From: simonpj@dcs.gla.ac.uk (simonpj)
Newsgroups: comp.lang.functional
Subject: Glasgow Haskell, version 0.10, now available
Date: 11 Dec 92 21:29:18 GMT
Organization: Glasgow University Computing Science Dept.
Return-Path: <simonpj@dcs.gla.ac.uk>
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		  The Glasgow Haskell Compiler
		  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We are happy to announce the first full release of the Glasgow Haskell
Compiler (GHC, version 0.10).  It is freely available by FTP; details
appear below.

To run this release, you need a Sun4, probably with 16+MB memory, and
GNU C (gcc), version 2.1 or greater, and "perl".  If building from
source, you will need Chalmers HBC, version 0.998.x.

We hope you enjoy this system, and we look forward to hearing about
your successes with it!  Please report bugs to
glasgow-haskell-bugs@dcs.glasgow.ac.uk and direct general queries to
glasgow-haskell-request@<same>.

Simon Peyton Jones
(and his GRASPing colleagues)

Why a Haskell programmer might want to use GHC
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Almost all of Haskell is implemented.  In particular, the full range
  of data types is supported: arbitrary precision integers, rationals,
  double-precision floats, and "real" arrays with O(1) access time.
  (The release notes list all unimplemented language features.)

* An extensible I/O system is provided, based on a "monad" [1]. (The
  standard Haskell I/O system is built on this foundation.)

* A number of significant language extensions are implemented:
	- Fully fledged unboxed data types [2].
	- Ability to write arbitrary in-line C-language code, using
	  the I/O monad to retain referential transparency.
	- Incrementally-updatable arrays, also embedded in a monad.
	- Mutable reference types.

* By default, the system uses a generational garbage collector which
  lets you run programs whose live data is significantly larger than
  the physical memory size before thrashing occurs.  (Conventional
  2-space GC starts thrashing when the live data gets to about half
  the physical memory size.)

* A new profiling system is supplied, which enables you to find out which
  bits of your program are eating both *time* and the *space* [3].

* Good error messages.  Well, fairly good error messages.  Line
  numbers are pretty accurate, and during type checking you get
  several (accurate) error reports rather than just one.

* Performance: programs compiled with GHC "usually" beat
  Chalmers-HBC-compiled ones.  If you find programs where HBC wins,
  send them to us :-).

* We have a pretty good test suite, and this version passes
  practically all of it.  (Yes, it can compile itself, too.) We hope
  you will find the system to be robust.

Why a functional-language implementor might want to use GHC
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* We have tried very hard to write the compiler in a modular and
  well-documented way, so that other researchers can modify and extend
  it.  One of our goals is specifically to provide a framework to
  support others' work.  Several people are already using it in this
  way.

* Highly configurable runtime system.  Heavy use of C macros means
  that you can modify much of the storage representation without
  telling the compiler.  For example, the system comes with 4
  different garbage collectors! (all working)

* Internals: extensive use of the second-order lambda calculus as an
  intermediate code; the Spineless Tagless G-machine as evaluation
  model [4].

* Various performance-measurement hooks.

Main shortcomings
~~~~~~~~~~~~~~~~~
* No interactive system.  This is a batch compiler only.  (Any
  volunteers?)

* Compiler is greedy on resources.  Going via C doesn't help here.

* This system should run on any Unix box.  We haven't had time to do
  any non-Sun4 ports.  Help or prodding welcome.

References
~~~~~~~~~~
All these papers come with the distribution [in ghc/docs/papers].

[1] "Imperative functional programming", Peyton Jones & Wadler, POPL '93

[2] "Unboxed data types as first-class citizens", Peyton Jones &
    Launchbury, FPCA '91

[3] "Profiling lazy functional languages", Sansom & Peyton Jones,
    Glasgow workshop '92

[4] "Implementing lazy functional languages on stock hardware", Peyton
    Jones, Journal of Functional Programming, Apr 1992

How to get it
~~~~~~~~~~~~~
This release is available, in whole or in part, from the usual Haskell
anonymous FTP sites, in the directory pub/haskell/glasgow:

	nebula.cs.yale.edu     (128.36.13.1)
	ftp.dcs.glasgow.ac.uk  (130.209.240.50)
	animal.cs.chalmers.se  (129.16.225.66) [initially in pub/incoming]

(Beleaguered NIFTP users within the UK can get the same files from
Glasgow by using a <FP>/haskell/glasgow prefix, instead of
pub/haskell/glasgow.  Also, we are mirrored by src.doc.ic.ac.uk, in
languages/haskell/glasgow, and you can get files from there by every
means known to humanity.)

These are the available files:

ghc-0.10-src.tar.Z	The basic source distribution; assumes you
			will compile it with Chalmers HBC, version
			0.998.n, on a Sun4, for which you have GNU C
			(gcc) version 2.1 or greater.  About 3MB.

ghc-0.10-bin-sun4.tar.Z	A binary distribution -- avoid compiling
			altogether!  For SunOS 4.1.x; assumes you
			have GNU C (gcc) version 2.x around...

ghc-0.10-patch-*	Patches to the original distribution.  There
			are none to start with, of course, but there
			might be by the time you grab the files.
			Please check for them.

Once you have the distribution, please follow the pointers in the
ghc/README file to find all of the documentation in and about this
release.
Newsgroups: comp.lang.pop