<chapter id="miscellaneous">
<title>Miscellaneous</title>

<sect1 id="history">
<title>Hugs 98 release history</title>

<para>
These are the release notes for the program since it was renamed Hugs 98,
reflecting substantial compliance with Haskell 98
(though with numerous optional extensions).
Archives of older versions of
<ulink url="http://www.cse.ogi.edu/~mpj/goferarc/index.html">Gofer</ulink>
and
<ulink url="http://www.cse.ogi.edu/~mpj/hugsarc/index.html">Hugs</ulink>
are still available from Mark Jones's web page.
</para>

<sect2>
<title>January 1999 (Beta release)</title>

<para>
Headline news for this release includes:
</para>

<itemizedlist>
<listitem><para>
Hugs goes Haskell 98!  Hugs 98 is the first released Haskell system
to support the new standard for Haskell 98.
</para></listitem>

<listitem><para>
Hugs goes Open Source!  Hugs 98 is the first Hugs release to be
distributed as Open source software.  Responding to requests from
users, this relaxes the conditions of use and distribution of
previous releases, and will hopefully make it easier to use Hugs
for a wide range of projects.
</para></listitem>
</itemizedlist>

<para>
This release of Hugs also merges the features of several earlier releases
into one single system. This includes:
</para>

<itemizedlist>
<listitem><para>
The module system and dynamic linking facilities of Hugs 1.4 (June 1998);
</para></listitem>

<listitem><para>
The type system extensions
(<link linkend="multi-param">multi-parameter classes</link>,
<link linkend="trex">TREX</link>,
<link linkend="rank-2-types">rank-2 polymorphism</link>,
<link linkend="existential-quantification">existentials</link>,
etc.) of Hugs 1.3c p1 (March 1998);
</para></listitem>

<listitem><para>
New features and modifications to support the draft Haskell 98 standard;
</para></listitem>

<listitem><para>
A whole range of bug fixes and additions for all of the above.
</para></listitem>
</itemizedlist>

</sect2>

<sect2>
<title>May 1999</title>

<para>
This release is largely conformant with Haskell 98, including
monad and record syntax, newtypes, strictness annotations, and
modules.  In addition, it comes packaged with the libraries defined
in the most recent version of the Haskell Library Report and with
extension libraries that are compatible with GHC 3.0 and later.
</para>

<para>
Additional features of the system include:
</para>

<itemizedlist>
<listitem><para>
<quote>Import chasing</quote>: a single module may be loaded, and Hugs will
chase down all imports as long as module names are the same as
file names and the files are found in the current path.
</para></listitem>

<listitem><para>
A simple GUI for Windows to facilitate program development.
</para></listitem>

<listitem><para>
Library extensions to support concepts such as concurrency,
mutable variables and arrays, monadic parsing, tracing (for
debugging), graphics, and lazy state threads.
</para></listitem>

<listitem><para>
A Win32 library for complete access to windows, graphics, and
other important OS functionalities and a graphics library for
easy access to Win32 graphics.
</para></listitem>

<listitem><para>
A <quote>foreign interface</quote> mechanism to facilitate interoperability
with C.
</para></listitem>
</itemizedlist>

</sect2>

<sect2>
<title>November 1999</title>

<itemizedlist>
<listitem><para>
BSD-style license (replacing the Artistic License)
</para></listitem>

<listitem><para>
new commands
<link linkend="browse-command"><command>:browse</command></link> and
<link linkend="version-command"><command>:version</command></link>
</para></listitem>

<listitem><para>
experimental multi-instance resolution and <command>:xplain</command> command
</para></listitem>

<listitem><para>
<link linkend="functional-dependencies">functional dependencies</link>
</para></listitem>

<listitem><para>
zero parameter type classes
</para></listitem>

<listitem><para>
better handling of overlapping instances
</para></listitem>

<listitem><para>
various bug fixes
</para></listitem>
</itemizedlist>

<!-- the next two were bugfix releases of Nov99, so make them sub -->
<!-- sections. -->
<sect3>
<title>February 2000</title>

<para>
This is purely a bug-fix release of Hugs98 November 99.
It fixes the following problems:
</para>

<itemizedlist>
<listitem><para>
If you defined an instance which inherited a method via a
superclass, hugs would go into an infinite loop.  Fortunately,
most people weren't doing this (except Chris Okasaki...).
</para></listitem>

<listitem><para>
There were a couple of holes in the implementation of implicit parameters
(<quote><literal>with</literal></quote> wasn't always being scoped properly,
sometimes capturing implicit parameters outside of its scope).
</para></listitem>

<listitem><para>
Functional dependencies weren't being properly propagated in
some cases with derived instances
(<quote><literal>instance P ... =&gt; Q ...</literal></quote>).
</para></listitem>
</itemizedlist>

</sect3>

<sect3>
<title>July 2000</title>

<para>
This is purely a bug-fix release of Hugs98 February 2000.
</para>

</sect3>

</sect2>

<sect2>
<title>February 2001</title>

<para>
This is a major release that incorporates bug fixes as well as
several new features and enhancements that have been developed for
Hugs over the last year. It is announced with the intention that
it will remain a stable and lightweight implementation of Haskell 98
+ extensions for some considerable time.
</para>

<para>
A list of the most important new features looks as follows:
</para>

<itemizedlist>
<listitem><para>
A Foreign Function Interface closely modelled after the one
provided by GHC.
</para></listitem>

<listitem><para>
Built-in, <link linkend="observe">Hood-like debugging support</link>.
</para></listitem>

<listitem><para>
<link linkend="zip-comprehension">Parallel list comprehensions</link>,
a.k.a. zip-comprehensions.
</para></listitem>

<listitem><para>
A new syntax for <link linkend="recursive-do">recursive monad bindings</link>.
</para></listitem>

<listitem><para>
A new GUI under Windows that doesn't consume all CPU time.
</para></listitem>

<listitem><para>
Support for the MacOS platform integrated into the main distribution.
</para></listitem>

<listitem><para>
Corrections of all bugs reported for the January 2001 beta
release.
</para></listitem>
</itemizedlist>

</sect2>

<sect2>
<title>December 2001</title>

<para>
The most important features of this new release are:
</para>

<itemizedlist>
<listitem><para>
The incompatibilities between Hugs and the Haskell Graphics Library
have been fixed, and binaries for the HGL are now available on the
Hugs download page.
</para></listitem>

<listitem><para>
The missing standard libraries <literal>Directory</literal>,
<literal>CPUTime</literal>, <literal>Time</literal> and
<literal>Locale</literal>
have been added along with a complete implementation of
Haskell 98 <literal>IO</literal>.
</para></listitem>

<listitem><para>
Hugs is now delivered with most of the <literal>hslibs</literal> libraries
installed in the <literal>lib/exts/</literal> directory.
The added modules cover the <literal>Edison</literal>,
<literal>Parsec</literal>, <literal>HaXml</literal>,
<literal>QuickCheck</literal>, <literal>concurrent</literal>,
<literal>monad</literal> and <literal>html</literal> subdirectories
of <literal>hslibs</literal>.
</para></listitem>

<listitem><para>
The <command>:set</command> command now refuses the user to set a module
search path that doesn't contain the <literal>Prelude</literal>.
This is to protect users from accidentally rendering their Hugs setups
unusable, especially on Windows machines where the options persist
in the Registry.
</para></listitem>

<listitem><para>
MacOS X is now one of the supported unix ports, with pre-built
binaries available on the download page.
</para></listitem>

<listitem><para>
Experimental support is provided for hierarchical module names,
where a module name <literal>A.B.C</literal> is mapped onto the file path
<literal>A/B/C</literal>{<literal>.hs</literal>,<literal>.lhs</literal>}
and appended to each of the path prefixes in
<literal>HUGSPATH</literal> until the name of a readable file is found.
</para></listitem>
</itemizedlist>

</sect2>

<sect2>
<title>November 2002</title>

<para>
Feature highlights of this new release are:
</para>

<itemizedlist>
<listitem><para>
Much improved FFI support (contributed by Alastair Reid), bringing
Hugs really very close to the Haskell FFI specification.
</para></listitem>

<listitem><para>
Adoption of a significant subset of GHC's hierarchical libraries
(contributed by Ross Paterson).
</para></listitem>

<listitem><para>
An (allegedly) complete implementation of the Haskell98 module
system (Sigbjorn Finne).
</para></listitem>

<listitem><para>
Numerous bug fixes since the previous major release in Dec 2001.
</para></listitem>
</itemizedlist>

</sect2>

<sect2>
<title>November 2003</title>

<para>
There has been substantial internal restructuring.
In addition to numerous bug fixes, user-visible changes include:
</para>

<itemizedlist>
<listitem><para>
The beginnings of a User's Guide (though still incomplete).
</para></listitem>

<listitem><para>
The <literal>Double</literal> type is now double-precision
on most architectures.
</para></listitem>

<listitem><para>
Hugs now relies on the same hierarchical libraries as GHC and Nhc98,
and provides almost all of them.
For now, compatibility with the old libraries is provided by stub
modules, but users are encouraged to migrate to the new libraries.
</para></listitem>

<listitem><para>
Full support for imprecise exceptions (but not asynchronous ones).
Most runtime errors are now reported by applying <function>print</function>
to an <literal>Exception</literal>
(formerly the built-in printer was applied to the faulty redex).
</para></listitem>

<listitem><para>
Integrated .NET support (on Windows platforms).
</para></listitem>

<listitem><para>
The <option>-e</option>, <option>-f</option>, <option>-i</option>,
<option>-N</option>, <option>-W</option> and <option>-X</option> options
and the <command>:project</command> command have been removed.
</para></listitem>

<listitem><para>
A searchpath may include an entry of the form
<quote><replaceable>directory</replaceable><literal>/*</literal></quote>,
meaning all the immediate subdirectories of <replaceable>directory</replaceable>
(see <xref linkend="option-search-path"/>).
</para></listitem>
</itemizedlist>

</sect2>

<sect2>
<title>March 2005</title>

<para>
This release is primarily targeted at Unix systems to gain experience
with new features.
The new Cabal-based library build system has the potential to make
building on Windows easier, but it's not there yet.  Volunteers welcome.
</para>

<para>
In addition to numerous bug fixes, user-visible changes include:
</para>

<itemizedlist>

<listitem><para>
The default current module is now the empty module <literal>Hugs.Base</literal>
instead of the <literal>Prelude</literal>
(see <xref linkend="module-commands"/>).
</para></listitem>

<listitem><para>
The <literal>Char</literal> type and the <literal>Char</literal> module
now support Unicode as specified in the Haskell 98 Report
(contributed by Dmitry Golubovsky).
Character oriented I/O uses a byte encoding of characters determined
by the current locale (see <xref linkend="locale"/>).
</para></listitem>

<listitem><para>
The new <link linkend="option-split-options"><option>-X</option></link> option
can be used to group several options into one argument.
This is now needed for executable <command>runhugs</command> scripts
(using the Unix <quote><literal>#!</literal></quote> feature)
that require two or more options (see <xref linkend="runhugs"/>).
</para></listitem>

<listitem><para>
The syntax of the <command>ffihugs</command> command has changed
(see <xref linkend="ffihugs"/>).
The <option>+G</option> and <option>+L</option> options are gone,
and a new <option>-i</option> option can be used to specify include files.
</para></listitem>

<listitem><para>
Hugs now has basic support for the
<ulink url="http://www.haskell.org/cabal/">Cabal</ulink> packaging system
(see <xref linkend="packages"/>).
</para></listitem>

</itemizedlist>

</sect2>

<sect2>
<title>May 2006</title>

<itemizedlist>

<listitem><para>
The default current module is now the empty module <literal>Hugs</literal>
(see <xref linkend="module-commands"/>).
</para></listitem>

<listitem><para>
The compatibility libraries are no longer included on the default search path.
You can access them by adding <quote><literal>{Hugs}/oldlib</literal></quote>
to the search path (see <xref linkend="option-search-path"/>),
but they will be removed in the next release.
</para></listitem>

<listitem><para>
Rewritten graphical Windows interface
(contributed by Neil Mitchell;
see <xref linkend="winhugs"/>).
</para></listitem>

<listitem><para>
New <link linkend="main-command"><command>:main</command></link> command
(contributed by Neil Mitchell).
</para></listitem>

</itemizedlist>

<sect3>
<title>September 2006</title>

<para>
This is a minor release fixing bugs in the May 2006 release,
and including updated libraries matching those of GHC 6.6.
</para>

<itemizedlist>

<listitem><para>
The built-in printer is now less verbose, making pattern-match exceptions
more readable.
</para></listitem>

</itemizedlist>

</sect3>

</sect2>

</sect1>

</chapter>
