As an aside, Scala is not unique in marrying a FP approach with an OO system. CL has had CLOS, IMO one of the better implementations of "OO" outside of Smalltalk, for much longer than Scala.
Definitely watch this!
As an aside, CLOS multimethods resemble Haskell's multiparameter type classes (except CLOS is dumber: you cannot provide any guarantee that the same types will provide two or more common operations) more than they resemble anything else also called "object-oriented".
The best descriptor I can find to date (of CL) is, "programmable programming language," which allows it to encompass almost every desired feature one may need; including many that fall under the FP umbrella which may be where the confusion stems from.
However one of the opening points of the talk was that, "FP," is not a rigorously defined term and is subject to interpretation. Which leads to bikeshedding over language features and a lot of hype.
I believe it also leads to a lot of misplaced faith in the purity and completeness of mathematics (it's almost as if the popular notion of FP is being reborn as a modern Principia Mathematica).
CL obviously cannot be called an, "FP," language since its inception seems to predate the popular notion of the term. Scala may suffer in the same way due to its reliance on the JVM and the expression semantics it has carried over from Java. However many of the features one tends to associate with modern FP languages (though not all) are present in both languages.
As for your aside, how so? Perhaps a discussion we can have over email if you're interested. You sound smart. However I don't understand your statement and would like to know more.
CLOS multimethods do not "belong" to an object or even to a class declaration. Particular implementations of generic methods are declared globally, just like Haskell type class instances. Although, as Peaker noted, type classes can dispatch on any part of the type signature. It is impossible to make a CLOS multimethod with signature:
(SomeClass a b) => String -> (a, b)
Sorry, I never check email. But I am almost always on Freenode. My nick is pyon.
> You sound smart.
Not really. The regulars in #haskell - now they are frigging smart.
> Not really. The regulars in #haskell - now they are frigging smart.
Don't sell yourself short.
I thought it was brilliant because Gilad provides a humble deconstruction of common myths and claims of the FP culture. He is skeptical and I didn't find any of his conclusions to be dismissive: he walks through the reasoning behind his opinions. I certainly didn't find any point where I thought he was ignorant of the subject of which he was speaking. And if you listen to his opening remarks about "deconstruction," and his conclusion do note that he points out some FP concepts that are useful and should be exploited more. He was there to break through the hype and I think he was successful.
He argued with a joke from a comic and lost. Even he would laugh in your face at the notion that there was anything humble about his talk.
>He is skeptical and I didn't find any of his conclusions to be dismissive
That is precisely the opposite of reality. He doesn't even understand functional programming, he is thus not skeptical, he is dismissive.
>He was there to break through the hype and I think he was successful.
The fact that both he and you believe there is "hype" is indicative of the problem. "Hey, you should learn things and improve your skills" is not hype.
Most of what he says is outright wrong. He talks about smalltalk inventing all of this FP stuff that was in ML before smalltalk-76 "invented" them. He pretends smalltalk predates FP, except again, ML predates smalltalk-76. and smalltalk-72 didn't have the stuff he is talking about. He talks about things "FP languages can't do", but that I do all the time in haskell with no issues. He repeats the oldest most worn out fallacious arguments that have been debunked over and over, and pretends that since nobody is allowed to interrupt the talk to correct him, his arguments are correct. Everything about his talk is an example of the exact opposite of what you suggest it is. If you want someone to convincingly lie to you about how FP isn't all that, look to Erik Meijer. Gilad sucks at it.