1 The Glasgow Haskell Compiler -- version 0.16
2 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4 The second public release of the Glasgow Haskell Compiler is now
5 available (GHC, version 0.16). Binaries (recommended) and source are
6 freely available by FTP; details appear below.
8 GHC 0.16 is still alpha-quality software. This release in an interim
9 measure, not as solid as I would prefer. However, a lot has gone in
10 since December. The profiling system is Way Cool. The compiler now
11 has a strictness analyser and an update analyser. Compiled programs
12 tend to run faster. Compilation speed is worse. Bugs remain, but
13 they tend to be work-around-able.
15 To run this release, you need a Sun4 or Sun3, probably with 16+MB
16 memory, and GNU C (gcc), version 2.1 or greater, and "perl".
18 This system can be built from source using: itself (most likely to
19 succeed), the previous GHC release (0.10) [least likely], or the
20 Chalmers HBC compiler [in-between]. Please see the appropriate
21 documentation for details.
23 Please report bugs to glasgow-haskell-bugs@dcs.glasgow.ac.uk and
24 direct general queries to glasgow-haskell-request@<same>.
27 (typist for the AQUA [formerly GRASP] project)
29 ....................................................................
31 Why a Haskell programmer might want to use GHC
32 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
33 * GHC provides an extensible I/O system, based on a "monad" [1]. (The
34 standard Haskell I/O system is built on this foundation.)
36 * A number of significant language extensions are implemented:
37 - Fully fledged unboxed data types [2].
38 - Ability to write arbitrary in-line C-language code, using
39 the I/O monad to retain referential transparency.
40 - Incrementally-updatable arrays, also embedded in a monad.
41 - Mutable reference types.
43 * A new profiling system is supplied, which enables you to find out
44 which bits of your program are eating both *time* and the *space* [3].
46 * By default, the system uses a generational garbage collector which
47 lets you run programs whose live data is significantly larger than
48 the physical memory size before thrashing occurs. (Conventional
49 2-space GC starts thrashing when the live data gets to about half
50 the physical memory size.)
52 * Good error messages. Well, fairly good error messages. Line
53 numbers are pretty accurate, and during type checking you get
54 several (accurate) error reports rather than just one.
56 * Performance: programs compiled with GHC "often" beat
57 Chalmers-HBC-compiled ones. If you find programs where HBC wins,
58 please report it to us, as a bug :-).
60 Why a functional-language implementor might want to use GHC
61 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
62 * We have tried very hard to write the compiler in a modular and
63 well-documented way, so that other researchers can modify and extend
64 it. One of our goals is specifically to provide a framework to
65 support others' work. Several people are already using it in this
68 * Highly configurable runtime system. Heavy use of C macros means
69 that you can modify much of the storage representation without
70 telling the compiler. For example, the system comes with 4
71 different garbage collectors! (all working)
73 * Internals: extensive use of the second-order lambda calculus as an
74 intermediate code; the Spineless Tagless G-machine as evaluation
77 * Various performance-measurement hooks.
81 * No interactive system. This is a batch compiler only. (Any
84 * Compiler is greedy on resources. Going via C doesn't help here.
86 * This system should run on any Unix box. We haven't had time to do
87 any non-Sun ports. Help or prodding welcome.
91 All these papers come with the distribution [in ghc/docs/papers].
93 [1] "Imperative functional programming", Peyton Jones & Wadler, POPL '93
95 [2] "Unboxed data types as first-class citizens", Peyton Jones &
98 [3] "Profiling lazy functional languages", Sansom & Peyton Jones,
101 [4] "Implementing lazy functional languages on stock hardware", Peyton
102 Jones, Journal of Functional Programming, Apr 1992
106 This release is available, in whole or in part, from the usual Haskell
107 anonymous FTP sites, in the directory pub/haskell/glasgow:
109 ftp.dcs.glasgow.ac.uk (130.209.240.50)
110 ftp.cs.chalmers.se (129.16.225.66)
111 nebula.cs.yale.edu (128.36.13.1)
113 We are mirrored by src.doc.ic.ac.uk, in
114 computing/programming/languages/haskell/glasgow, and you can get files
115 from there by every means known to humanity.
117 These are the available files (.Z for compressed, .gz for gzipped) --
118 some are `on demand', ask if you don't see them:
120 ghc-0.16-bin-sun4.tar.{Z,gz} A binary distribution -- avoid compiling
121 altogether! For SunOS 4.1.x; assumes you have
122 GNU C (gcc) version 2.x around...
124 ghc-0.16-src.tar.gz The basic source distribution; about 3MB.
126 ghc-0.16-hi-files-{hbc,ghc-0.10}.tar.gz
127 Interface files for the compiler proper
128 (ghc/compiler/*/*.hi), to be used if booting
129 with either HBC or GHC version 0.10. (The
130 distributed .hi files assume GHC version
133 ghc-0.16-hc-files.tar.gz The intermediate C files for the compiler
134 proper, the prelude, and `Hello, world'.
137 ghc-0.16-patch-* Patches to the original distribution. There
138 are none to start with, of course, but there
139 might be by the time you grab the files.
140 Please check for them.
142 There are no diffs from version 0.10, as they would be laughably huge.
144 Once you have the distribution, please follow the pointers in the
145 ghc/README file to find all of the documentation in and about this