jwp@cacs.usl.edu (Jason W. Pritchard) (01/10/91)
Are there any public domain versions of Miranda??? If so, what are the ftp sites??? We have Sun, Vax and Pyramid Technolgies machines running Berkley Unix 4.3 (and a few other versions). Any help would be appreciated. -Jason
torbenm@diku.dk (Torben [gidius Mogensen) (01/10/91)
jwp@cacs.usl.edu (Jason W. Pritchard) writes: > Are there any public domain versions of Miranda??? There most definitely is not. Miranda(TM) is a product from Research Software Limited (or is that Limited Research Software? :-) and they will happily sue anyone else selling a language with that name. Orwell is virtually identical to Miranda. I don't know if it is public domain, but it is definitely cheaper and faster than Miranda(TM). A Miranda like language called RUFL was recently announced available (on diskettes and soon by FTP) by cspw@quagga.ru.ac.za in this group. Here at DIKU we have a compiler for a large subset of a Miranda like language that compiles into Scheme. The compiler is based on partial evaluation of an interpreter written in Scheme. It has, as yet, no really good user interface. Torben Mogensen (torbenm@diku.dk)
kinnersley@kuhub.cc.ukans.edu (Bill Kinnersley) (01/11/91)
In article <1991Jan10.111559.12440@odin.diku.dk>, torbenm@diku.dk (Torben [gidius Mogensen) writes: : [mentions several Miranda-like languages] : I've had exposure to some other functional languages (like ML) but not Miranda. Other than being lazily evaluated, what sets it apart? What makes a language Miranda-like? -- --Bill Kinnersley
sestoft@diku.dk (Peter Sestoft) (01/11/91)
kinnersley@kuhub.cc.ukans.edu (Bill Kinnersley) writes: >What makes a language Miranda-like? The main difference between Miranda (TM) and Lazy ML is the syntax. In Miranda the program lay-out has semantics: the off-side rule determines where an expression ends, whereas (Lazy) ML has more Pascal-like conventions, using semicolons similar punctuation. (The off-side rule was suggested by Peter Landin in the sixties). This, and the "list comprehension" notation makes (small) Miranda programs very beautiful. On the other hand, Miranda lacks the modules (structures) and functors of Standard ML. Also, Miranda is implemented by compilation to a fixed set of combinators which are then interpreted, and therefore execution is very slow. But the compiler gives much better (more comprehensible) type error messages than the Chalmers Lazy ML compiler. The off-side rule determines that the definition of g is a local to f in f x = g z where z = 5 g y = 7 but global in f x = g z where z = 5 g y = 7 List comprehensions allow one to write concisely things that would have to be expressed with combinations of map, filter, and concat, otherwise. Thus [f x | xs <- xss; x <- xs; p x] corresponds to concat (map ((map f) . (filter p)) xss) which is less comprehensible (to me, at least). Peter -- Peter Sestoft * sestoft@diku.dk * DIKU, Department of Computer Science University of Copenhagen, Universitetsparken 1, DK-2100 Copenhagen O, Denmark Tel: +45 31 39 64 66 * Direct: +45 31 39 33 11/406 * Fax: +45 31 39 02 21
lambert@spectrum.cs.unsw.oz.au (Tim Lambert) (01/12/91)
>>>>> On 11 Jan 91 10:00:48 GMT, sestoft@diku.dk (Peter Sestoft) said: > But the [Miranda] > compiler gives much better (more comprehensible) type error messages > than the Chalmers Lazy ML compiler. My God! What must Chalmers error messages be like! Miranda abs -3 type error in expression cannot unify num->num with num Tim
rst@cs.hull.ac.uk (Rob Turner) (01/14/91)
Bill Kinnersley writes (about Miranda (TM :-)):
>Other than being lazily evaluated, what sets it apart?
Good question. I would assume you believe there are some wonderful
facilities in Miranda which just *cannot* be obtained in any of the
public domain functional languages. Never having used Miranda (TM),
but after reading lots about it in various books, I conclude that
there is nothing to set Miranda (TM) apart from languages such as SML
and Haskell. The people at Research Software Ltd *must* believe that
they have a unique language, there is no other explanation for their
reason to charge people for it. Maybe it runs a lot faster than SML
and Haskell, although I find this hard to believe as it has lazy
semantics.
Of course there is the argument of support and maintenance, which is
better provided for in commercial products. But are there really lots
of people using Miranda for large scale projects which depend
critically on a first class support (and who can't program their way
around any bugs :-))?
I would like to discover just how many copies of Miranda (TM) have
been sold. It would make interesting reading. Better still, what are
the figures for the number of users of all "modern" functional
languages, e.g. SML, Haskell, Miranda (TM), Hope, Orwell.
Rob