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Functional Programming at Facebook

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Re: Functional Programming at Facebook

#71

Post by catnaroek »

sova wrote: post #63
incepted wrote: post #43

Earlier quoted context omitted.

That's one of the many definitions we have for it, yes. Plenty of people will disagree with it too.

Please correct me if I am off the right track here, but is not the distinction the fact that: in a "functional language" or maybe "parenthentical up-cup evaluating language" functions are invoked in an encapsulating way, and no state is kept between function-cup-up-segments-of-code, but there is a R.E.P.L that (replies) when you invoke a (parens) which is, in LISP-land known as a program. However, now that I have min…

Functional programming is a programming paradigm that treats computation as the evaluation of mathematical functions. A function is a rule that assigns, to every element of its domain, a unique element of its codomain.

Note that the above definition says nothing about how functions are to be evaluated: strictly, lazily, memoizing previously computed results, or using magic. No general-purpose programming paradigm can make such decisions for the programmer.

Re: Functional Programming at Facebook

#72

Post by catnaroek »

dang wrote: post #60
catnaroek wrote: post #37

Earlier quoted context omitted.

> Lisp is just axioms. Do you even know what an axiom is? (In mathematical logic, of course.)

> Do you even Any comment that begins with that is unlikely to be a good fit for HN. Please post civilly and substantively, or not at all. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newswelcome.html

Not saying nonsense (“Lisp is just axioms”) is part of being civil.

Re: Functional Programming at Facebook

#73

Post by mbrock »

biokoda wrote: post #69
mbrock wrote: post #58

Earlier quoted context omitted.

Do you have references for the claim about telco switching?

That was the reason Erlang was created in the first place: https://en.wikipedia.org/wiki/Erlang_%28programming_language...

I know that. The last I heard was that Erlang decided to stop developing with Erlang, causing Armstrong and others to leave. I see they've reverses that decision and there are mentions of use at various mobile companies, so that's cool.

Re: Functional Programming at Facebook

#74

Post by mbrock »

querulous wrote: post #68
mbrock wrote: post #58

Earlier quoted context omitted.

Do you have references for the claim about telco switching?

http://erlang.se/publications/ericsson_review_axd301_1998012... erlang was literally developed for telephone switches

That's a product from the late nineties. I have no idea how broadly it's used today.

Re: Functional Programming at Facebook

#75

Post by querulous »

incepted wrote: post #66
SanFranManDan wrote: post #64

Earlier quoted context omitted.

Riot Games is a pretty big one. Looking at erlangs site selecting a few: AdRoll Facebook Chat TMobile http://erlang.org/faq/introduction.html Amazon SimpleDB Delicious From: http://stackoverflow.com/questions/1636455/where-is-erlang-u... Also many of the companies using Riak (written in Erlang) also leverage erlang. Some pretty big names use it. http://basho.com/about/customers/ I would say that Erlang has more than…

I was asking for the names of the experts allegedly behind Erlang. As for listing companies that use Erlang, plenty of companies use PHP and COBOL too. This doesn't say anything about whether these languages are the most adequate for the task and whether these projects wouldn't be in a better shape if written in a different language.

robert virding, richard o'keefe, francisco cesarini, mike williams, joe armstrong, ulf wiger, brian troutwine, fred hebert, jose vadim, steve vinoski, serge aleynikov?

Re: Functional Programming at Facebook

#76

Post by dang »

catnaroek wrote: post #72
dang wrote: post #60

Earlier quoted context omitted.

> Do you even Any comment that begins with that is unlikely to be a good fit for HN. Please post civilly and substantively, or not at all. https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newswelcome.html

Not saying nonsense (“Lisp is just axioms”) is part of being civil.

There's a big difference between being wrong and being abusive.

We don't want programming language flamewars on HN, so please don't conduct them here.

Re: Functional Programming at Facebook

#77

Post by catnaroek »

joostdevries wrote: post #65
catnaroek wrote: post #36

Earlier quoted context omitted.

I wouldn't call Scala a “functional” language. It's an object-oriented language that happens to be able to encode many Haskell idioms, with varying degrees of awkwardness. But you can write Java in Scala too, and, in the eyes of some, the result will even be more natural. Out of curiosity: Would you consider Prolog a language in which you can do “denotational” programming?

I would call Scala a functional language. In the sense that object-orientation and FP are not eachothers opposite. Imperative and FP are. I guess awkwardness is in the eye of the beholder. I think it's an elegant language with which it is a joy to develop large code bases.

I never said object-orientation and functional programming are opposites. (You can use objects to compute mathematical functions.) And, for that matter, imperative and functional programming aren't opposites either. (You can use imperative procedures to compute mathematical functions.) See: https://news.ycombinator.com/item?id=11180173 .

The awkwardness I'm talking about comes primarily from the non-orthogonality of Scala's features. For instance, there are situations where subclasses and implicits are both reasonable alternatives for a given programming task. On the other hand, in ML and Haskell, it is often clear which language feature is the right tool for the job.

Re: Functional Programming at Facebook

#79

Post by thinkpad20 »

incepted wrote: post #67
SanFranManDan wrote: post #64

Earlier quoted context omitted.

Riot Games is a pretty big one. Looking at erlangs site selecting a few: AdRoll Facebook Chat TMobile http://erlang.org/faq/introduction.html Amazon SimpleDB Delicious From: http://stackoverflow.com/questions/1636455/where-is-erlang-u... Also many of the companies using Riak (written in Erlang) also leverage erlang. Some pretty big names use it. http://basho.com/about/customers/ I would say that Erlang has more than…

> One aspect of it is that it is used more of an infrastructure language Ah yes, the "dark matter" argument. It's out there but nobody can see it. You'll just have to trust me.

You posted asking for evidence of erlang being a practical, widely-used programming language. The posts in response have provided a huge number of examples of erlang not just "in production" but critically so. And yet, you seem to be resignedly unimpressed; all of your follow-up posts seem to be in the form of shrugs and harrumphs. What more are you asking for?

Re: Functional Programming at Facebook

#80

Post by [deleted] »

abiox wrote: post #48
incepted wrote: post #30

Earlier quoted context omitted.

Sure, but I interpreted OP's statement as saying "used in practice" as in "used in the real world". Pretty sure that Erlang would barely register as a blip on such a chart.

RabbitMQ and CouchDB are written Erlang; Much of Ericsson's telephony infrastructure runs it; various companies in their industry like TMobile and Motorola use it.

[deleted]
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