Re: Learning Haskell and FP
On Fri, 5 Jan 2001 10:26:19 -0500 (EST) Patrick M Doane [EMAIL PROTECTED] wrote: [snip] I think a really good beginner's tutorial on I/O could be started from this paper: - Start immediately with using the 'do expression' and don't worry about the history that led to its development. Actually, the history, especially from a comparative programming languages standpoint, can sometimes be useful for motivation. For example, many Java textbooks motivated study of the language by explaining the need for a C-style language without explicit memory allocation or explicit pointer casting. Similarly, an on-line document for C# motivated it by explaining the history of how it grew out of a need for a language similar to C and C++ (the document somehow left out the Java comparison :-( ), but that allowed programmers to develop more efficiently in it. Even for a "Haskell in a Nutshell"-style textbook, a couple of paragraphs comparing Haskell to other languages from a historical viewpoint and describing the advantages and disadvantages of Haskell in particular could prove quite useful. [snip] Many people are also annoyed by an author using new vocabulary even if it is well defined. It's better to get them comfortable with the system first. That depends on which new vocabulary is being mentioned, though. That may true for unnecessary new vocabulary, such as "monads" for the first chapter. However, e.g. in the following example (borrowed from Chapter 3 of _A Gentle Introduction to Haskell, Version 98,_ by Paul Hudak): add :: Integer - Integer - Integer add x y = x + y it is hard not to introduce such vocabulary as "has type," "arrow" (or "mapping"), and maybe even "currying." [snip] - Conclude with explaining the difference between executing an action and building a value to execute the action. There is no need to point out that this is a requirement of being a lazy language. Instead point out the benefits such a system provides to back up the claim that Haskell truly is "the world's finest imperative programming language." Forgive me if I am ignorant, but who claimed that Haskell was an "imperative" language? Also, in order to take full advantage of Haskell, it would seem necessary to get used to functional programming style (the Haskell school of expression, in particular). It seems that using Haskell as an "imperative" language is a bit like thinking in C when programming in C++; only worse, since the imperative habits are being brought into the functional, rather than the OO, realm. --Ben -- Benjamin L. Russell [EMAIL PROTECTED] [EMAIL PROTECTED] "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Learning Haskell and FP
Erik Meijer wrote: Nope, I also think that Haskell is the world's finest *imperative* language (and the world's best functional language as well). The beauty of monads is that you can encapsulate imperative actions as first class values, ie they have the same status as functions, lists, ... Not many other imperative languages have statements as first class citizens. It may be the only imperative language that doesn't have mutable variables as a standard part of the language. :-) I do agree that Haskell has a lot of nice imperative features, but it is also missing a few that are fundamental to imperative programming. Personally, I'd love to see a language that is imperative from the ground up, that has some of the design features of Haskell (especially the type system), but I don't think that Haskell is that language (yet?). A question for the list: Is there a book that gives a good introduction to Hindley-Milner typing theory and practice, and that delves into its various extensions (e.g. imperative programs, type classes, record types). I have Mitchell's book out from the library, but it seems a bit limited with respect to extentions (I think it deals with subtypes, but not type classes and mutable variables, for example). Cheers, Theodore Norvell Dr. Theodore Norvell[EMAIL PROTECTED] Electrical and Computer Engineering http://www.engr.mun.ca/~theo Engineering and Applied SciencePhone: (709) 737-8962 Memorial University of Newfoundland Fax: (709) 737-4042 St. John's, NF, Canada, A1B 3X5 ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: Learning Haskell and FP
On Wed, 3 Jan 2001, Simon Peyton-Jones wrote: I'm sure that's right. Trouble is, we're the last people qualified to write one! Here's a suggestion: would someone like to write such a guide, from the point of view of a beginner, leaving blanks that we can fill in, when you come across a task or issue you don't know the answer to? That is, you provide the skeleton, and we fill in the blanks. I read your paper on taming the Awkward Squad several months ago as my first exposure to Haskell. I think it is an excellent paper and really convinced me that Haskell was worthwhile to learn and use. There are aspects to the paper that are like a tutorial, but I think it would be overwhelming for a programmer not used to reading papers from academia. I think a really good beginner's tutorial on I/O could be started from this paper: - Start immediately with using the 'do expression' and don't worry about the history that led to its development. - Avoid mentioning 'monad' and other mathematical terms until much latter in the game. It is better to see the system in action and then find out it has a nice solid foundation. Many people are also annoyed by an author using new vocabulary even if it is well defined. It's better to get them comfortable with the system first. - Take advantage of the 2d syntax rules to avoid the unneeded braces and semicolons. Syntax with little punctuation seems to go a long way with many programmers. Pointing out the similarities to Python here could be appropriate. - After working through several examples, show that the 'do expression' is short hand for some more basic primitive operators. These can be more appropriate to use in some circumstances. - Conclude with explaining the difference between executing an action and building a value to execute the action. There is no need to point out that this is a requirement of being a lazy language. Instead point out the benefits such a system provides to back up the claim that Haskell truly is "the world's finest imperative programming language." Some points would still be difficult to get through: - Explaining the type system. There is no avoiding this, and users will have to learn it. - Working through the difference between 'unit' and 'void'. Perhaps this can be avoided in a beginning tutorial. A possible confusing example in the paper is that of composing putChar twice while throwing away the result. People used to C or Java might immediately think "but it doesn't have a result to through away!" - Some amount of understanding for Haskell expressions is going to be needed to understand examples. An I/O centric tutorial would want to explain as things go along as needed. I would avoid other parts of the paper for a first attempt at some new tutorial material. Any thoughts? I could take a first stab at this if people think it would be a useful direction. Patrick ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Learning Haskell and FP
On Wed, 3 Jan 2001, Michael Zawrotny wrote: 1. How the #$!? do I read some data from a file. Good, I've got the data, now I can work on it. Nope, now I have an "IO thingie" whatever that is, but all of the standard functions want a regular "thingie" now what? I do not know if you actually wanted an answer to this, but I'm sick of hearing this FAQ everywhere when the answer is so simple. There are exactly two ways to do this (one of them is actually syntactic sugar for the other). 1. Use the do notation: do regularThingie - IOThingie return (doWhateverYouWantWith regularThingie) 2. Use bind ( = ): IOThingie = \regularThingie - return (doWhateverYouWantWith regularThingie) Note: Both constructs produces IO thingies. This is the real beauty of it, if you have a value that is dependent on the environment (i.e. a IO value) you can use it as a regular value inside one of the above constructs, but the result will always be an IO value (The result will depend on the environment because it uses a value dependent of the environment). This is no problem, just accept it. Can everyone include an answer to this FAQ everywhere, phleaze! /Lars L ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
I do not know if you actually wanted an answer to this, but I'm sick of hearing this FAQ everywhere when the answer is so simple. There are exactly two ways to do this (one of them is actually syntactic sugar for the other). [..] Can everyone include an answer to this FAQ everywhere, phleaze! /Lars L Thanks Lars... I've added it to the Wiki. HINT TO EVERYONE: *Anyone* can add this kind of thing to the Wiki. Just find the appropriate page and click the EditText link at the bottom. To create a new page just name it (in BiCapitalised form), and the name becomes a hyperlink. Click on the link, then EditText on the new page and you're done. The Haskell Wiki is at: http://haskell.org/wiki/wiki I *do not* maintain it, I just evangelise for it. :-) --KW 8-) ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
| 1. How the #$!? do I read some data from a file. Good, I've | got the data, now I can work on it. Nope, now I have an "IO | thingie" whatever that is, but all of the standard functions want | a regular "thingie" now what? Perhaps this would be a good moment to advertise the revised version of Tackling the Tackling the Awkward Squad: monadic input/output, concurrency, exceptions, and foreign-language calls in Haskell http://research.microsoft.com/~simonpj/#marktoberdorf (Concerning the thread I'm responding to, it gives an introduction to monadic input/output.) I've revised and extended this tutorial quite a bit since I announced it last year, with a lot of help from people on the Haskell mailing list: thank you! Further suggestions are most welcome. Simon Abstract Functional programming may be beautiful, but to write real applications we must grapple with awkward real-world issues: input/output, robustness, concurrency, and interfacing to programs written in other languages. These lecture notes give an overview of the techniques that have been developed by the Haskell community to address these problems. I introduce various proposed extensions to Haskell along the way, and I offer an operational semantics that explains what these extensions mean. ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
Perhaps this would be a good moment to advertise the revised version of Tackling the Tackling the Awkward Squad: monadic input/output, concurrency, exceptions, and foreign-language calls in Haskell http://research.microsoft.com/~simonpj/#marktoberdorf (Concerning the thread I'm responding to, it gives an introduction to monadic input/output.) Many thanks ! This is just what I need. Will read it before bed tonight... ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
One more thing: I'm happy to incorporate any tutorial material into haskell.org. If you have material that would be appropriate please let me know and I'll add it to the site. I know there are some very good slides from Haskell courses that could be put into haskell.org. For what it's worth, I'm happy to contribute my solutions to the exercises in "Haskell: Craft" for posting on haskell.org. However, I assume that in at least one place, the book is used for coursework and would, hence, such posting would be discouraged. Hi Paul. Hi Benjamin. Cheers, Doug ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On Wed, 3 Jan 2001 22:55:17 -0800 (PST) Fritz K Ruehr [EMAIL PROTECTED] wrote: [snip] An O'Reilly "nutshell" book is an even better suggestion than my "Design Patterns in Haskell" of a few days back, at least from the perspective of marketing and promotion. But it raises the issue of an appropriate animal mascot for the cover; I can only come up with the Uakari, an exotic-looking rainforest monkey, which sounds similar to "Curry". (look here for a picture:) http://www.animalsoftherainforest.com/uakari.htm Lalit Pant ( [EMAIL PROTECTED] ) (alternatively, [EMAIL PROTECTED] ) wrote an article in the May 2000 issue of _Java Report_ entitled "Developing Intelligent Systems With Java and Prolog" that described a Prolog implementation of the A-star search algorithm. Lalit stated that Prolog was useful for algorithm prototyping. Perhaps Lalit Pant and Simon Peyton Jones could collaborate together on an article, perhaps overseen by Paul Hudak, on prototyping search algorithms in Haskell, also for _The Java Report?_ If this article then had a high readership, maybe the article's success could then justify publication of an O'Reilly _Haskell in a Nutshell_ book? --Ben P. S. (Hi Doug Fields. I didn't know that you were reading this mailing list. I guess that I should also greet Professor Paul Hudak: Hello, Professor Hudak. Sorry about Collectively Speaking. How's jazz in general?) Benjamin L. Russell [EMAIL PROTECTED] [EMAIL PROTECTED] "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
"Karl M. Syring" [EMAIL PROTECTED] writes: Mind if I "me too" a bit? I had just read the SICP, and I too found that the Gentle Introduction served well as an introduction to the Haskell syntax. If you start out with zero knowledge in functional programming, as I do, the GITH is really not very helpful. Exactly. It's "gentle" if you know functional programming, but probably not otherwise. PS: are the members of the list expecting to get replies by private mail? Expecting? I'd have no qualms about replying to people privately, but then perhaps I am the obnoxious kind of person. :-) Negative feedback is scarce (although this thread might favorably diverge to -cafe? Followup-To: set). -kzm -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
| PS: are the members of the list expecting to get replies by | private mail? The thing to do is to switch the thread to [EMAIL PROTECTED] haskell@haskell-org is meant for openers; longer threads should move to haskell-cafe. That way people can control how inundated they get. You can "move" by simply adding "-cafe" into the address when you reply. Simon ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On Tue, 2 Jan 2001, Paul Hudak wrote: Unforunately, the "Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. John and I should probably rename this document, since it really isn't a very gentle intro at all. We should probably also downplay it's prominance on the haskell website. It was written rather quickly many years ago, at a time when there was not a single textbook on Haskell. So it's probably outlived it's purpose, although I do believe that some people still find it useful. I learned Haskell from it. Later, people corrected my style and I learned some more. Of course, I did not do any serious Haskell programming yet, except for my infamous primes finding algorithms. Regards, Shlomi Fish -Paul ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell -- Shlomi Fish[EMAIL PROTECTED] Home Page: http://t2.technion.ac.il/~shlomif/ Home E-mail: [EMAIL PROTECTED] The prefix "God Said" has the extraordinary logical property of converting any statement that follows it into a true one. ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
Thanks to everyone for their comments regarding "GITH". I conclude that: -- it is useful to people who have previously programmed in Scheme or some other functional language -- it is a difficult read for those not familiar with FP concepts, and certainly not appropriate for novice programmers -- given the dearth of free documentation on Haskell, it serves a useful purpose -- the title is misleading Also thanks to George Russell for reminding me that the intro states clearly that: Our goal is to provide a gentle introduction to Haskell for someone who has experience with at least one other language, preferably a functional language (even if only an "almost-functional" language such as ML or Scheme). So I suppose the main thing that John and I should think about is changing the title. Something like "An Introduction to Haskell for People Who Have Previously Programmed in Scheme or Some Other Functional Language" might be good! :-) Of course changing the title might confuse people to whom the document was recommended. It may be that a clarifying remark on haskell.org is warranted. Anyway, thanks again for the comments. Best to All for the New Year, -Paul ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
One more thing: I'm happy to incorporate any tutorial material into haskell.org. If you have material that would be appropriate please let me know and I'll add it to the site. I know there are some very good slides from Haskell courses that could be put into haskell.org. The document sources to the Gentle Intro are also available. We've already had some very generous help with it and Paul and I will be happy to support anyone that would like to improve it further. Finally, another thing that would be really nice in the way of tutorials is one from the perspective of an experienced C++ / Java programmer. Even a relatively short work that maps between the O-O terminology and the Haskell world would be quite useful. John ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
Paul Hudak wrote: [snip] So I suppose the main thing that John and I should think about is changing the title. Something like "An Introduction to Haskell for People Who Have Previously Programmed in Scheme or Some Other Functional Language" might be good! :-) "A Gentle Introduction to Haskell for Functional Programmers" might be better. Then hopefully people who have been directed to "A Gentle Introduction" will not be confused. ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
Paul Hudak [EMAIL PROTECTED] wrote: Thanks to everyone for their comments regarding "GITH". I conclude that: -- it is useful to people who have previously programmed in Scheme or some other functional language -- it is a difficult read for those not familiar with FP concepts, and certainly not appropriate for novice programmers -- given the dearth of free documentation on Haskell, it serves a useful purpose -- the title is misleading Also thanks to George Russell for reminding me that the intro states clearly that: Our goal is to provide a gentle introduction to Haskell for someone who has experience with at least one other language, preferably a functional language (even if only an "almost-functional" language such as ML or Scheme). GITH was a bit much for me. However, I have a slightly different take on the reason why. My original background (undergrad and PhD) is in biochemistry. Most of my programming, etc. is self-taught, although I got through about third year's worth of course work for an undergrad CS degree while I was at my previous job. In the course of teaching myself various things, I dabbled in both scheme and common lisp and more recently in SML and OCaml (and obviously Haskell as well). The reason that I found GITH difficult wasn't that the concept of programming with functions/functional style was new to me. What got me was that the concepts and notations were much more "mathematical" than "programmatic". In my explorations of various languages, my experience with introductions to scheme/CL has mostly been that they tend to show how to do things that are familiar to imperative programmers, plus all of the things that you can do with functions as first class values. With intros to SML, OCaml and Haskell, there is a much greater emphasis on types, type systems, and provable program correctness. The main difference being the emphasis on doing familiar things in a better way followed by some new things (scheme/lisp intros) versus throwing you into what may be completely uncharted territory (formal type systems, monads, functors) in SML/OCaml/Haskell intros. There also seems to be the tendency to assume that the meaning of a type signature like map :: (a-b) - [a] - [b] is inherently obvious. To someone unfamiliar with HM type systems and whose last course in mathematics was more than a decade ago, it might as well be greek. The thing that I would most like to see would entitled "A Practical Guide to Haskell" or something of that nature. After working through some of the online tutorials and a fair portion of "Craft of Functional Programming", I thought, "Ok, I do most of these excercises, and am comfortable. Let's try that utility program I've been thinking about for the last couple weeks." What I ran into was scenarios like the ones listed below (some of which have since been solved): 1. How the #$!? do I read some data from a file. Good, I've got the data, now I can work on it. Nope, now I have an "IO thingie" whatever that is, but all of the standard functions want a regular "thingie" now what? 2. I need to do some XML processing. Go to haskell.org, find links to HaXML and install it. Try to use it... Nope, no documentation that is understandable to me. Ok, look at the source to the one demo program that does something close to what I want. Nope, it was written in the "It's functional and therefore self-documenting" style. (Note, this is not intended to be a shot at the implementors of HaXML. It is clear from the description of the library and the functions of the included programs that the library is complete and well thought out. I am also sure that someone already fluent in Haskell who is used to looking at type signatures to deduce the purpose of a function can do sophisticated things with it. My only criticism was that it wasn't approachable to someone who is starting to feel somewhat comfortable with Haskell and wants to "do" something useful with it, as opposed to exercises from a book or tutorial.) 3. I gave up on Haskell for that particular utility and wrote it OCaml. One is tempted to come to the conclusion that Haskell is not suited for "normal" programmers writing "normal" programs. I don't necessarily think that is true, but it is difficult for someone who is used to imperative/OO style programming and has dabbled in impure functional languages. To be fair, I had almost the same reaction to SML/OCaml when I first encountered them. Working on Haskell and reading "Craft" made it much easier to go back and look at them again. It's probably that in the spectrum of imperative functional languages, scheme/CL are farther to the left than SML/OCaml, which is still left of Haskell. In the case of someone like me coming from C, C++, perl, python, etc., the extreme right is inherently much less familiar territory than the middle ground. The tendency of the written materials to get more
Re: Learning Haskell and FP
On Wed, Jan 03, 2001 at 01:28:41AM -0800, Simon Peyton-Jones wrote: Here's a suggestion: would someone like to write such a guide, from the point of view of a beginner, leaving blanks that we can fill in, when you come across a task or issue you don't know the answer to? That is, you provide the skeleton, and we fill in the blanks. If someone should be bold enough to start writing such a guide, I would be more than happy than to try to contribute to it and also set it up as a Debian package. Cheers, Bill -- "AIX is Unix from the universe where Spock had a beard." -- Unknown ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Ketil Malde Sent: Wednesday, January 03, 2001 8:28 AM To: George Russell Cc: [EMAIL PROTECTED]; i r thomas; [EMAIL PROTECTED] Subject: Re: Learning Haskell and FP George Russell [EMAIL PROTECTED] writes: I think Paul is being unduly modest. I found it very useful when I first learnt Haskell. But I did already know ML, so maybe the Gentle Introduction would be harder going for someone who didn't know anything about functional programming. Mind if I me too a bit? I had just read the SICP, and I too found that the Gentle Introduction served well as an introduction to the Haskell syntax. I think it'd be fine if the title were a bit less ambitious - it isn't really aimed at the novice, I think. It's been a while since I read it tho' If you start out with zero knowledge in functional programming, as I do, the GITH is really not very helpful. I have found the Clean tutorial (cleanBookI.pdf) a good place to get my feet wet. Now, I gently try to move on. Regards Karl M. Syring PS: are the members of the list expecting to get replies by private mail? ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
-Original Message- From: Simon Peyton-Jones [mailto:[EMAIL PROTECTED]] Sent: Wednesday, January 03, 2001 10:02 AM To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: RE: Learning Haskell and FP | PS: are the members of the list expecting to get replies by | private mail? The thing to do is to switch the thread to [EMAIL PROTECTED] haskell@haskell-org is meant for openers; longer threads should move to haskell-cafe. That way people can control how inundated they get. You can move by simply adding -cafe into the address when you reply. I was somewhat irritated about the inclusion of the individual reply adresses. Most mailing list software seems to remove the email adresses of the senders. On the other hand, there are people that use the private mail for archiving purposes, iff the content seems to be potentially important while forwarding the letters send to the list to bit nirvana. Regards Karl M. Syring ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On Wed, 03 Jan 2001 11:26:53 -0500 Michael Zawrotny [EMAIL PROTECTED] wrote: [snip] The reason that I found GITH difficult wasn't that the concept of programming with functions/functional style was new to me. What got me was that the concepts and notations were much more "mathematical" than "programmatic". In my explorations of various languages, my experience with introductions to scheme/CL has mostly been that they tend to show how to do things that are familiar to imperative programmers, plus all of the things that you can do with functions as first class values. With intros to SML, OCaml and Haskell, there is a much greater emphasis on types, type systems, and provable program correctness. [snip] The thing that I would most like to see would entitled "A Practical Guide to Haskell" or something of that nature. [snip] One is tempted to come to the conclusion that Haskell is not suited for "normal" programmers writing "normal" programs. How would you define a "'normal' programmer writing 'normal' programs?" What exactly is a "'normal' program?" (Perhaps another way of phrasing the issue is as the "declarative" vs. "procedural" distinction, since the issue seems to be that of "what is" (types) vs. "how to" (imperative expression; i.e., procedures).) While I agree that "A Practical Guide to Haskell" would indeed be a suitable alternative for programmers from the procedural school of expression, I would caution that such an introduction would probably not be suitable for all. If I may give my own case as an example, I studied both C and Scheme (in addition to auditing a course in Haskell) in college, and favored Scheme over C precisely because of my Scheme course's emphasis on provable program correctness. This is largely a matter of background and taste: my course background was relatively focused on the design and analysis of algorithms, with provable program correctness being a related topic. Perhaps, ideally, two separate tutorials (or perhaps a single tutorial with two sections based on different viewpoints?) may be needed? The difficulty is that the conceptual distance between the declarative and procedural schools of thought seems too great to be bridged by a single viewpoint. It seems that any introduction favoring either one would risk alienating the other. Personally, I would really prefer "A Gentle Elementary Introduction to Haskell: Elements of the Haskell School of Expression with Practical Examples," but some would no doubt choose "Haskell in a Nutshell: How to Write Practical Programs in Haskell." --Ben -- Benjamin L. Russell [EMAIL PROTECTED] [EMAIL PROTECTED] "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho ___ Haskell-Cafe mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: Learning Haskell and FP
Unforunately, the "Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. John and I should probably rename this document, since it really isn't a very gentle intro at all. We should probably also downplay it's prominance on the haskell website. It was written rather quickly many years ago, at a time when there was not a single textbook on Haskell. So it's probably outlived it's purpose, although I do believe that some people still find it useful. -Paul ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
Paul Hudak wrote: Unforunately, the "Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. John and I should probably rename this document, since it really isn't a very gentle intro at all. We should probably also downplay it's prominance on the haskell website. It was written rather quickly many years ago, at a time when there was not a single textbook on Haskell. So it's probably outlived it's purpose, although I do believe that some people still find it useful. I think Paul is being unduly modest. I found it very useful when I first learnt Haskell. But I did already know ML, so maybe the "Gentle Introduction" would be harder going for someone who didn't know anything about functional programming. Nevertheless I think it might be a mistake to downplay it unless there's a better publicly-available introduction with which you can replace it. The introduction states quite clearly that Our goal is to provide a gentle introduction to Haskell for someone who has experience with at least one other language, preferably a functional language (even if only an "almost-functional" language such as ML or Scheme). and then goes on to recommend a couple of texts giving more detailed introductions to functional programming. I don't think one can ask for more. ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On Tue, 2 Jan 2001, George Russell wrote: Paul Hudak wrote: Unforunately, the "Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. John and I should probably rename this document, since it really isn't a very gentle intro at all. We should probably also downplay it's prominance on the haskell website. It was written rather quickly many years ago, at a time when there was not a single textbook on Haskell. So it's probably outlived it's purpose, although I do believe that some people still find it useful. [cut] Nevertheless I think it might be a mistake to downplay it unless there's a better publicly-available introduction with which you can replace it. Very valid observation. John, Paul: Wouldn't be worthwhile and possible to gradually upgrade it within some sort of a supervised documentation project at Yale, as part of your regular teaching curriculum? Jan ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On Tue, 2 Jan 2001, Paul Hudak wrote: Unforunately, the "Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. John and I should probably rename this document, since it really isn't a very gentle intro at all. We should probably also downplay it's prominance on the haskell website. It was written rather quickly many years ago, at a time when there was not a single textbook on Haskell. So it's probably outlived it's purpose, although I do believe that some people still find it useful. As another point of reference, I decided it was time to learn Haskell recently and this guide is what I started with. I'm familiar with Standard ML and O'Caml, and found the guide to be very easy to read and was a good starting point. I had enough information that I could read other Haskell source and understand what it was trying to do even if I didn't feel comfortable about all the details for writing programs. However, a related issue that has been causing a lot of difficulty is system installation. I'm primarily interested in building stand-alone executables where speed is an important factor, so ghc seemed the best system to work with. I've been unable to get this to work at all on a Windows system. It seems configured to use dynamic libraries but doesn't come with any in the package. I tried building from source, but it requires Happy to build (and that too needed the .dlls). On the Unix side, the installation was much smoother. I installed from source using the FreeBSD port system and everything came together without a hitch (it was a rather lengthy compile process though!). There is a definite lack of "Getting Started" material in the ghc distribution. Documentation on libraries is also rather distributed. Sometimes I need to look in the GHC manual about a library that is included with the distribution, other times I need to look in the Haskell standard library report. And if that fails, look in the Haskell standard language report for information on what is included in the Prelude. Collecting this information together would be a big benefit. I've installed Hugs on the Windows side recently, and it seemed to boot up okay. I haven't tried looking into its documentation to see if things are any different. Overall, I'm very pleased with the lannguage design and am excited about its future. Patrick ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
George Russell [EMAIL PROTECTED] writes: I think Paul is being unduly modest. I found it very useful when I first learnt Haskell. But I did already know ML, so maybe the Gentle Introduction would be harder going for someone who didn't know anything about functional programming. Mind if I me too a bit? I had just read the SICP, and I too found that the Gentle Introduction served well as an introduction to the Haskell syntax. I think it'd be fine if the title were a bit less ambitious - it isn't really aimed at the novice, I think. It's been a while since I read it tho' -kzm -- If I haven't seen further, it is by standing in the footprints of giants ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
Who are the audience for the books on Advanced Functional Programming? Academics with a theoretical CS background or someone with just a bit of understanding of FP? Ideally, I would like a course suited for someone who has completed a basic FP course. It varies a bit per school (book) and per article. But certainly LNCS 925 contains a number of chapters that should be interesting for someone with a general CS background and a basic FP course. I know it has been used in a couple of undergraduate courses on advanced functional programming. Topics, Authors, LNCS nr: - Monads, Wadler, 925 - Parser Combinators, Fokker, 925 - Constructor Classes, Jones, 925 - (Monadic) folds (or catamorphisms), Meijer Jeuring, 925 - Space leaks and heap profiling, Runciman Rojemo, 1129 - Algorithms and data structures, Okasaki, 1129 - Graph algorithms, Launchbury, 925 - User Interfaces, Carlsson Hallgren, 925, Peyton Jones Finne 1129 etc. Johan Jeuring http://www.cs.uu.nl/~johanj/ ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
Benjamin L. Russell wrote (on 28-12-00 17:35 -0500): "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho [..] Is it OK if I show off and steal some thunder? :) So much for that idea...! "(It's) An old pond! The sound of water steadily dripping in..." Actually, if I may add, the translation I remember was the following: "[It's] An old pond! The sound of water as the frog jumps in" "Kawazu" means "frog," and "tobikomu" means "(to) jump in." That makes sense. I was guessing that "kawazu" was the old form of modern "kawarazu" (`without changing'). Modern `frog' is "kaeru", though, and the transitive form of "kawaru" (`change') is also "kaeru", so I suppose there is some linguistic relationship. "tobikomu" makes much more sense this way too. I thought it was a figurative usage, but it still didn't sound right... -- Frank Atanassow, Information Computing Sciences, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-3261 Fax +31 (030) 251-379 ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On 12/28/2000 at 7:00 PM Bill Halchin wrote: Hello IR, I agree with the OU Haskell Tutorial. It is excellent!! Yes, with a bit of editing and more diagrams , it would probably be worth publishing. BTW, what is your C# source? The .NET Framework SDK is freely downloadable from MS ( around 100 megs ) and comes with a C# tutorial, C# reference and a command line C#. There are also a few chapters online of some C# books that cover issues like namespaces and attributes. I am using the Antechinus C# editor as an IDE . This comes with a few basic C# examples as well. ( for vi freaks, I have written a C# vim syntax file that will appear on vim.org once it is polished up.) ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
While it may not be advanced or mathematical enough for your needs, you may wish to read _The Haskell School of Expression: Learning Functional Programming through Multimedia,_ by Paul Hudak. This is also an introductory book on functional programming, with a special focus on Haskell, although the examples used are mainly from multimedia. Is there an online version of Hudak's book ? ( For example Bruce Eckel has online versions of all his books available online as well as in print ) "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho Translation please ! Basho is my favorite Japanese poet. Unfortunately my Japanese is at the Ohio level.. ( ohiogozaimazu) ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
Is there a good textbook on Functional Programming which starts from a base point similar to "The craft of Functional Programming" but more advanced in terms of introducing necessary topics like Category theory, catamorphisms, monads, etc? I would find such a book very useful, especially if it concentrated on lazy functional programming. You might want to have a look at the series of three books on Advanced Functional Programming, published in LNCS, as LNCS 925, 1129, and 1608. I would probably start with 925, which introduces monads, parser pretty-printing combinators, monadic catamorphisms, constructor classes, etc. -- Johan Jeuring ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
i r thomas wrote (on 28-12-00 12:50 +1000): Unforunately, the " Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. I am getting more out of Rex Paige's Two Dozen Short Lessons in Haskell. ( I am studying Haskell and C# on my own in my spare time as break from my medical practice ). What did you find unuseful about GITH? How could it be improved? What were your expectations for it? What was more useful about Rex Paige's notes? "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho Translation please ! Is it OK if I show off and steal some thunder? :) "(It's) An old pond! The sound of water steadily dripping in..." -- Frank Atanassow, Information Computing Sciences, Utrecht University Padualaan 14, PO Box 80.089, 3508 TB Utrecht, Netherlands Tel +31 (030) 253-3261 Fax +31 (030) 251-379 ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
RE: Learning Haskell and FP
Who are the audience for the books on Advanced Functional Programming? Academics with a theoretical CS background or someone with just a bit of understanding of FP? Ideally, I would like a course suited for someone who has completed a basic FP course. -Original Message- From: Johan Jeuring [mailto:[EMAIL PROTECTED]] Sent: Thursday, December 28, 2000 6:06 AM To: Doug Ransom Cc: [EMAIL PROTECTED] Subject: Re: Learning Haskell and FP Is there a good textbook on Functional Programming which starts from a base point similar to "The craft of Functional Programming" but more advanced in terms of introducing necessary topics like Category theory, catamorphisms, monads, etc? I would find such a book very useful, especially if it concentrated on lazy functional programming. You might want to have a look at the series of three books on Advanced Functional Programming, published in LNCS, as LNCS 925, 1129, and 1608. I would probably start with 925, which introduces monads, parser pretty-printing combinators, monadic catamorphisms, constructor classes, etc. -- Johan Jeuring ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
On Thu, 28 Dec 2000 16:48:57 +0100
Frank Atanassow [EMAIL PROTECTED] wrote:
i r thomas wrote (on 28-12-00 12:50 +1000):
Unforunately, the " Gentle Introduction To Haskell"
that haskell.org links to is not a very useful
introduction.
I am getting more out of Rex Paige's Two Dozen Short
Lessons in Haskell. ( I am studying Haskell and C# on my
own in my spare time as break from my medical practice ).
What did you find unuseful about GITH? How could it be
improved? What were
your expectations for it? What was more useful about Rex
Paige's notes?
I read part of _GITH,_ too; while it included information necessary for an
introduction, the style seemed rather terse and dry, and rather difficult to follow at
times, and read more like a manual with many technical details than a tutorial
brimming with motivational material, especially when compared to _The Haskell School
of Expression_ ("_HSE_" in the sequel). In particular, it could have had some more
interesting examples or some more commentary, both of which made _HSE_ so fascinating.
"Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo
Basho
Translation please !
Is it OK if I show off and steal some thunder? :)
"(It's) An old pond! The sound of water steadily
dripping in..."
Actually, if I may add, the translation I remember was the following:
"[It's] An old pond! The sound of water as the frog jumps in"
"Kawazu" means "frog," and "tobikomu" means "(to) jump in."
--Ben
--
Benjamin L. Russell
[EMAIL PROTECTED]
[EMAIL PROTECTED]
"Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho
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Re: Learning Haskell and FP
On Thu, 28 Dec 2000, Benjamin L. Russell wrote: On Thu, 28 Dec 2000 16:48:57 +0100 Frank Atanassow [EMAIL PROTECTED] wrote: i r thomas wrote (on 28-12-00 12:50 +1000): "Furuike ya! Kawazu tobikomu mizu no oto." --Matsuo Basho "(It's) An old pond! The sound of water steadily dripping in..." "[It's] An old pond! The sound of water as the frog jumps in" Keeping with the minimalistic spirit of Haskell: pond frog plop! -- by James Kirkup, an English poet -- Supposedly from Hiroaki Sato collection of 80 English translations -- of this haiku. -- 3 down 77 to go.. Jan ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
Re: Learning Haskell and FP
[ Doug Ransom wrote about wanting a more advanced and design-oriented book on FP than "The Craft of Functional Programming" by Simon Thompson. In reply, Johan Jeuring recommended the Advanced Schools books (I concur). ] Let me add a few other recommendations, plus a vision of a book (not yet written, as far as I know) which might fit Doug's needs; I'll call it "The Design Patterns Haskell Companion" (see below). The "actual book" recommendations (all documented on haskell.org): * Introduction to Functional Programming using Haskell (second edition) by Richard Bird (Prentice Hall, ISBN: 0-13-484346-0) This book is an introductory text, like CFP, but it ramps up a bit faster and addresses design issues from a more advanced perspective (IMHO). It's certainly an excellent text, and it builds to a nice medium-sized design example (the program calculator of Chapter 12). It also leans toward a different style of design and programming, influenced by BMF/Squiggol. * Algebra of Programming by Richard Bird and Oege de Moor (Prentice Hall, ISBN: 0-13-507245-X) You might think of this as an advanced sequel to IFPH above, although it focuses more on the theory behind program calculation: categories and allegories figure prominently, and it leans even further in the direction indicated above. But there is nevertheless a lot of good material here which can serve as a foundation for design work, esp. the final chapters (7-10) on algorithms topics. * Algorithms: A Functional Programming Approach by Fethi Rabhi and Guy Lapalme (Addison-Wesley, ISBN: 0-201-59604-0) This is a concise tour through the usual gamut of data structures and algorithms topics typical of a "CS 2" course, but from a functional perspective. It is addressed more to people who are already familiar with programming and with the "standard" approach to DSA issues. It works very well as a reference but includes enough discussion to reward a straight reading. * Purely Functional Data Structures by Chris Okasaki (Cambridge University Press, ISBN: 0-521-66350-4) This one is similar to AFPA above (in being a tour of DSA topics from a functional perspective), but is a bit more advanced: e.g., Ch. 3 covers leftist heaps, binomial heaps and red-black trees. It also addresses issues of analysis in the context of lazy evaluation more thoroughly (Banker's method, etc.). The examples are written using SML, but an appendix (and a website) give Haskell versions. Of course, none of these books really answers the needs of the mature programmer/blossoming functional programmer who seeks advice on broader design issues in the context of lazy FP, esp. Haskell. This gap leads me to propose the fanciful book mentioned above: * The Design Patterns Haskell Companion by [someone(s) reading this list?] The title may be pandering a bit, but if the Smalltalk people can do it, why can't we? :) . In fact, the title is based on "The Design Patterns Smalltalk Companion" by Alpert, Brown and Woolf, a book I came across while reading up on design patterns. (It was recommended by a customer review on Amazon as being better than the original "gang of four" book.) The "Smalltalk Companion" serves an audience of mature programmers and attempts to document a number of "standard" design patterns in the specific context of Smalltalk. I'm not sure that the Haskell community would be comfortable referring to its collective design folklore in these terms, but I'm sure we would all welcome a good book written at this level which systematically addressed the motivation, rationale, trade-offs, etc. of the more advanced techniques of FP (i.e., monads, type and constructor classes, Xa-morphisms (for various X), higher-order and nested datatypes, etc.). As Johan mentioned, the "Advanced School" books serve this purpose to an extent, but they differ from my vision in two respects: first, they are collections of chapters on particular topics, written by different authors, and thus don't form a consistent, systematic review. Second, they are not (all) written from the specific perspective of design, so that for example they don't provide as much comparison and contrast *between* techniques. Of course, another motivation for such a book is that it might lend an air of credibility and maturity to the language, thus helping to promote it in the larger world. Casting it in terms of "design patterns" would certainly make sense for these purposes (and probably guarantees a certain audience, too), although I am still ambivalent about the need for Haskell to become a huge hit with mainstream audiences. In any case, if anyone is interested to write such a book, I will buy a copy :) . And if anyone wishes to collabrate on it, I am willing to help out. (I am not qualified to write it alone, and I think it would turn out best as a group effort in any case.) -- Fritz Ruehr
Re: Learning Haskell and FP
I have read "The Craft of Functional Programming" by Simon Thompson and a few paper on the web. "The Craft" is a good book, but it is an introduction to FP. It seems to me it there are a lot of books on OO design I can pick up at the bookstore, but in the FP world, one must worm their way through all sorts of papers. I have seen papers on Catamorphisms, Monads, Programming with Barbed Wire, folds, etc. I think these papers are hard to understand if you don't have the acadademic/mathematical background -- being papers and not textbooks these papers assume a fair bit of base knowledge. I agree with this completely. The CFP book is a good introduction. Unforunately, the " Gentle Introduction To Haskell" that haskell.org links to is not a very useful introduction. I am getting more out of Rex Paige's Two Dozen Short Lessons in Haskell. ( I am studying Haskell and C# on my own in my spare time as break from my medical practice ). ___ Haskell mailing list [EMAIL PROTECTED] http://www.haskell.org/mailman/listinfo/haskell
