* The Class Library
The Class Library should be compatible with Microsoft's .NET
implementation.
Please see the Class Status
page for a status of who is working on which classes.
We will write as much code as possible in C#. We may need to
interface with code written in C to gain access to the
functionality of libraries like libart, Gtk+, and libc.
** Contributing
We welcome contributions to the the Class Library. To get
started, check the status page for information about which
APIs are being worked on, and how to get in touch with
individual maintainers.
If you want to work on a class, first check the Classes Distribution to see if it is
not implemented yet, if not, check the Class Status to see if someone is
already working on it, and maybe contact them.
If nobody is working on it, mail mono-list@ximian.com
with the class you want to implement and CC miguel@ximian.com.
You can also track live the activities of the Mono CVS module
by subscribing to the mono-cvs-list
** Layout
The Class Library resides in the `mcs' module in the directoy
`class'.
Each directory in the directory represents the assembly where
the code belongs to, and inside each directory we divide the
code based on the namespace they implement.
There are two cases when we should consider portability: when
we are dealing with a couple of classes only that differ from
system to system (Consider System.Net and System.IO for Win32
and Unix). In those cases we will just place the files for
example on corlib/System/System.IO/Unix-Console.cs and
corlib/System/System.IO/Win32-Console.cs.
For classes that might differ more (for example, the
implementation of Windows.Forms), we might have different
directories altogether: System.Windows.Forms/Win32,
System.Windows.Forms/Gtk+ and
System.Windows.Forms/Cocoa.
** Using existing components from GNOME.
Our current plan is to implement the GUI tools on top of
Gtk+. The only obstacle here is that applications from Windows
might expect to be able to pull the HWND property from the
widgets and use PInvoke to call Windows functions.
** Class Library and Win32 dependencies.
There are a few spots where the Win32 foundation is exposed to
the class library (for example, the HDC and HWND properties in
the GDI+). Casual inspection suggests that these can be
safely mapped to Gdk's GC and GdkWindow pointers without
breaking anything.
The only drawback is that support for PInvoke of Win32 code
won't be available. An alternate solution would be to use
portions of Wine, or even to use Wine as our toolkit.
*** Initial GDI+ and WinForms implementation
The initial implementation will use Gtk+ as the underlying
toolkit. Since GTK+ has already been ported to many windowing
systems other than X (including frame buffer, Win32, and BeOS)
its use should cover most applications for most users.
*** Database access
We will implement ADO.NET functionality by reusing GNOME-DB. This is an ideal
choice, since GNOME-DB was implemented precisely to provide an
ADO-like system for GNOME.
*** Component Integration
We will provide a new namespace to use GNOME specific features
as well as a namespace to host Bonobo interfaces and classes
in Mono.
** Licensing
The class library will be licensed under the terms of the GNU
LGPL. Some people have pointed out that the plain LGPL is
troublesome for embedded use of the Mono class libraries. So
we are considering to use the GPL with a special exception
(like the GNU
Classpath project did.
The exception to the GPL would be:
The library is distributed under the terms of the GNU General
Public License with the following exception:
If you link this library against your own program, then you do not
need to release the source code for that program. However, any
changes that you make to the library itself, or to any native
methods upon which the library relies, must be re-distributed in
accordance with the terms of the GPL.
If you are going to contribute, please keep in mind that we
might require you to agree that Ximian might adjust the
license to enable the use of the class libraries on embedded
systems or to develop proprietary applications using Mono.
We suggest that you assign the copyright of your work to the
GNOME Foundation or the Free Software Foundation to simplify
defending the code in case it is used inappropiately.
** Class Library testing
We need to write regression tests that will verify
the correctness of the class library, compiler, and JIT
engine.
Please write your regression tests using NUnit
** Coding conventions
Please follow the conventions on the ECMA specification (On
the Annex Partition) for your coding your libraries.
Use 8 space tabs for writing your code (hopefully we can keep
this consistent). If you are modifying someone else's code, try
to keep the coding style similar.
For a rationale on 8 space tabs, read Linus Torvald's Coding
Style guidelines in the Linux kernel source for a rationale.
*** Missing implementation bits
If you implement a class and you are missing implementation bits,
please put in the code the word "TODO" and a description of what
is missing to be implemented.
*** Tagging buggy code
If there is a bug in your implementation tag the problem by using
the word "FIXME" in the code, together with a description of the
problem.
Do not use XXX or obscure descriptions, because otherwise people
will not be able to understand what you mean.
*** Tagging Lame specs
Sometimes the specification will be lame (consider Version.ToString (fieldCount)
where there is no way of knowing how many fields are available, making the API
not only stupid, but leading to unreliable code).
In those cases, use the keyword "LAMESPEC".
** FAQ
Frequently asked questions about the class library:
Q: I am writing a new class that overrides one of the system classes,
and I am getting a 1595 warning from the compiler. Should we use a
different namespace?
A: There is a quick solution to the problem, you can pass the command
line argument /nowarn:1595 and this will effectively let you use
your implementation of the code, while overriding the ones from the
system assemblies.