libs-base/Documentation

@chapter GNUstep Base Library README

@c set the vars GNUSTEP_BASE_VERSION and GCC_VERSION
@include version.texi

@include base-desc.texi

Here is some introductory info to get you started:

@section Initial reading

The file @file{doc/GNUstep-FAQ} contains a brief overview of the
library.  It also tells you where to get the most recent version.

The file @samp{NEWS} has the library's feature history.

The file @samp{INSTALL} gives instructions for installing the library.

@section Preparing to write code

The documentation isn't much to speak of so far.  Better documentation
will be forthcoming, but the library needs to settle first.  For now I
recommend skipping @file{gnustep-base.info} and reading the header files
instead.  The headers for the classes are in @file{./src/include}.

The GNUstep FAQ contains an outline of the class heirarchy, as well as a
list of the differences between GNUstep and NeXT's implementation of
OpenStep, and GNUstep's improvements over NeXT's implementation.  The
FAQ can be found in @file{doc/GNUstep-FAQ}.

Outdated, preliminary documentation is available via @samp{texinfo} in
the files @samp{gnustep-base.info} and @samp{gnustep-base.texi}.
Because texinfo doesn't yet handle @code{@@deftypemethod}, this
documentation cannot yet be compiled into more readable forms.

@section Overview of the classes

Here is partial list of non-OpenStep classes, grouped by functionality.

There are several GNU-specific protocols also.  You can recognize the
protocols by their name: they all end with ``ing''.

@itemize @bullet

@item The collection objects all conform to the @samp{Collecting}
protocol.  Reading @samp{src/include/Collecting.h} is a good place to
start.  Protocols for collections that store their contents with keys
and with indices can be found in @samp{src/incliude/KeyedCollecting.h} and
@samp{src/include/IndexedCollecting.h} respectively.  Examples of generic
collections are @samp{Set} and @samp{Bag}.  The keyed collections are
@samp{Dictionary} and @samp{MappedCollector}.  The classes @samp{Array},
@samp{Queue}, @samp{GapArray}, @samp{LinkedList}, @samp{BinaryTree},
@samp{RBTree} and @samp{SplayTree} are all indexed collections.

@item The string objects conform to the @samp{String} protocol.
@samp{CString} provides an interface to strings based on ASCII bytes,
and is currently the only concrete subclass of String.  The interface
between GNU @samp{String} and OpenStep's @samp{NSString} needs cleaning
up and will change.  For now, I recommend using @samp{NSString}.

@item The public magnitude classes are @samp{Time} and @samp{Random}.
The @samp{Random} class works in conjunction with pseudo-random number
generators that conform to the @samp{RandomGenerating} protocol.  The
conforming class @samp{RNGBerkeley} provides identical behavior to the
BSD random() function.  The class @samp{RNGAdditiveCongruential} is an
implementation of the additive congruential method.

@item Stream objects provide a consistent interface for reading and
writing bytes.  Read @samp{src/include/Stream.h} to get the general
idea.  @samp{StdioStream} objects work with files, file descriptors,
FILE pointers and pipes to/from executables.  @samp{MemoryStream}
objects work with memory buffers.

@item CStream objects provide a way to write C variables to Stream
objects.  Read @file{src/include/CStream.h} to understand the interface
of the abstract superclass.  @samp{TextCStream} writes C variables in a
human-readable ASCII format that can be manipulated with a text editor
or with your choice of text-processing programs, like @samp{awk} or
@samp{perl}.  @samp{BinaryCStream} writes C variables in a compact,
illegible stream of bytes.  @samp{TextCStream} and @samp{BinaryCStream}
each write in machine-independant formats---so you can write on one
machine architecture, and successfully read on another.
@samp{RawCStream} is like @samp{BinaryCStream} accept it is
machine-dependant; it useful for efficient Distributed Objects
connections on the same machine.

@item Coders provide a formatted way of writing Objective C objects to
CStream objects.  After a coder is initialized with a stream, the coder
can encode/decode interconnected webs of Objective C objects and C types
and successfully keep track of complex interconnections between objects.
See @samp{src/include/Coder.h} for the abstract superclass interface;
see @samp{src/include/Coding.h} for the protocol adopted by objects that
read and write themselves using coders.  @samp{Archiver} and
@samp{Unarchiver} are concrete subclasses that are used for
writing/reading with files.

@samp{Coder}s and @samp{CStream}s and @samp{Stream}s can be mixed and
matched so that programmers can choose the destination and the format
separately.

@ignore
@item @samp{Notification} 
@samp{NotificationDispatcher}
@end ignore

@item The distributed object support classes are @samp{Connection},
@samp{Proxy}, @samp{ConnectedCoder}, @samp{Port} and @samp{TcpPort}.
This version of the distributed objects only works with sockets.  A Mach
port back-end should be on the way.

See @file{doc/GNUstep-FAQ} for a detailed description of the cabilities
and non-capabilities of GNU Distributed Objects.

To begin using distributed objects, you only need to know about
@samp{Connection} class.  You can see the full (documented!) interface
in @samp{src/include/Connection.h}.  The long list of methods may be a
little daunting, but actually, a lot can be done with just a few key
methods:

@smallexample
- (Connection*) newRegisteringAtName: name
    withRootObject: anObj;
      For registering your server object with the network.

- (void) runConnection;
      For running the connection object returned by the above
      method, so that your server can start handling requests from
      clients. 

- (Proxy*) rootProxyAtName: name 
    onHost: host;
      For connecting to a remote server.  You get a proxy object for 
      the remote server object, which, for messaging purposes, you 
      can treat as if it were local.
@end smallexample

@section Where else to look

@subsection Examples

A few simple example programs can be found in @samp{examples}.
Read and enjoy.  To compile them (after having compiled the library),
type @samp{make} in the @samp{examples} directory.

@itemize @bullet

@item @samp{dictionary.m} demonstrates the basic features of the
Dictionary object.

@item @samp{stdio-stream.m} creates a StdioStream object that points to
a file, writes to the file, then reads from the file.

@item @samp{textcoding.m} shows how you can archive an object to a file 
in a human-readable text format, and then read it back in again.  This
format is handy for editing archived objects with a text editor, and is
great when you want to modify/create an archive using a scripting
language like @samp{perl} or @samp{awk}.

@item @samp{first-server.m} and @samp{first-client.m} show the
distributed object version of ``Hello, world''.

@item @samp{second-server.m} and @samp{second-client.m} contain a more
complex demonstration of distributed objects, with multiple clients,
connection delegates, and invalidation notification.

@item @samp{tcpport-server.m} and @samp{tcpport-client.m} show a simple
use of TcpPort objects.

@end itemize

@subsection Test Programs

Some of the programs I've used to test the library are in
@samp{./checks}.  Many of them are pretty messy, (desperately trying to
tickle that late night bug), but at least they show some code that works
when the library compiles correctly.  I'm looking for a volunteer to
write some nicely organized test cases using @samp{dejagnu}.  Any
takers?

@section How can you help?

@itemize @bullet

@item Read the projects and questions in the @samp{TODO} file.  If you
can volunteer for any of the projects, or if you have any useful
comments send me email!  <mccallum@@gnu.ai.mit.edu>

@item
Give me feedback!  Tell me what you like; tell me what you think
could be better.  Send me bug reports.

@item
Donate classes.  If you write classes that fit in the libgnustep-base
framework, I'd be happy to include them.

@end itemize

@example
Happy hacking!
       Andrew McCallum
       mccallum@@gnu.ai.mit.edu
@end example