The Evolution of a Haskell Programmer (2001)(pages.cpsc.ucalgary.ca)

144 pointsby agomez3142 tahun yang lalu45 comments

pages.cpsc.ucalgary.ca

The Evolution of a Haskell Programmer (2001)

https://pages.cpsc.ucalgary.ca/~robin/class/449/Evolution.htm

50 comments

tromp2 tahun yang lalu

Church Numeral oriented Haskell Programmer:

    three = \f x -> f (f (f x))
    fac = \n f -> n (\f n -> n (f (\f x -> n f (f x)))) (\x -> f) (\x -> x)
    main = print $ fac three (+ 1) 0

GuB-422 tahun yang lalu

As a C programmer, I think it is missing something like

  -- works for all 32-bit integers
  fac n = [1,1,2,6,24,120,720,5040,40320,362880,3628800,39916800,479001600]!!n

tromp2 tahun yang lalu

It does have the non-truncated equivalent "Memoizing Haskell programmer"'s

fac n = (scanl (*) 1 [1..]) !! n

VMG2 tahun yang lalu

https://archive.is/CbAXN for those that get a cert error

Vosporos2 tahun yang lalu

"fac n = product [1..n]" is still something I use at times. It's a beautiful line of code.

quchen2 tahun yang lalu

Plus it fuses the list creation and consumption, there is no list in the compiled program.

ykonstant2 tahun yang lalu

I have a similar list of FizzBuzzes in Lean from when I started programming in that language:

https://drive.google.com/file/d/1lPnQiik5cAx0X2E3GNbw_Oaug87...

I wrote more, but it got too silly.

[deleted]2 tahun yang lalu

osclarto2 tahun yang lalu

I'm glad I don't work with any post-doc Haskell programmers

vrnvu2 tahun yang lalu

They don't _work_ either :P

fuzztester2 tahun yang lalu

They do work.

They post docs.

quickthrower22 tahun yang lalu

There is a Y Combinator in there!

jayceedenton2 tahun yang lalu

My first thought was, "Needs more monads".

Sure enough, in the commentary:

> Monads are woefully un-represented here; I would be grateful if someone could contribute a few (progressive) examples in the spirit of the development above.

[deleted]2 tahun yang lalu

jayceedenton2 tahun yang lalu

> fac n = product [1..n]

This is a beautiful line of code.

In all seriousness, I'd probably prefer to find the Junior or "Another junior" version if I was browsing a project.

tankfeeder2 tahun yang lalu

Evolution of Picolisp coder. [https://git.envs.net/mpech/tankf33der/raw/branch/master/vers...]

7thaccount2 tahun yang lalu

How often do you code in pico lisp? I think it's a neat project, but haven't really found a use yet.

Tabular-Iceberg2 tahun yang lalu

The invalid certificate and the oddball text encoding is illustrative of the Haskell programmer's inability to cope with practical computing problems.

kccqzy2 tahun yang lalu

The article predates the popularity of UTF-8 encoding on the World Wide Web.

lukan2 tahun yang lalu

It is from 2001. And maybe not maintained anymore. Probably also a possible explanation.

Tabular-Iceberg2 tahun yang lalu

The meme that Haskellers never accomplish anything practical is probably even older, maybe as old as the language itself.

pyrale2 tahun yang lalu

The point is that encoding was not a problem just for ivory tower practicians back then. Python is an exemple of definitely-not-an-ivory-tower language that struggled with the same issues.

Also the practical joke is largely independant from haskell. It's pretty much an example of shuhari principles applied.

lynx232 tahun yang lalu

The meme likely comes from a time when monads (and therefore IO) were not invented yet.

bazoom422 tahun yang lalu

Yeah, after monads were invented Haskell have conquered the world through its reputation as a practical “get things done” language.

Symmetry2 tahun yang lalu

As "A Brief, Incomplete, and Mostly Wrong History of Programming Languages" put it:

1990 - A committee formed by Simon Peyton-Jones, Paul Hudak, Philip Wadler, Ashton Kutcher, and People for the Ethical Treatment of Animals creates Haskell, a pure, non-strict, functional language. Haskell gets some resistance due to the complexity of using monads to control side effects. Wadler tries to appease critics by explaining that "a monad is a monoid in the category of endofunctors, what's the problem?"

https://james-iry.blogspot.com/2009/05/brief-incomplete-and-...

the_af2 tahun yang lalu

It's a funny joke (I love that post), but it's mostly for people looking from outside in. It says nothing about actually doing IO with Haskell using monads, which is practical and done, and not particularly difficult.

We shouldn't mistake memes for actual insight.

bazoom422 tahun yang lalu

Yeah as long as you understand how to use monads IO is easy.

This is why Haskell tutorials tend to have 100 pages of dense type-theory before getting to “hello world”, while other languages have that on the first page.

tome2 tahun yang lalu

I'm not sure which tutorials you're thinking of. Not this one I guess

https://wiki.haskell.org/Haskell_in_5_steps#Write_your_first...

or this one

https://riptutorial.com/haskell/example/898/hello--world-

Can you link to the one that has 100 pages before getting to “hello world”?

bazoom422 tahun yang lalu

Learn you a Haskell gets to Hello World at page 128.

tome2 tahun yang lalu

Yeah, but that's not because the first 127 pages are "dense type theory". It's because that's the first time it teaches about compiled programs rather than the REPL. Besides, "Hello world" also appears on page 14.

https://learnyouahaskell.com/learnyouahaskell.pdf

the_af2 tahun yang lalu

This is simply untrue. You can do IO without understanding what a monad is, simply taking it as "there is this keyword and this syntax I need to use".

No Haskell tutorials that I know of take long to reach "hello world", which is in fact a shorter program in Haskell than in some mainstream programming languages.

tempodox2 tahun yang lalu

> and not particularly difficult.

Wait until you want debug output in a deeply nested function that isn't already in the IO monad.

jaspervdj2 tahun yang lalu

You can use trace for that which is part of the base library:

https://hackage.haskell.org/package/base-4.19.1.0/docs/Debug...

pyrale2 tahun yang lalu

Unrelated, but many thanks for organizing Zurihac year after year.

the_af2 tahun yang lalu

Debugging output, or just plain debugging, is often difficult regardless of the programming language. I wouldn't say this sets Haskell apart.

7thaccount2 tahun yang lalu

The main language creator himself famously called Haskell "useless". It was tongue in cheek of course.

kqr2 tahun yang lalu

Also with a very specific meaning that often gets lost. It was specifically about Haskell before there was an IO type. Without I/O operations, any language is "useless".

(Further context: in the discussion Haskell is described as starting out useless and carefully approaching useful. Other languages start with the footguns and then retrofit useful limitations from the other end!)

7thaccount2 tahun yang lalu

I thought there was an interview where he said that many years after Haskell had I/O. I believe you though as I haven't been enamored with Haskell for a long time. It's a cool language, but just doesn't click with me. I can see why it does for others though.

jasode2 tahun yang lalu

>The invalid certificate [...] is illustrative of the Haskell programmer's inability

Why would one assume the invalid certificate is caused by that particular professor instead of the IT department's staff at the University of Calgary?

boxed2 tahun yang lalu

It's a joke.

[deleted]2 tahun yang lalu

kreetx2 tahun yang lalu

My experience is that this may be illustrative of academic programmers. People working in industry are expected to produce something, regardless of the language. This is why I'd recommend academics to spend a bit of time in the industry, regardless of it feeling awkward/inconvenient, of not being given time to go deep in any specific subject.

pyrale2 tahun yang lalu

> People working in industry are expected to produce something,

Yeah, academics are only interested in producing silly papers to justify expensive trips to exotic conference locations.

Meanwhile, industry produces important and useful stuff like Scrum™ Poker-planning estimates and Jira®-powered burndown charts to track completion of their Confluence© fully-documented user-stories.

kreetx2 tahun yang lalu

Sure, bigger companies have "molded" corners like that, too. But plenty of companies are small, where there there isn't much space in getting nothing practical done.

im3w1l2 tahun yang lalu

And yet big companies somehow pay higher wages. My hunch is that they can afford to pay higher wages because while big-tech employees may spend 7:30 a day on scrum poker or whatever, those last 30 minutes they are actually chipping away at some real problem that bothers 100s of millions of people. Whereas startups employees spend 10 hours a day reinventing "Wheels for Dogs"

Kototama2 tahun yang lalu

Don't forget LEGO® Serious Play®.

pyrale2 tahun yang lalu

Shit, TIL. I can now become a Certified Lego® Serious Play® facilitator [1], with a certificate delivered by none other than:

> The Authority on Professional LEGO Serious Play.

[1]: https://www.serious.global/

whiterknight2 tahun yang lalu

Both are indeed ridiculous organizations. Best not to find yourself a true believer on either side.

[deleted]2 tahun yang lalu