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Advanced programming languages

matt.might.net

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Re: Advanced programming languages

#11

Post by jorgeortiz85 »

terra_t wrote: post #3

Some thoughts. The people I know who do work in machine learning (Jon Kleinberg, Thorsten Joachims, and their students) work in straight-up C, not Haskell, as the author suggests. Most of the dominant methods used today, such as the SVM, boosting, and the dynamic programming methods used in genomics are (i) numerical more than symbolic and (ii) involve moving a LOT of data around, so you want control of your data str…

Starting with version 2.7.2, Scala added an experimental feature (which will no longer be experimental as of 2.8.0) called Manifests that allow you to selectively reify erased types. See this blog post for more: http://www.scala-blogs.org/2008/10/manifests-reified-types.h...

This, combined with specialization (compiling primitive-specialized versions of code with generic types to improve performance of, for example, using function types on primitive collections) will make it easier to write performant, numeric code in Scala than in any other JVM language (up to the limits of the JVM, of course).

The NLP communities at Stanford and Berkeley, which do a fair amount of machine learning, have a long history of working in Java (http://nlp.stanford.edu/software/, http://nlp.cs.berkeley.edu/Main.html#Software) and have recently started using Scala as well (http://www.scalanlp.org/).

Scala's interface with Java collections IS a bit clunky. Thankfully, this is a library issue, not a language issue, and can be solved with better libraries. See http://github.com/jorgeortiz85/scala-javautils (for Scala 2.7.x) and http://github.com/scalaj/scalaj-collection (for Scala 2.8.x).

Re: Advanced programming languages

#12

Post by sid0 »

terra_t wrote: post #3

Some thoughts. The people I know who do work in machine learning (Jon Kleinberg, Thorsten Joachims, and their students) work in straight-up C, not Haskell, as the author suggests. Most of the dominant methods used today, such as the SVM, boosting, and the dynamic programming methods used in genomics are (i) numerical more than symbolic and (ii) involve moving a LOT of data around, so you want control of your data str…

Yeah, it's clear that more than a bit of PL research has fed back into C# as a language and .NET as a whole, in stark contrast to Java/JVM.

Re: Advanced programming languages

#13

Post by sreque »

terra_t wrote: post #3

Some thoughts. The people I know who do work in machine learning (Jon Kleinberg, Thorsten Joachims, and their students) work in straight-up C, not Haskell, as the author suggests. Most of the dominant methods used today, such as the SVM, boosting, and the dynamic programming methods used in genomics are (i) numerical more than symbolic and (ii) involve moving a LOT of data around, so you want control of your data str…

Scala 2.8 has manifests, which reify generic types. What do you wish you could do with reified types that you can't do with manifests?

Also, in Scala 2.7 I wrote my own library to wrap Java collections that didn't take much time or effort and allowed me to seamlessly pass scala collections to java code and use java collections the same as scala ones. Scala 2.8 is supposed to have such a library built in so you don't have to write it.

Lastly, your comparison between Scala's functional lists and Java's ArrayList is pointless. Scala has an ArrayBuffer class too, so you can choose between either as appropriate. You can also pattern match against ArrayBuffer as well.

Re: Advanced programming languages

#14

Post by crux_ »

terra_t wrote: post #3

Some thoughts. The people I know who do work in machine learning (Jon Kleinberg, Thorsten Joachims, and their students) work in straight-up C, not Haskell, as the author suggests. Most of the dominant methods used today, such as the SVM, boosting, and the dynamic programming methods used in genomics are (i) numerical more than symbolic and (ii) involve moving a LOT of data around, so you want control of your data str…

> Another issue with Scala is that the interface with Java, particularly using collections, is awkward; [...]

Really? For me one of Scala's best attributes, by far, is the ability to use its implicit conversions to make awkward Java APIs smooth like butter.

> One problem is that, based on the JVM, type erasure is a big "broken window" that seriously damages the Scala type system.

I'm not sure I understand or agree. Understand: If you don't use casting, Scala's type system seems just as strong as ML, albeit not as good at inference. (F# has the exact same inference weakness as soon as you start using OO and inheritance.) Agree: having the ability to consciously drop into a dynamically typed/runtime-casted world for small bits of code is quite nice (true for F# too). And I've yet to see a place where erasure (a) caused, even in theory, a runtime type error, or (b) lost any type information within the scala language at compile or link time (which is where the type checking lives). I think it's a red herring / mere implementation detail.

> As for oCaml, the real excitement is in F#. You get the wonderful oCaml language and all of its features, plus you get an interface to the C#/.NET world that's much nicer than Scala's interface to the JVM.

Counterpoint: I've written production code in both Scala and F#; give me Scala any day of the week. I really wish its .NET support was more mature; I'd ditch it in a heartbeat for Scala if I could.

Re: Advanced programming languages

#15

Post by dpritchett »

KirinDave wrote: post #5

And a strong sell for Scala and no mention of Clojure. It confuses the hell out of me; clojure is fast, mature, and has a OO syntax and model to rival CLOS. It's got built in laziness and te best concurrency primitives I've seen to date (and I was a professional Erlang programmer). What does it take to break into the general public's consciousness? Clearly it's not the parens.

Scala has Twitter to champion it in business and tech circles as well as creator Odersky's technical university affiliations to appeal to the academic crowd.

Clojure has a lot going for it in terms of theory but I don't know that it can claim any of the social proof of Scala.

The closest thing I can think of for Clojure is all of Siebel's Lispy interview questions from Coders at Work that lead an underinformed coder to think highly of STM and of Lisps.

Edit: Scala apparently predates Clojure by a good four years. The larger mindshare is no surprise in that light. Also it appears to have simple pattern matching and several other things that Alex Payne liked: http://www.slideshare.net/al3x/why-scala-presentation

Re: Advanced programming languages

#17

Post by jopamer »

Artemidoros wrote: post #8
terra_t wrote: post #3

Some thoughts. The people I know who do work in machine learning (Jon Kleinberg, Thorsten Joachims, and their students) work in straight-up C, not Haskell, as the author suggests. Most of the dominant methods used today, such as the SVM, boosting, and the dynamic programming methods used in genomics are (i) numerical more than symbolic and (ii) involve moving a LOT of data around, so you want control of your data str…

Note that there is a good open source implementation of the .NET framework, Mono, so you can develop in C# and F# and target Linux, MacOS and other platforms. Is Mono actually usable with F#? The last time I checked (2 months ago) the F# plugin for MonoDevelop didn't work and the questions on how to getting it to work (by various people) went unanswered by the developer. The runtime performance of F# code was shaky a…

[Disclaimer: I'm a compiler dev working on F# at MSFT.]

Performance and user experience on Mono are something we're definitely trying to improve - we spent a fair amount of time trying to make our Mono story better for our 2.0 release, and plan on investing more in this area as we move forward.

We can't be everywhere at once, so your feedback is really important here - If you're having problems with our tools on Mono, please let us know via Microsoft Connect or fsbugs@microsoft.com. Also, don't be bashful about filing Mono bugs. So far, they've been really great about responding to any issues that have cropped up.

Thanks!

Re: Advanced programming languages

#18

Post by jheriko »

I'm curious where all the data is about "expressiveness" being so important. I'm yet to meet the person who can churn out functional solutions quicker than imperative... but I hope this is my naivete and not just the CS bandwagon effect.

Re: Advanced programming languages

#19

Post by KirinDave »

francoisdevlin wrote: post #7
KirinDave wrote: post #5

And a strong sell for Scala and no mention of Clojure. It confuses the hell out of me; clojure is fast, mature, and has a OO syntax and model to rival CLOS. It's got built in laziness and te best concurrency primitives I've seen to date (and I was a professional Erlang programmer). What does it take to break into the general public's consciousness? Clearly it's not the parens.

I seriously think Clojure is too much to take in at the first introduction. It's really hard to get your brain around everything done right, when compared to traditional programming. You need to use it for a while to really get why it's approach to state (not concurrency) is awesome.

I think that this may be a side-effect of the literature, which is very lispy and computer sciency. For someone like me, that's exactly the right tack. For someone who may not take for granted all the claims Rich and his book-writing compatriots are making (let alone take for granted the lisp code-as-data is an foundational revelation of computer science), it may be a problem.

Because really, Clojure is in many ways simpler than both Scala and Java. You can ignore the hard parts (agents, deftype, macros, de-chunking seqs, etc) and just cruise through the easy parts with a fair degree of ease. Everyone understands functions, after all. And Javascript has really pushed the "use functions for everything" approach into the public eye quite nicely.

Re: Advanced programming languages

#20

Post by xtho »

dpritchett wrote: post #15
KirinDave wrote: post #5

And a strong sell for Scala and no mention of Clojure. It confuses the hell out of me; clojure is fast, mature, and has a OO syntax and model to rival CLOS. It's got built in laziness and te best concurrency primitives I've seen to date (and I was a professional Erlang programmer). What does it take to break into the general public's consciousness? Clearly it's not the parens.

Scala has Twitter to champion it in business and tech circles as well as creator Odersky's technical university affiliations to appeal to the academic crowd. Clojure has a lot going for it in terms of theory but I don't know that it can claim any of the social proof of Scala. The closest thing I can think of for Clojure is all of Siebel's Lispy interview questions from Coders at Work that lead an underinformed coder…

AFAIK the "theory" in clojure also stems from the scala world in that clojure data structures are based on work done for scala or by scala affiliates.
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