Re: [Haskell-cafe] Re: What's the deal with Clean?
Stephen Tetley schrieb: Why speak nonsense when you can test it? // module nonsense import StdEnv nonsense = map ((^) 2) Start = nonsense [1,2,3] // Running gives: [2,4,8] I think they wanted square numbers, not powers of two. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: What's the deal with Clean?
Hi Henning I spotted that (and also that Clean doesn't have sections) after my blood pressure returned to normal. Best wishes Stephen [2,4,8] I think they wanted square numbers, not powers of two. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: What's the deal with Clean?
L Spice jadenb1...@yahoo.com writes: Doaitse Swierstra wrote: One of this differences between Haskell and Clean I did not see mentioned in this discussion is that Clean does not allow so-called partial parametrisation. I.e. all function calls have to be fully saturated I don't understand what you mean. Can you give an example ? I think the idea was that Clean doesn't support a syntax like map (**2) This terminology is new to me, I would normally call that partial application. Googling partial parametrization gives me some papers¹ that appear to use this term as a synonym. I'm surprised that (if) Clean doesn't support it. -k ¹ http://cat.inist.fr/?aModele=afficheNcpsidt=5420616 and http://www.springerlink.com/content/wg64116566522061/ -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: What's the deal with Clean?
Why speak nonsense when you can test it? // module nonsense import StdEnv nonsense = map ((^) 2) Start = nonsense [1,2,3] // Running gives: [2,4,8] Best wishes Stephen 2009/11/8 L Spice jadenb1...@yahoo.com: John van Groningen johnvg at cs.ru.nl writes: Doaitse Swierstra wrote: One of this differences between Haskell and Clean I did not see mentioned in this discussion is that Clean does not allow so-called partial parametrisation. I.e. all function calls have to be fully saturated I don't understand what you mean. Can you give an example ? Kind regards, John van Groningen I think the idea was that Clean doesn't support a syntax like map (**2) for a function that will take a list and square its elements. The call to map there is not fully saturated, since it's waiting for another argument. (As a disclaimer, I've not used Clean, so I could be speaking nonsense; it's just how I read the original statement.) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: What's the deal with Clean?
My impression is the saturated-ness that Doaitse speaks of is covered in Urban Boquist's phd thesis on the GRIN intermediate language - circa page 31. http://www.cs.chalmers.se/~boquist/phd/ As per the code snippet above Clean handles partial application entirely adequately. Best wishes Stephen Doaitse Swierstra wrote: One of this differences between Haskell and Clean I did not see mentioned in this discussion is that Clean does not allow so-called partial parametrisation. I.e. all function calls have to be fully saturated ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: What's the deal with Clean?
One of this differences between Haskell and Clean I did not see mentioned in this discussion is that Clean does not allow so-called partial parametrisation. I.e. all function calls have to be fully saturated I think there may be a misunderstanding here. Beware: I haven't used Clean in a while. (1) Clean didn't have sections. This is no big deal. Clean does have flip in StdFunc. (x +) = (+) x (+ y) = (flip (+)) y (2) Clean requires saturated *DEFINITIONS*. If you declare f :: A B C - D then each rule you give for f must have exactly three arguments. If you declare f :: A - B - C - D then each rule you give for f must have exactly one argument. See section 3.7 of the Clean 2.1 language report. This has no consequences for how you can *apply* such a function. Section 3.7.1 of the report is explicit: In CLEAN all symbols (functions and constructors) are defined with fixed arity. However, in an application it is of course allowed to apply them to an arbitrary number of arguments. A curried application of a function is an application of a function with a number of arguments which is less than its arity (note that in CLEAN the arity of a function can be derived from its type). With the aid of the predefined internal function _AP a curried function applied on the required number of arguments is transformed into an equivalent uncurried function application. The type axiom's (sic.) of the CLEAN type system include for all s defined with arity n the equivalence of s::(t1-(t2-(...(tn-tr)...)) with s::t1 t2 ... tn - tr. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: What's the deal with Clean?
John van Groningen johnvg at cs.ru.nl writes: Doaitse Swierstra wrote: One of this differences between Haskell and Clean I did not see mentioned in this discussion is that Clean does not allow so-called partial parametrisation. I.e. all function calls have to be fully saturated I don't understand what you mean. Can you give an example ? Kind regards, John van Groningen I think the idea was that Clean doesn't support a syntax like map (**2) for a function that will take a list and square its elements. The call to map there is not fully saturated, since it's waiting for another argument. (As a disclaimer, I've not used Clean, so I could be speaking nonsense; it's just how I read the original statement.) ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
