[Haskell-cafe] TryHaskell in the classroom!

2010-09-03 Thread Fritz Ruehr
ratifying to have my abstract proposition about the character of the community backed up by a concrete existential witness, live in the classroom :) . Thanks again to Chris, Gwern Branwen, _why (of TryRuby) and everyone else for their efforts and inte

[Haskell-cafe] How do we decide on the new logo?

2009-01-02 Thread Fritz Ruehr
g success at all costs). In the past, these funds have been used to purchase courtesy shirts for a few Haskell luminaries, at the discretion of the store proprietor. (Currently I think there are about $60 available.) -- Fritz (Ruehr) ___ Ha

[Haskell-cafe] New Haskell logo contest

2008-12-23 Thread Fritz Ruehr
of the Haskell merchandise page on CafePress! :) -- Fritz Ruehr ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe

Re: [Haskell-cafe] Bug in Hugs, Haskell behavior question

2008-04-04 Thread Fritz Ruehr
least. -- Fritz On Fri 4 Apr 08, at 6:49 pm, Derek Elkins wrote: Top-level bindings are irrefutable, so 2 = 3 is fine, if vacuous. On Fri 4 Apr 08, at 6:53 pm, Ryan Ingram wrote: On 4/4/08, Fritz Ruehr <[EMAIL PROTECTED]> wrote: In fact, even this goes through without a hitch!

[Haskell-cafe] Bug in Hugs, Haskell behavior question

2008-04-04 Thread Fritz Ruehr
In lab the other day I was showing pattern bindings to a student and broached a limiting case, one with no variables to be bound in the pattern. I was surprised to find that Hugs crashed when I tried a pattern binding at top level like this: (2,[1,4],5) = (2,[1,4],5) It also crashe

Re: [Haskell-cafe] Very freaky

2007-07-11 Thread Fritz Ruehr
Once during a talk I noticed I was getting strange looks and realized I was using the term "string" too freely with an audience of non- technical people. About half of them were in a beginning linguistics class and could at least handle "trees" later on (which terminology I had thought in ad

Re: [Haskell-cafe] Just curios

2007-06-11 Thread Fritz Ruehr
For what it's worth, a handful of people who have ordered Haskell merchandise from the CafePress store over the years have had "Haskell" as a surname. I assume they look at the designs before they buy, and I can't imagine what they think of some of them, but I guess the allure of having you

Re: [Haskell-cafe] Haskell on a PDA (was "Implementing Mathematica")

2007-06-02 Thread Fritz Ruehr
I seem to recall that Aarne Ranta ran Hugs on a (Sharp) Zaurus PDA at one of the ICFPs a few years back. Aha, here in fact is a picture of his GF (Grammatical Framework), written in Haskell, running on a Zaurus: There seem to be

[Haskell-cafe] Visibility of definitions in Hugs Prelude

2007-03-18 Thread Fritz Ruehr
I am wondering about the visibility of definitions in the Hugs Prelude. More specifically, when I ask for info about the Eq class, I see a lot of instances, including: instance Eq Key On the other hand, Key is not in scope: Hugs> :info Key Unknown reference `Key' I imagine this has to

[Haskell-cafe] System.Random StdGen read fails on some strings?

2007-03-12 Thread Fritz Ruehr
According to the documentation for System.Random (see haskell.org/ghc/docs/latest/html/libraries/base/System-Random.html>): In addition, read may be used to map an arbitrary string (not necessarily one produced by show) onto a value of type StdGen. In general, the read instance of StdGen has

Re: [Haskell-cafe] Is Excel the most used -- and fucntional -- programming lanuage on Earth?

2007-01-31 Thread Fritz Ruehr
I think Pivotal () has the "live update" behavior of spreadsheets. I haven't played with it yet, but I saw Keith Hanna show off his earlier Vital system; it even updates "backwards" in some sense; see the "Direct manipulation" section at his site

[Haskell-cafe] Black Haskell Hacker's t-shirt (was Re: there's a monster in my Haskell!

2006-11-01 Thread Fritz Ruehr
I suppose this might be a good time to announce the tentative availability of BLACK t-shirts in the "Haskell Hackers" design, which in fact features a "monster". (Note that I am only responsible for the composition of elements on the shirt: the monster drawing itself comes from a dingbat font.)The

Re: [Haskell-cafe] Why does Haskell have the if-then-else syntax?

2006-07-26 Thread Fritz Ruehr
On Jul 26, 2006, at 6:44 PM, Sebastian Sylvan wrote: For example ... if :: Bool -> a -> a -> a if True t _ = t if False _ e = e -- example usage myAbs x = if (x < 0) (negate x) x I suppose there might also be a case for flipping the arguments about like this: if :: a -> a -> Bool -> a

Re: [Haskell-cafe] Defining show for a function type.

2006-07-11 Thread Fritz Ruehr
On Jul 11, 2006, at 8:27 AM, ihope wrote: On 7/10/06, Fritz Ruehr <[EMAIL PROTECTED]> wrote: Were you interested in "seeing" the function, you could do so, at least for finite, total functions (you can also enumerate them, compare them for equality, etc.). See my haskell

Re: [Haskell-cafe] Defining show for a function type.

2006-07-10 Thread Fritz Ruehr
On Jul 10, 2006, at 8:44 AM, Johan Grönqvist wrote: "deriving Show" is impossible as Func is not instance of Show. Can I make it instance of Show? I just want to define something like ... and I am not interested in actually displaying any information about the function, ... Were you interested in

Re: [Haskell-cafe] how to write an haskell binding

2006-06-28 Thread Fritz Ruehr
On Jun 27, 2006, at 10:35 AM, Brian Hulley wrote: I suppose they are the exception that proves the rule... :-) Seems like there's a real opportunity here for someone who works in the area of inference systems for error handling ... . (Hmmm, pun-potential may not be the best way to pick a re

Re: [Haskell-cafe] Re: [Haskell] (.) . (.)

2006-05-29 Thread Fritz Ruehr
odling on the back of a napkin while he chats on the phone with his other hand. My mistake. :) -- >From the thread (quoting Tom Pledger quoting me): Tom Pledger wrote: K. Fritz Ruehr writes: : | But Jerzy Karczmarczuk enlightened me as to the full generality possible | along these l

Re: [Haskell-cafe] "show" for functional types

2006-04-03 Thread Fritz Ruehr
num (a -> b) where ... instance (Enum a, Bounded a, Eq b) => Eq (a->b) where ... instance (Enum a, Bounded a, Enum b, Bounded b, Eq b) => Ord (a -> b) where ... instance (Enum a, Bounded a, Show a, Show b) => Show (a->b) where ... instance (Bounded a, Bounded b) => Bounded

Re: [Haskell-cafe] "show" for functional types

2006-04-01 Thread Fritz Ruehr
On Mar 31, 2006, at 11:43 PM, Henning Thielemann wrote: A function is a set of assignments from arguments to function values. That is, a natural way to show a function would be to print all assigments. Say Prelude> toLower [('A','a'), ('a','a'), ('1', '1'), ... In principle this instance of

[Haskell-cafe] Define combination of type classes?

2006-03-23 Thread Fritz Ruehr
What is the easiest way to name a combination of type classes, i.e., to abbreviate the fact that a certain type is an instance of several classes simultaneously? I have a vague sense that this is do-able, but that I am messing up by trying to use an empty class body as below. So in the code be

[Haskell-cafe] Alternative lambda syntax (not entirely serious)

2005-02-18 Thread Fritz Ruehr
I was introducing a fresh set of students to lambda abstraction in Haskell yesterday and had the following inspiration about a possible alternative syntax. I didn't end up showing the idea to the students -- too confusing -- but I thought I would float it here, as long as nobody takes it too seriou

Re: [Haskell-cafe] Point-free style

2005-02-14 Thread Fritz Ruehr
On Feb 14, 2005, at 2:07 AM, Daniel Fischer wrote: A question for the point-free society: Is there any advantage of defining (.<) = (.) . (.) rather than f .< g = \x y -> f (g x y) -- or f $ g x y ? Analogous question for (.) . (.) . (.) etc. Well, from the fact that you even pose the question

Re: [Haskell-cafe] Point-free style

2005-02-11 Thread Fritz Ruehr
Hmm, Hugs gives me this: (.) . (.) . (.) :: (a -> b) -> (c -> d -> e -> a) -> c -> d -> e -> b which I think is correct, if still not transparent in its meaning. (ghci gives me a slightly re-named and explicitly quantified variation). Basically, the idea is that this sort of expression,

Re: [Haskell-cafe] Re: Point-free style

2005-02-10 Thread Fritz Ruehr
Jerzy pointed out the utility (well, at least the *possibility*) of expressions such as the following when writing points-free code (or perhaps per Matthew it should be "pointy code" :) ): (.) . (.) . (.) This is the function which composes a 1-argument function with a 3-argument functi

Re: [Haskell-cafe] mathematical notation and functional programming

2005-01-28 Thread Fritz Ruehr
Well, I don't know about modern works which might appeal to knowledge of FP languages, but there is a well-known, 2-volume work by Cajori: Cajori, F., A History of Mathematical Notations, The Open Court Publishing Company, Chicago, 1929 (Available from Dover). I know it through Ken Iverson

Re: [Haskell-cafe] Hugs for Zaurus

2005-01-22 Thread Fritz Ruehr
Hi John, I'm curious if you know what the requirements (memory, model, etc.) for running Hugs on a Zaurus might be: I am not normally a PDA sort of person, but a quick search indicates that Zauruses (Zauri?) are available (used) for around US $30-50 (e.g., 2MB ZR 5800 through 64 MB SL-5500). I'

Re: [Haskell-cafe] Haskore Wiki (really Haskore T-shirt)

2004-11-29 Thread Fritz Ruehr
emed Merchandise, Inc. make no profit on the merchandise we sell at cost through CafePress. -- Fritz Ruehr PS: There are also some Haskell-themed infant/toddler clothing items that haven't made it onto the Haskell merchandise page yet, see <http://www.cafepress.com/HaskellBoys> and

Re: [Haskell-cafe] Combination-lock problem

2004-08-12 Thread Fritz Ruehr
Well, as far as that goes, we can shave off a little bit (around 7%) this way: combs = mapM (\k->[0..k]) (As a bonus, it's even a bit more cryptic/symbolic, in the fine tradition of APL one-liner character-shavings.) But who's counting? :) :) :) -- Fritz Ruehr On Aug 11, 200

Re: "listProduct" -- is this a standard function?

2003-10-16 Thread K. Fritz Ruehr
I don't know of a type-based search tool for Haskell libraries, but I vaguely recall someone pursuing this idea using type isomorphisms to provide more robust results. This actually came up at lunch the other day*, where someone pointed out that you'd want to allow not only for type isomorphisms (e

New Haskell and FPO merchandise available

2003-08-18 Thread K. Fritz Ruehr
p soon). Certainly if there are any logos from the original set you would like turned into a product, or any other variations, let me know by return mail (see <http://www.willamette.edu/~fruehr/logos/intro.html>). -- Fritz Ruehr PS: Thanks to all who made such encouraging comment

Re: Learning Haskell and FP

2001-01-16 Thread Fritz Ruehr
essence, indexing into an array of statements, but the syntax is rather cumbersome." This is in reference to historical variations on switch-like statements (and consistent with a running theme, typical in PL texts, about the extremes of orthogonality found in Algol 68). -- Fritz