8 ms·

Functional Programming Principles in Scala starts today

124 points by pohl 14y ago

Toshio 14y ago
Why does your submission get to the front page with 2 points, while mine[1] doesn't (mine also has 2 points and was submitted earlier)? [1] http://news.ycombinator.com/item?id=4537519 http://news.ycombinator.com/item?id=4537519
- Permit 14y ago
  The longer a post has been around, the most points it requires to get to the front page. I believe this is still relevant: http://amix.dk/blog/post/19574 http://amix.dk/blog/post/19574 PG's post: http://news.ycombinator.com/item?id=1781417 http://news.ycombinator.com/item?id=1781417
- crntaylor 14y ago
  I expect it's just luck. I submitted the same story and it also sank. Sometimes the gods of HN are kind to you, and sometimes they're cruel. Don't sweat it!
- lectrick 14y ago
  Are you interested in spreading knowledge, or are you interested in karma? If the former, why do you give a shit?
  - tych0 14y ago
    Perhaps he is interested in spreading knowledge. His post is basically identical to this one, but this one got selected. It's natural to want to understand why, rather than simply giving up. Indeed, if he comes to understand why, then knowledge has spread.
  - lmm 14y ago
    Isn't the whole point of displaying your karma score the way this site does to make you care about it? I know it works on me. I don't write the best comments I could, I write the ones I know will be upvoted.
    - exolab 14y ago
      Shame on you.
      - lmm 14y ago
        Meh. The community gets what it deserves based on what it votes for.
        gjm11 14y ago
        It is perfectly possible for both of the following to be true: (1) The community gets what it deserves. (2) Some of the people giving it what it deserves are behaving shamefully. (At least, it is if "gets what it deserves" means "gets something it's got no right to anything better than" rather than "gets exactly what, in some kind of best possible world, it would get".) Having said which, I don't think it's all that shameful to write what you think will get the most votes. But I'd rather you didn't.
      - liberatus 14y ago
        It's ironic. This is exactly the behavior that the system seems to want to avoid, but inevitably incentivizes. So shame on him? I don't know. Major props for being honest. One could argue you were subconsciously influenced toward posting a shaming comment because of the karma incentive. Of course, you may just be joking as well. It's certainly funny either way.
        exolab 14y ago
        I don't really care about Karma on this site (mine or other people's). If I did I certainly would have checked this comment earlier ;) If people post for Karma instead of for content, IMHO it is their problem. It won't make the site much better, but it won't make it much worse, either. "Shame on you" was my way of saying "who cares?".
  - eli_awry 14y ago
    Because the algorithms determining the content we consume are incredibly important in understanding the systematic biases of the information we internalize?
eranation 14y ago
One nice thing is that the instructor is Martin Odersky (who created the language).
dkhenry 14y ago
This looks to be a really good class. I watched part of the first lecture today and it really is more about functional programming then Scala.
- jzawodn 14y ago
  Good to hear. I signed up a few days ago and expect to start tomorrow.
pohl 14y ago
So far I'm liking the way the course material is structured. In the first week Martin is guiding you through call-by-name and call-by-value in the lamda calculus, but without its syntactic peculiarities and without really mentioning lamda calculus more than once in passing. I think this is a good idea, because lambda seems to raise defense mechanisms in students who are seeing it for the first time. Sneaky. Edit: I found a place where the web-based quiz mechanism used by Coursera gave me some troubles. In lecture 1.4 there is an exercise to implement functions and(x,y) and or(x,y) but using neither || nor &&. While I was able to compile and run functions that produce correct truth-tables in my Eclipse environment, the web-based form appears to be fairly tempermental with what it will accept. (Equivalent functions modulo only formatting differences made the difference between "incorrect" and "correct".) I managed to proceed by asking myself whether my function was as simple as possible: no newlines, simplest possible expression, no superfluous characters such as {}
bad_user 14y ago
Some of the Coursera courses rock. In March I also attended the NLP course. Another course on compilers from Stanford is coming up.
- saryant 14y ago
  I have a backlog of courses on Coursera. Right now it's this one, the NLP course and Andrew Ng's ML course. I have a project in mind that would benefit greatly from all three. I've started putting it together in small pieces but ML and NLP are tough topics to learn without some sort of instruction. I have a pretty good grasp of Scala but I learned in sort of an ad-hoc fashion and I'm looking forward to learning what I imagine will be idiomatic Scala.
  - coopdog 14y ago
    Andrew Ng's course ideally excellent, he's a very good lecturer. I'm liking this course too, it's really about functional programming more than Scala. He says in the first lecture that the curriculum is mostly from a well known book on scheme, just with the languages swapped out.
- denzil_correa 14y ago
  The NLP course needs some improvement in particular the Chris Manning sections. It was allow over the internal discussion forums. Dan Jurafsky was very good, can't say the same about Chris Manning.
  - jerry2yu 14y ago
    Agree! It would be great if more examples are provided in Prof. Manning's lectures.
theo 14y ago
For those in the DC area, the Scala DC meetup group is holding meetups to watch these lectures and discuss the material over the next few weeks. http://www.meetup.com/dc-scala http://www.meetup.com/dc-scala
- dkhenry 14y ago
  If anyone further North in Delaware wants to hold a meetup I have a group of about 10 software engineers getting together to watch the assignments.
msie 14y ago
Weird, aside from the first email in August I've had no email notification that it would start today. The only way I knew about it was through HN.
- brunov 14y ago
  I received an email yesterday and another one this morning.
pohl 14y ago
The "Scala Worksheet" feature of the Scala IDE plugin sounds pretty nice. Apparently it's a multi-line REPL, where changes automatically get compiled & evaluated upon save. I'm having some trouble figuring out how to get it installed in my Eclipse, though. I already had an older version of Scala IDE installed, and apparently this is a fairly new feature. I tried the latest milestone, which is supposed to have it, but I don't see New --> Scala Worksheet when I try to create one. Has anybody fought this dragon and won? Edit: I have found my own answer. The trick was to use the following URL as the "update site" when installing ScalaIDE. When you do, the "Scala Worksheet" plugin will appear under the list of available software. http://download.scala-ide.org/ecosystem/dev-milestone-2.9/site/ http://download.scala-ide.org/ecosystem/dev-milestone-2.9/si...
- nradov 14y ago
  Unfortunately the Scala IDE doesn't yet work with Eclipse Juno. Eclipse made a breaking API change. It's a shame they can't provide better backward compatibility; every new Eclipse release seems to break a lot of plugins. https://github.com/scala-ide/scala-ide/pull/145 https://github.com/scala-ide/scala-ide/pull/145
  - eranation 14y ago
    I managed to install on Juno. I tried the following and all worked: http://download.scala-ide.org/ecosystem/dev-milestone-2.9/site/ http://download.scala-ide.org/ecosystem/dev-milestone-2.9/si... (includes both IDE and the worksheet, which I wouldn't give up on) Also the specific Juno one: http://download.scala-ide.org/releases-juno-29/milestone/site http://download.scala-ide.org/releases-juno-29/milestone/sit... but it doesn't have the worksheet feature both worked for me on the latest Juno release p.s. I did have some issues, and uninstalling and reinstalling did the trick
    - zukhan 14y ago
      Actually the first link didn't work for me on Juno (because of jdt dependency issues). The following update sites worked: Scala IDE: http://download.scala-ide.org/nightly-update-juno-master-29x http://download.scala-ide.org/nightly-update-juno-master-29x Worksheet: http://download.scala-ide.org/nightly-build-worksheet-scalaide21-29/site/ http://download.scala-ide.org/nightly-build-worksheet-scalai...
sandGorgon 14y ago
Curious about something - if you had to do a new project from scratch today on top of the JVM, which language would you choose: clojure, scala, jruby (or anything else). I ask because my brain really cant absorb too many languages, and I want to make some kind of pseudo-optimal choice. I'm not just talking about some shootout here, but about the the next 5 years outlook.
- jbooth 14y ago
  If you haven't done JVM stuff before, it's probably best to start with the terribly unfashionable Java 1.6. All of the other JVM languages tend to use its library to large extent and are using a VM which was developed for Java first, so it's good to be familiar with the underlying landscape before exploring the different riffs on it. After that, if you want to switch to another JVM language, do it, but you should have a much clearer reason than "I want to use an alternative JVM language". Something about that language should grab you. Personally, I think Groovy's great for perl-type work where you'd like to just clack something out in a terminal rather than starting up a new project in eclipse. Clojure is an actual LISP for real functional programming. Scala (IMO, no offense) is a pile of academic features that sound great in theory. Jruby is ruby.
- ebiester 14y ago
  We moved node.js to Scala and play for our startup. I've programmed in grails (groovy) professionally and don't recommend it. I've heard good this about clojure but you either are a lisp fan or you aren't. As such, I don't think closure is the next big thing. I am not a fan of the required cognitive overhead that scala takes to get started -- reading someone else's code reminds me a lot of C++ and the tooling still needs to catch up. If any of the JVM languages are going to break out, I'd put my money on scala. JRuby has its place as well, and I know of a few high profile projects done in it, so it wouldn't be a bad choice for consumer apps. For enterprise, I think static typing has some major wins. I kind of want Scala--, to be honest...
  - eranation 14y ago
    I want it to be Scala so much as well, I don't want to start learning Go. (Although I heard great things about it, just after learning Scala, I don't want to learn a new language for a few years now)
signa11 14y ago
I am kind of discouraged by following post by Guido on scala : http://neopythonic.blogspot.in/2008/11/scala.html?m=1 http://neopythonic.blogspot.in/2008/11/scala.html?m=1. but perhaps this course would be sufficiently generic to not get bogged down by scala's peculiarities...
- pohl 14y ago
  That was interesting, thank you for linking to it. At first he seemed to be reacting more to Odersky's book than to the language. I wonder if he had first opened "Scala For The Impatient" how his reaction would be different. Then he takes the odd tack of complaining about arcana in the Scala typesystem, and then suggests Haskell as a solution. I get the impression that his love of dynamic typing had his mind made up before he even approached it.
  - wonderzombie 14y ago
    What does Haskell have to do with dynamic typing? It's about as statically typed as they come. He's saying that if we really want a static typing system, maybe Haskell's flexible and powerful type system is the right approach.
    - pohl 14y ago
      It doesn't have anything to do with it. I probably phrased it badly because I was responding to two different paragraphs where Guido was talking about different things. You would be better served following the link to what he wrote and reading that directly.
      - wonderzombie 14y ago
        I did read it, actually. :) That is why I was puzzled; he suggests Haskell as an alternative, and I thought that was a classy response, all things considered.
  - jimbokun 14y ago
    "Then he takes the odd tack of complaining about arcana in the Scala typesystem, and then suggests Haskell as a solution." What's odd about it? He seems to be straightforwardly claiming that Haskell has a less confusing type system than Scala. I don't know whether that's true or false, but certainly don't see anything odd about it.
qwertyz 14y ago
It's a shame the videos don't have subtitles like in the crypto course.
- modersky 14y ago
  Subtitles are being produced. They should be up in a day or two.
  - qwertyz 14y ago
    Oh, good to know. As non native english speaker they are of great help.
mark_l_watson 14y ago
I enrolled and have watched the first few videos. So far, I really like Martin's tidy scientific approach to functional programming. To be transparent I had intended to just take part of the course to get a taste because I am in one other class now and I have a total of three starting in the next few weeks. A combination of Clojure, Ruby, and Java more than suffice to get my work done, but I will probably stick with this class and drop other classes instead.
pva 14y ago
I am unable to submit from the command prompt on Windows (when in sbt). I completed assignment 1. I get the below error. > submit login password [error] Not a valid key: submit What am I missing ?

124 points by pohl 14y ago

Why does your submission get to the front page with 2 points, while mine[1] doesn't (mine also has 2 points and was submitted earlier)? [1] http://news.ycombinator.com/item?id=4537519 http://news.ycombinator.com/item?id=4537519

Permit 14y ago
The longer a post has been around, the most points it requires to get to the front page. I believe this is still relevant: http://amix.dk/blog/post/19574 http://amix.dk/blog/post/19574 PG's post: http://news.ycombinator.com/item?id=1781417 http://news.ycombinator.com/item?id=1781417
crntaylor 14y ago
I expect it's just luck. I submitted the same story and it also sank. Sometimes the gods of HN are kind to you, and sometimes they're cruel. Don't sweat it!
lectrick 14y ago
Are you interested in spreading knowledge, or are you interested in karma? If the former, why do you give a shit?
- tych0 14y ago
  Perhaps he is interested in spreading knowledge. His post is basically identical to this one, but this one got selected. It's natural to want to understand why, rather than simply giving up. Indeed, if he comes to understand why, then knowledge has spread.
- lmm 14y ago
  Isn't the whole point of displaying your karma score the way this site does to make you care about it? I know it works on me. I don't write the best comments I could, I write the ones I know will be upvoted.
  - exolab 14y ago
    Shame on you.
    - lmm 14y ago
      Meh. The community gets what it deserves based on what it votes for.
      - gjm11 14y ago
        It is perfectly possible for both of the following to be true: (1) The community gets what it deserves. (2) Some of the people giving it what it deserves are behaving shamefully. (At least, it is if "gets what it deserves" means "gets something it's got no right to anything better than" rather than "gets exactly what, in some kind of best possible world, it would get".) Having said which, I don't think it's all that shameful to write what you think will get the most votes. But I'd rather you didn't.
    - liberatus 14y ago
      It's ironic. This is exactly the behavior that the system seems to want to avoid, but inevitably incentivizes. So shame on him? I don't know. Major props for being honest. One could argue you were subconsciously influenced toward posting a shaming comment because of the karma incentive. Of course, you may just be joking as well. It's certainly funny either way.
      - exolab 14y ago
        I don't really care about Karma on this site (mine or other people's). If I did I certainly would have checked this comment earlier ;) If people post for Karma instead of for content, IMHO it is their problem. It won't make the site much better, but it won't make it much worse, either. "Shame on you" was my way of saying "who cares?".
- eli_awry 14y ago
  Because the algorithms determining the content we consume are incredibly important in understanding the systematic biases of the information we internalize?

eranation 14y ago

One nice thing is that the instructor is Martin Odersky (who created the language).

dkhenry 14y ago

This looks to be a really good class. I watched part of the first lecture today and it really is more about functional programming then Scala.

jzawodn 14y ago
Good to hear. I signed up a few days ago and expect to start tomorrow.

pohl 14y ago

So far I'm liking the way the course material is structured. In the first week Martin is guiding you through call-by-name and call-by-value in the lamda calculus, but without its syntactic peculiarities and without really mentioning lamda calculus more than once in passing. I think this is a good idea, because lambda seems to raise defense mechanisms in students who are seeing it for the first time. Sneaky. Edit: I found a place where the web-based quiz mechanism used by Coursera gave me some troubles. In lecture 1.4 there is an exercise to implement functions and(x,y) and or(x,y) but using neither || nor &&. While I was able to compile and run functions that produce correct truth-tables in my Eclipse environment, the web-based form appears to be fairly tempermental with what it will accept. (Equivalent functions modulo only formatting differences made the difference between "incorrect" and "correct".) I managed to proceed by asking myself whether my function was as simple as possible: no newlines, simplest possible expression, no superfluous characters such as {}

bad_user 14y ago

Some of the Coursera courses rock. In March I also attended the NLP course. Another course on compilers from Stanford is coming up.

saryant 14y ago
I have a backlog of courses on Coursera. Right now it's this one, the NLP course and Andrew Ng's ML course. I have a project in mind that would benefit greatly from all three. I've started putting it together in small pieces but ML and NLP are tough topics to learn without some sort of instruction. I have a pretty good grasp of Scala but I learned in sort of an ad-hoc fashion and I'm looking forward to learning what I imagine will be idiomatic Scala.
- coopdog 14y ago
  Andrew Ng's course ideally excellent, he's a very good lecturer. I'm liking this course too, it's really about functional programming more than Scala. He says in the first lecture that the curriculum is mostly from a well known book on scheme, just with the languages swapped out.
denzil_correa 14y ago
The NLP course needs some improvement in particular the Chris Manning sections. It was allow over the internal discussion forums. Dan Jurafsky was very good, can't say the same about Chris Manning.
- jerry2yu 14y ago
  Agree! It would be great if more examples are provided in Prof. Manning's lectures.

theo 14y ago

For those in the DC area, the Scala DC meetup group is holding meetups to watch these lectures and discuss the material over the next few weeks. http://www.meetup.com/dc-scala http://www.meetup.com/dc-scala

dkhenry 14y ago
If anyone further North in Delaware wants to hold a meetup I have a group of about 10 software engineers getting together to watch the assignments.

msie 14y ago

Weird, aside from the first email in August I've had no email notification that it would start today. The only way I knew about it was through HN.

brunov 14y ago
I received an email yesterday and another one this morning.

pohl 14y ago

The "Scala Worksheet" feature of the Scala IDE plugin sounds pretty nice. Apparently it's a multi-line REPL, where changes automatically get compiled & evaluated upon save. I'm having some trouble figuring out how to get it installed in my Eclipse, though. I already had an older version of Scala IDE installed, and apparently this is a fairly new feature. I tried the latest milestone, which is supposed to have it, but I don't see New --> Scala Worksheet when I try to create one. Has anybody fought this dragon and won? Edit: I have found my own answer. The trick was to use the following URL as the "update site" when installing ScalaIDE. When you do, the "Scala Worksheet" plugin will appear under the list of available software. http://download.scala-ide.org/ecosystem/dev-milestone-2.9/site/ http://download.scala-ide.org/ecosystem/dev-milestone-2.9/si...

nradov 14y ago
Unfortunately the Scala IDE doesn't yet work with Eclipse Juno. Eclipse made a breaking API change. It's a shame they can't provide better backward compatibility; every new Eclipse release seems to break a lot of plugins. https://github.com/scala-ide/scala-ide/pull/145 https://github.com/scala-ide/scala-ide/pull/145
- eranation 14y ago
  I managed to install on Juno. I tried the following and all worked: http://download.scala-ide.org/ecosystem/dev-milestone-2.9/site/ http://download.scala-ide.org/ecosystem/dev-milestone-2.9/si... (includes both IDE and the worksheet, which I wouldn't give up on) Also the specific Juno one: http://download.scala-ide.org/releases-juno-29/milestone/site http://download.scala-ide.org/releases-juno-29/milestone/sit... but it doesn't have the worksheet feature both worked for me on the latest Juno release p.s. I did have some issues, and uninstalling and reinstalling did the trick
  - zukhan 14y ago
    Actually the first link didn't work for me on Juno (because of jdt dependency issues). The following update sites worked: Scala IDE: http://download.scala-ide.org/nightly-update-juno-master-29x http://download.scala-ide.org/nightly-update-juno-master-29x Worksheet: http://download.scala-ide.org/nightly-build-worksheet-scalaide21-29/site/ http://download.scala-ide.org/nightly-build-worksheet-scalai...

sandGorgon 14y ago

Curious about something - if you had to do a new project from scratch today on top of the JVM, which language would you choose: clojure, scala, jruby (or anything else). I ask because my brain really cant absorb too many languages, and I want to make some kind of pseudo-optimal choice. I'm not just talking about some shootout here, but about the the next 5 years outlook.

jbooth 14y ago
If you haven't done JVM stuff before, it's probably best to start with the terribly unfashionable Java 1.6. All of the other JVM languages tend to use its library to large extent and are using a VM which was developed for Java first, so it's good to be familiar with the underlying landscape before exploring the different riffs on it. After that, if you want to switch to another JVM language, do it, but you should have a much clearer reason than "I want to use an alternative JVM language". Something about that language should grab you. Personally, I think Groovy's great for perl-type work where you'd like to just clack something out in a terminal rather than starting up a new project in eclipse. Clojure is an actual LISP for real functional programming. Scala (IMO, no offense) is a pile of academic features that sound great in theory. Jruby is ruby.
ebiester 14y ago
We moved node.js to Scala and play for our startup. I've programmed in grails (groovy) professionally and don't recommend it. I've heard good this about clojure but you either are a lisp fan or you aren't. As such, I don't think closure is the next big thing. I am not a fan of the required cognitive overhead that scala takes to get started -- reading someone else's code reminds me a lot of C++ and the tooling still needs to catch up. If any of the JVM languages are going to break out, I'd put my money on scala. JRuby has its place as well, and I know of a few high profile projects done in it, so it wouldn't be a bad choice for consumer apps. For enterprise, I think static typing has some major wins. I kind of want Scala--, to be honest...
- eranation 14y ago
  I want it to be Scala so much as well, I don't want to start learning Go. (Although I heard great things about it, just after learning Scala, I don't want to learn a new language for a few years now)

signa11 14y ago

I am kind of discouraged by following post by Guido on scala : http://neopythonic.blogspot.in/2008/11/scala.html?m=1 http://neopythonic.blogspot.in/2008/11/scala.html?m=1. but perhaps this course would be sufficiently generic to not get bogged down by scala's peculiarities...

pohl 14y ago
That was interesting, thank you for linking to it. At first he seemed to be reacting more to Odersky's book than to the language. I wonder if he had first opened "Scala For The Impatient" how his reaction would be different. Then he takes the odd tack of complaining about arcana in the Scala typesystem, and then suggests Haskell as a solution. I get the impression that his love of dynamic typing had his mind made up before he even approached it.
- wonderzombie 14y ago
  What does Haskell have to do with dynamic typing? It's about as statically typed as they come. He's saying that if we really want a static typing system, maybe Haskell's flexible and powerful type system is the right approach.
  - pohl 14y ago
    It doesn't have anything to do with it. I probably phrased it badly because I was responding to two different paragraphs where Guido was talking about different things. You would be better served following the link to what he wrote and reading that directly.
    - wonderzombie 14y ago
      I did read it, actually. :) That is why I was puzzled; he suggests Haskell as an alternative, and I thought that was a classy response, all things considered.
- jimbokun 14y ago
  "Then he takes the odd tack of complaining about arcana in the Scala typesystem, and then suggests Haskell as a solution." What's odd about it? He seems to be straightforwardly claiming that Haskell has a less confusing type system than Scala. I don't know whether that's true or false, but certainly don't see anything odd about it.

qwertyz 14y ago

It's a shame the videos don't have subtitles like in the crypto course.

modersky 14y ago
Subtitles are being produced. They should be up in a day or two.
- qwertyz 14y ago
  Oh, good to know. As non native english speaker they are of great help.

mark_l_watson 14y ago

I enrolled and have watched the first few videos. So far, I really like Martin's tidy scientific approach to functional programming. To be transparent I had intended to just take part of the course to get a taste because I am in one other class now and I have a total of three starting in the next few weeks. A combination of Clojure, Ruby, and Java more than suffice to get my work done, but I will probably stick with this class and drop other classes instead.

pva 14y ago

I am unable to submit from the command prompt on Windows (when in sbt). I completed assignment 1. I get the below error. > submit login password [error] Not a valid key: submit What am I missing ?