[Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
Claus Reinke wrote: - oscon seems to be a huge event. A bold idea would be to redo a talk of another speaker in Haskell and accidentally surpass the techniques presented there :) Alas, this doesn't work for OSCON since there are too many talks attendees have to choose between and the event starts with the tutorials, so the audience doesn't know a common talk it could compare the Haskell tutorial to. Regards, apfelmus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
On 21/04/07, apfelmus [EMAIL PROTECTED] wrote: Dan Weston wrote: -- Why is this not in Prelude? dup x = (x,x) It is (almost). It's called join (,) It's unfortunate that the Monad instance for ((-) e) isn't in the Prelude. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
Dan Weston wrote: -- Why is this not in Prelude? dup x = (x,x) It is (almost). It's called join (,) Regards, apfelmus ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
I think you are right. If you used something like a theorem prover as an example, you accidentally send the messsage that Haskell is very useful for esoteric stuff that only academics are interested in. Now, that doesn't mean that the example has to solve a real problem, but it does need to be something that the audience can relate to their own problems. There's already a lot of general buzz about functional techniques. Closures and lambda expressions are being, or have been, added to several imperative languages. This naturally leads to interest in higher order functions. The concurrency revolution is driving interest in immutable values and lockless algorithms. For people who do transactional work, having launchTheMissiles in the middle of a transaction be caught by the type system is incredible. At least some of the interest in dynamic types is driven by frustration with dealing with type annotations. So really, the example code just has to solve a problem they recognize. Even the sudoko solvers would be good, trite as they are. Or, some of the unix tools in Haskell. $0.02 -SMD On 4/19/07, Lennart Augustsson [EMAIL PROTECTED] wrote: A theorem prover might be a really cool example, but if there's one person in the audience that cares then Simon is lucky. :) You need to have examples that people can recognize and see the utility of. -- Lennart On Apr 19, 2007, at 20:48 , DavidA wrote: Simon Peyton-Jones simonpj at microsoft.com writes: But, just to remind you all: I'm particularly interested in concrete examples (pref running code) of programs that are * small * useful * demonstrate Haskell's power * preferably something that might be a bit tricky in another language I have something that I think nearly fits the bill. Unfortunately, I don't think it quite works because it's a bit specialised. However, I think it suggests a possible area to look, which I'll mention at the end. It's a theorem prover for intuitionistic propositional logic: http://www.polyomino.f2s.com/david/haskell/gentzen.html It's much shorter in Haskell than it would be in other languages. (It's even shorter than the ML that I based it on, because of some shortcuts I can take using lazy evaluation.) Strengths of Haskell that it demonstrates are: * How easy it is to define datatypes (eg trees), and manipulate them using pattern matching, with constructors, Eq, Show coming for free. * How lazy evaluation reduces code length by letting you write code that looks like it would do too much, and then lazy evaluate it (in the proof function) * The ability to extend the syntax with new symbolic operators * Use of higher order functions to simplify code (the (+++) operator) The problem is that I think Gentzen systems are a bit obscure. But I think you could probably show most of the same strengths of Haskell in something similar: game search, eg alpha-beta algorithm. Another advantage of doing game search would be that you'd get to show off persistent data structures (so that when you make a move in lookahead, you don't need to make a copy of the game state, because when you update the game state the old state still persists). ___ 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 ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
Derek Elkins wrote: Game search is exactly an example use in Why Functional Programming Matters (http://www.math.chalmers.se/~rjmh/Papers/whyfp.html). That paper, 23 years later, is still pretty compelling. Perhaps, it should just be modernized and somewhat expanded. I'll echo Lennart's response to the theorem proving suggestion :-) Tom Moertel's parallel port scanner is much more the kind of thing that will get people's attention. It's practical; it's parallel; and it's short. And for Simon's convenience, it's already been written, so he can concentrate on presenting it, rather than writing it. b ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
Simon Peyton-Jones simonpj at microsoft.com writes: But, just to remind you all: I'm particularly interested in concrete examples (pref running code) of programs that are * small * useful * demonstrate Haskell's power * preferably something that might be a bit tricky in another language I have something that I think nearly fits the bill. Unfortunately, I don't think it quite works because it's a bit specialised. However, I think it suggests a possible area to look, which I'll mention at the end. It's a theorem prover for intuitionistic propositional logic: http://www.polyomino.f2s.com/david/haskell/gentzen.html It's much shorter in Haskell than it would be in other languages. (It's even shorter than the ML that I based it on, because of some shortcuts I can take using lazy evaluation.) Strengths of Haskell that it demonstrates are: * How easy it is to define datatypes (eg trees), and manipulate them using pattern matching, with constructors, Eq, Show coming for free. * How lazy evaluation reduces code length by letting you write code that looks like it would do too much, and then lazy evaluate it (in the proof function) * The ability to extend the syntax with new symbolic operators * Use of higher order functions to simplify code (the (+++) operator) The problem is that I think Gentzen systems are a bit obscure. But I think you could probably show most of the same strengths of Haskell in something similar: game search, eg alpha-beta algorithm. Another advantage of doing game search would be that you'd get to show off persistent data structures (so that when you make a move in lookahead, you don't need to make a copy of the game state, because when you update the game state the old state still persists). ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: How Albus Dumbledore would sell Haskell
A theorem prover might be a really cool example, but if there's one person in the audience that cares then Simon is lucky. :) You need to have examples that people can recognize and see the utility of. -- Lennart On Apr 19, 2007, at 20:48 , DavidA wrote: Simon Peyton-Jones simonpj at microsoft.com writes: But, just to remind you all: I'm particularly interested in concrete examples (pref running code) of programs that are * small * useful * demonstrate Haskell's power * preferably something that might be a bit tricky in another language I have something that I think nearly fits the bill. Unfortunately, I don't think it quite works because it's a bit specialised. However, I think it suggests a possible area to look, which I'll mention at the end. It's a theorem prover for intuitionistic propositional logic: http://www.polyomino.f2s.com/david/haskell/gentzen.html It's much shorter in Haskell than it would be in other languages. (It's even shorter than the ML that I based it on, because of some shortcuts I can take using lazy evaluation.) Strengths of Haskell that it demonstrates are: * How easy it is to define datatypes (eg trees), and manipulate them using pattern matching, with constructors, Eq, Show coming for free. * How lazy evaluation reduces code length by letting you write code that looks like it would do too much, and then lazy evaluate it (in the proof function) * The ability to extend the syntax with new symbolic operators * Use of higher order functions to simplify code (the (+++) operator) The problem is that I think Gentzen systems are a bit obscure. But I think you could probably show most of the same strengths of Haskell in something similar: game search, eg alpha-beta algorithm. Another advantage of doing game search would be that you'd get to show off persistent data structures (so that when you make a move in lookahead, you don't need to make a copy of the game state, because when you update the game state the old state still persists). ___ 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: How Albus Dumbledore would sell Haskell
DavidA wrote: Simon Peyton-Jones simonpj at microsoft.com writes: But, just to remind you all: I'm particularly interested in concrete examples (pref running code) of programs that are * small * useful * demonstrate Haskell's power * preferably something that might be a bit tricky in another language I have something that I think nearly fits the bill. Unfortunately, I don't think it quite works because it's a bit specialised. However, I think it suggests a possible area to look, which I'll mention at the end. It's a theorem prover for intuitionistic propositional logic: http://www.polyomino.f2s.com/david/haskell/gentzen.html It's much shorter in Haskell than it would be in other languages. (It's even shorter than the ML that I based it on, because of some shortcuts I can take using lazy evaluation.) Strengths of Haskell that it demonstrates are: * How easy it is to define datatypes (eg trees), and manipulate them using pattern matching, with constructors, Eq, Show coming for free. * How lazy evaluation reduces code length by letting you write code that looks like it would do too much, and then lazy evaluate it (in the proof function) * The ability to extend the syntax with new symbolic operators * Use of higher order functions to simplify code (the (+++) operator) The problem is that I think Gentzen systems are a bit obscure. But I think you could probably show most of the same strengths of Haskell in something similar: game search, eg alpha-beta algorithm. Another advantage of doing game search would be that you'd get to show off persistent data structures (so that when you make a move in lookahead, you don't need to make a copy of the game state, because when you update the game state the old state still persists). Game search is exactly an example use in Why Functional Programming Matters (http://www.math.chalmers.se/~rjmh/Papers/whyfp.html). That paper, 23 years later, is still pretty compelling. Perhaps, it should just be modernized and somewhat expanded. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
