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PG on the cover of Forbes

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Re: PG on the cover of Forbes

#21

Post by axod »

jdp23 wrote: post #7

i thought the virtual absence of women was interesting. Jessica Mah got two paragraphs near the end, Demi Moore a passing mention, and Jessica Livingston merited two sentences. she co-founded YC and is married to Paul, and they couldn't even ask her for a quote? other than that it was guys, guys, guys. http://bit.ly/ycturgor2 has more.

That's because most founders are guys?

It's like the leaflet I got from our local hospital the other day. It features on the cover an african, an indian, a few other minorities, and one small white person. It's like they're trying way too hard to appear diverse. (The area it serves is probably 90%+ white).

I'd rather they project what is actually out there.

Re: PG on the cover of Forbes

#22

Post by axod »

j_baker wrote: post #19
evanrmurphy wrote: post #18

Earlier quoted context omitted.

> Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. How would you explain the Y Combinator to the Hacker News readership?

I wouldn't. I barely understand the concept myself. :-) ...but I know it's much more involved than "a program that runs other programs".

afaik it's pretty academic. The only practical application is to allow recursion in languages that don't do recursion which is pretty much none.

This is a good description if you're into that sort of thing: http://mvanier.livejournal.com/2897.html

The meat of it is that you can 'do' recursion by building up functions that call other functions :/ meh

Re: PG on the cover of Forbes

#23

Post by simplegeek »

axod wrote: post #22
j_baker wrote: post #19

Earlier quoted context omitted.

I wouldn't. I barely understand the concept myself. :-) ...but I know it's much more involved than "a program that runs other programs".

afaik it's pretty academic. The only practical application is to allow recursion in languages that don't do recursion which is pretty much none. This is a good description if you're into that sort of thing: http://mvanier.livejournal.com/2897.html The meat of it is that you can 'do' recursion by building up functions that call other functions :/ meh

>> The only practical application is to allow recursion in languages that don't do recursion which is pretty much none.

Above is a very hard sentence to parse for non-native speakers, just saying ;)

Re: PG on the cover of Forbes

#24

Post by eliben »

evanrmurphy wrote: post #18
j_baker wrote: post #2

"Y Combinator--a computer term for a program that runs other programs" Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. EDIT: And another one... "Graham met Morris, an authority on the Unix computer language"

> Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. How would you explain the Y Combinator to the Hacker News readership?

The Y combinator is a programming construct allowing one to write recursive functions without explicitly calling themselves (unnamed recursive functions):

  (define Y
   (lambda (X)
    ((lambda (procedure)
       (X (lambda (arg) ((procedure procedure) arg))))
     (lambda (procedure)
       (X (lambda (arg) ((procedure procedure) arg)))))))

  (define F*
   (lambda (func-arg)
    (lambda (n)
      (if (zero? n)
          1
          (* n (func-arg (- n 1)))))))

  (define fact (Y F*))
  (write (fact 8))
Note that F* is a label for a recursive factorial-computing function without a name.

Re: PG on the cover of Forbes

#25

Post by meastham »

evanrmurphy wrote: post #18
j_baker wrote: post #2

"Y Combinator--a computer term for a program that runs other programs" Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. EDIT: And another one... "Graham met Morris, an authority on the Unix computer language"

> Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. How would you explain the Y Combinator to the Hacker News readership?

Like others have mentioned it's rather academic, but also pretty cool. It's a way of introducing recursive functions into the untyped lambda calculus. I think the easiest way to see it is using it in scheme to define an anonymous recursive function:

  (((lambda (fact)
      ((lambda (f)
         (fact (lambda (n) ((f f) n))))
       (lambda (f)
         (fact (lambda (n) ((f f) n))))))
    (lambda (fact)
      (lambda (n)
        (if (= n  0)
          1
          (* n (fact (- n 1)))))))
   10)
Computes 10!

You'll notice that lines 6-10 define a procedure that takes a factorial function, performs one level of the recursion, and then calls the factorial function to compute the rest. The Y combinator, implemented in lines 1-5, basically allows us to start the recursion. A step by step derivation can be found at http://www.ece.uc.edu/~franco/C511/html/Scheme/ycomb.html

The really neat thing about this is that all that was required to create that factorial function was lambda, some arithmetic functions, and if. Arithmetic can be implemented using only lambdas (google church numerals) and so can if. Using these techniques you can create a factorial function using only lambda and function application (which is exactly the lambda calculus).

If you replace "program" in the Forbes article with "function" I don't think they're terribly far off.

Re: PG on the cover of Forbes

#26

Post by perlgeek »

evanrmurphy wrote: post #18
j_baker wrote: post #2

"Y Combinator--a computer term for a program that runs other programs" Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. EDIT: And another one... "Graham met Morris, an authority on the Unix computer language"

> Heh... completely wrong, but I suppose it's the best you can expect a non-techie/math nerd readership to get. Heck, it's probably close to the most you can expect the average programmer to get. How would you explain the Y Combinator to the Hacker News readership?

There have been explanations for the HN readers. Here's one that I'd put in a non-techy newspaper:

The Y Combinator is a way to make computer code self-referential without having to introduce names for parts of the code.

Or a bit less accurate:

The Y Combinator is a clever way to make computer code self-referential.

Re: PG on the cover of Forbes

#27

Post by cloudwalking »

cloudwalking wrote: post #20
gojomo wrote: post #8

Earlier quoted context omitted.

A nice, striking (against the red), somewhat atypical picture of PG. Did the photographer coach to suppress the usual smile?

His eyes are smiling, I bet he's about to crack up.

Why is this getting voted down? Look at the picture!

Re: PG on the cover of Forbes

#30

Post by RyanMcGreal »

cloudwalking wrote: post #27
cloudwalking wrote: post #20

Earlier quoted context omitted.

His eyes are smiling, I bet he's about to crack up.

Why is this getting voted down? Look at the picture!

His expression seems to say, "Let's just get this over with." It's surprising how long a photo shoot can take.
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