The Whiteboard

12:00 AM

Your comment was a bit charged, but... well... it's Meta, it wouldn't be any fun if things didn't get heated every now and then.

Jubbat

Hi. Do you think a language that can spark a long winded discussion on how to implement a simple algorithm such as the sieve of erastostenes (http://clj-me.cgrand.net/2009/07/30/everybody-loves-the-sieve-of-eratosthenes/) optimally can be really practical?

I'm just re-approaching Clojure recently (I tried learning before) but every time it seems like it's overly "flexible" to be practical, if that makes sense. Maybe I just don't get it or I'm not skilled enough. Am I misguided in thinking like this?

user55340

@Jubbat Personally, I like the Sieve of Sundaram.

user55340

Sieve of Sundaram

In mathematics, the sieve of Sundaram is a simple deterministic algorithm for finding all prime numbers up to a specified integer. It was discovered in 1934 by S. P. Sundaram, an Indian student from Sathyamangalam. Algorithm Start with a list of the integers from 1 to n. From this list, remove all numbers of the form i + j + 2ij where: *i,j\in\mathbb{N},\ 1 \le i \le j *i + j + 2ij \le n The remaining numbers are doubled and incremented by one, giving a list of the odd prime numbers (i.e., all primes except 2) below 2n + 2. The sieve of Sundaram sieves out the composite numbers just as s...

user55340

There are some neat bits with it that make it possibly more applicable in FP...

user55340

Poke at me and @JimmyHoffa discussing it back in April...

user55340

12:07 AM

Apr 17 at 17:31, by MichaelT

The thing I like about Sundaram is that it doesn't use any previous information to eliminate a non-prime. That may make it slower, but its also much simpler.

Jubbat

thanks, although I chose it as an example

rather than whether is the best prime finding algorithm

user55340

Lisps are very flexible languages, and practical too... it just takes a different way of thinking of things.

user55340

The biggest problem that you'll have is the... framework that people build up of macros to make it even easier to do things.

Yannis Rizos

I find the inherent flexibility of dynamic languages sometimes leads to analysis paralysis, especially with inexperienced developers. Having 50 ways of doing the same thing isn't always a good thing... I guess Clojure and Lisps in general could suffer from the same thing (although I wouldn't really know, I avoid Lisps like the plague)

user55340

If you ever happen to find a lisp (or Clojure) shop, and learn their way of doing things and then go to another one, it may be completely different because of that 'framework'.

Jubbat

12:12 AM

I watched the "simple vs easy" talk by Rich Hickey and I have the suspicion that it's a bit of a phallacy, I wonder if not having more constraints makes things harder, but again, maybe it's just my problem

I used to like common lisp, I did things in a more primitive way, but I struggle with clojure

user55340

(fallacy... a phallacy would be... well... an interesting root to work from... not that I'm a spelling master, I'm just smirking)

psr

fallacy? (otherwise the rest of that sentence reads... oddly).

Jubbat

oops English is not my mother tongue, sorry

user55340

@Jubbat No problem at all, I understood it... I'm just smirking too.

psr

@Jubbat - sorry to pile on. I hadn't seen MichaelT's last message yet.

Jubbat

12:15 AM

@Yannis why do you avoid lisps?

user55340

@Jubbat I honestly am often impressed at the mastery of english by non-native english speakers and applaud the work that you have done to become very proficient at it.

Yannis Rizos

@Jubbat Mostly cause I value my sanity ;)

user55340

(and to get the background as to why I'm smirking - en.wiktionary.org/wiki/phallic )

Jubbat

@MichaelT thank you :)

user55340

Apr 14 at 1:38, by MichaelT

Oh, another fun anecdote of language idioms... HS french teacher, when she was a exchange student in france the first time. Big dinner at the host family the first night. At the end, she pats her belly and says literally, "I am full" - Je suis plen. However, this translates to "I am pregnant." (the correct french is J'ai plen or "I have full") The host parents gave their son very harsh looks until this was cleared up.

user55340

12:18 AM

(just some fun I was reminded of with language confusion)

user55340

Some other language fun - from British English to American English is told in telegraph.co.uk/expat/4184879/…

user55340

Sep 19 at 19:47, by MichaelT

> My family and I moved to Arkansas from England two years ago as part of a company move. We were given all sorts of relocation assistance: someone to help find a house, to show us the schools, the athletic clubs etc. We were even sent a book called Hello! USA - Everyday Living for International Residents and Visitors. I dutifully read this from cover to cover and found out that Americans also shake hands, appreciate eye contact, and value personal hygiene and personal space.

user55340

Sep 19 at 19:48, by MichaelT

> Pants: This word refers to the outer-garments that cover your legs in the US. In the UK, pants are the undergarments worn beneath your trousers.

user55340

Anyways... lisp. The functional languages are often just so different than the more mainstream procedural / imperative approach to thinking about things. Setting up instructions of 'tell computer to do this' - we've got that mindset.

user55340

With functional languages, its... different.

Jubbat

12:22 AM

yes, functional style is more declarative

user55340

And its such a different thought, and the flexibility that comes with it that makes it quite challenging. However important things come from being able to make your mind that flexible (not sanity).

Jubbat

it doesn't come so naturally

user55340

Schwartzian transform

In computer science, the Schwartzian transform is a Perl programming idiom used to improve the efficiency of sorting a list of items. This idiom is appropriate for comparison-based sorting when the ordering is actually based on the ordering of a certain property (the key) of the elements, where computing that property is an intensive operation that should be performed a minimal number of times. The Schwartzian Transform is notable in that it does not use named temporary arrays. The idiom is named after Randal L. Schwartz, who first demonstrated it in Perl shortly after the release of Perl ...

user55340

@sorted = map  { $_->[0] }
          sort { $a->[1] <=> $b->[1] } # use numeric comparison
          map  { [$_, length($_)] }    # calculate the length of the string
               @unsorted;

user55340

That idea is very functional based.

user55340

12:23 AM

MapReduce

MapReduce is a programming model for processing large data sets with a parallel, distributed algorithm on a cluster. A MapReduce program comprises a Map() procedure that performs filtering and sorting (such as sorting students by first name into queues, one queue for each name) and a Reduce() procedure that performs a summary operation (such as counting the number of students in each queue, yielding name frequencies). The "MapReduce System" (also called "infrastructure", "framework") orchestrates by marshalling the distributed servers, running the various tasks in parallel, managing all co...

user55340

This has functional written all over it.

user55340

And so... just being aware of the idea of thinking of functions as first class things in the language is useful.

user41796

@YannisRizos - I had already walked away from the matter. His follow-up comment to me clearly indicated it was going to be an unproductive conversation. Thanks for the feedback.

user55340

Thinking functional, about sequences and immutable objects can make for some applications to have superior performance.

user55340

Random off topic - I just ordered String Railway - looks to be a neat game.

user55340

12:27 AM

amazon.com/String-Railway-Game-from-FoxMind/dp/B00AGYBYGE

user41796

@RobertHarvey - you wouldn't happen to know any mods on SO who could migrate the question here for a merge, would you? — GlenH7 32 secs ago

user55340

Jubbat

Aside from writing new code, I wonder if maintaining a system written in a functional language is really hellish

my understanding is that functional code is intrinsecally harder to read than imperative...

user55340

The off quoted post on that is Paul Graham's Beating the Averages post paulgraham.com/avg.html

user55340

Its different reading.

Jubbat

12:30 AM

Ah yes, I had read that one

I do enjoy lisp, my issue is more with clojure really, so just wanted to pick up your brains and see if it's really my lack of skill / experience

user55340

I've dabbled in clojure some.

user55340

Sep 5 at 19:42, by MichaelT

I still had my head explode when I realized I could use cycle in clojure to flip between functions

Yannis Rizos

In fact, I think browsing SO while drunk is quite popular. I think a lot of people are reluctant to post while they're drunk because they're afraid they'll say something stupid and get heavily downvoted, so they go and review suggested edits instead. That's the only way I can explain how so many ridiculous edit suggestions end up getting approved. — Adi Inbar 29 secs ago

He's on to something...

user55340

May 9 at 16:57, by MichaelT

(defn pi
  ([] (float (* 4 (pi 1 0.01 0 true))))
  ([term tol accum pn]
    (let
      [t (/ 1 term)
       a ((if pn + -) accum t)]
      (if (< (* 4 t) tol)
        a
        (pi (+ term 2) tol a (not pn))
      )
    )
  )
)

user55340

Ok... I've gotta get something to eat or my stomach will claw its way out of my belly and beat me over the head (its grumbling that loudly).

user41796

12:35 AM

@MichaelT - no doubt.

Yannis Rizos

:11412884 Closed. There's no point in migrating and merging if there are no answers.

user41796

@YannisRizos makes sense. Too bad I can't flag it and scream "BURN IT!"

Yannis Rizos

@GlenH7 Of course you can:

Jubbat

I have to leave now, thanks all for your input

Yannis Rizos

@GlenH7 Ah, he self-deleted it. Always nice when people clean up after themselves.

iBrazilian

1:52 AM

I'd like to combine CSS with C++, I plan on creating an application and I don't want to use Qt because it's not free, any ideas? It'll pretty much be a web app but for windows.

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