrano                                    @c
@c    Creation    :  Wed Aug  7 21:01:03 2002                          @c
@c    Last change :                                                    @c
@c    Copyright   :  2002 Manuel Serrano                               @c
@c    ------------------------------------------------------------     @c
@c    Custom types.                                                    @c
@c =================================================================== @c

@c ------------------------------------------------------------------- @c
@c    Libraries                                                        @c
@c ------------------------------------------------------------------- @c
@node Extending the Runtime System, DSSSL Support, Bigloo Libraries, Top
@comment  node-name,  next,  previous,  up
@chapter Extending the Runtime System
@cindex Custom types

@emph{Custom Types} types are not documented yet. This facility enables
extension to the standard Bigloo runtime system. The current implementation
of custom types is subject to change. It will be documented in coming
releases.

@c  @emph{Custom Types} enable extensions to the standard Bigloo runtime  @c
@c  system.  @emph{Custom Types} are primitive Bigloo types as all the  @c
@c  native Bigloo types (such as*}ode{pair}, @code{procedure}, ...). For  @c
@c  the Scheme point of view @emph{Custom Types} are regular native types.  @c
@c  @emph{Custom Types} can be defined in the user C code or Java code.  @c
@c                                                                     @c
@c  {*-- Custom Types ---------------------------------------------------*}  @c
@c  @section Custom Types                                              @c
@c                                                                     @c
@c  @subsection Creating a Custom Type                                 @c
@c                                                                     @c
@c  @subsection Configuring a Custom Type                              @c
@c                                                                     @c
@c  @subsection Custom Types vs Foreign Types                          @c
@c                                                                     @c
@c  The Bigloo runtime system supports @emph{Foreign Types}. These are  @c
@c  either defined in*}ode{extern} or @code{java} clauses. In some     @c
@c  situations one may wonder when it is appropriate to create a       @c
@c  @emph{Custom Type} instead of a @emph{Foreign Type}. The rule of thumb  @c
@c  is that @emph{Foreign Types} are sufficient when the Scheme code is  @c
@c  not directly manipulating (reading, printing, storing) the foreign  @c
@c  values. When a foreign value only transit trough some Scheme       @c
@c  functions, @emph{Foreign Types} are sufficient. On the other hand,  @c
@c  when the Scheme treatment of these foreign values become more      @c
@c  important, it is, in general, the time to consider @emph{Custom    @c
@c  Types}.                                                            @c
@c                                                                     @c
@c  {*-- An example of extension ----------------------------------------*}  @c
@c  @section An example of runtime system extension                    @c
