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How we secretly introduced Haskell and got away with it

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Re: How we secretly introduced Haskell and got away with it

#91

Post by seagreen »

chowells wrote: post #5
sid-kap wrote: post #2

The comparison between Stack and Python build tools is striking: > No messing around with virtualenvs and requirement files. Everybody builds with the same dependency versions. No more “works on my machine” and “did you install the latest requirements?”. I wonder why the Python ecosystem, which is much more mature, doesn't provide a build tool as delightful as Stack (which is less than 2 years old).

Probably for the same reason I greatly prefer cabal to stack. Stack assumes it knows better than me. Cabal just does what I tell it to do. As a domain expert, I greatly prefer the latter. It does what I want, nothing more, nothing less. Stack is a mysterious "solution" to a problem I don't have that works by doing everything differently than I do. Stack was created because not everyone is a domain expert. A lot of pe…

Consider this situation: three different developers are working on the same application. They should all have the exact same dependencies installed, right? Therefore they should be working of of a freeze file of some kind.

Why use an entirely ad-hoc freeze file when you can start from a known-working snapshot (that some of them might already have installed on their machines!) and modify it from there. I find this the perfect option in this kind of situation, and so object to saying that stack is just for non-experts.

Re: How we secretly introduced Haskell and got away with it

#93

Post by js8 »

mybrid wrote: post #6

In the 1990s I did research on the efficacy claims of object oriented programming versus procedural programming. This article bares a striking resemblance in the claims. Case study after case study showed that object oriented code had less bugs due to compilers catching bugs, etc. However, almost every study was similar to this report: it was a re-write from procedural to object-oriented. There exists strong evidence…

So what was the result of your research? I am no fan of OOP style, but I believe it has advantages over procedural style, and I also believe that functional style has advantages over OOP style.

Re: How we secretly introduced Haskell and got away with it

#94

Post by seagreen »

mybrid wrote: post #6

In the 1990s I did research on the efficacy claims of object oriented programming versus procedural programming. This article bares a striking resemblance in the claims. Case study after case study showed that object oriented code had less bugs due to compilers catching bugs, etc. However, almost every study was similar to this report: it was a re-write from procedural to object-oriented. There exists strong evidence…

Absolutely! Thanks for standing up for rigor here.

(The actual argument for functional programming is its adoption by elite programmers like Standard Chartered's Strats team, Facebook's anti-spam group, and Jane Street as a whole.)

Re: How we secretly introduced Haskell and got away with it

#96

Post by runeks »

chrisdone wrote: post #34
sid-kap wrote: post #2

The comparison between Stack and Python build tools is striking: > No messing around with virtualenvs and requirement files. Everybody builds with the same dependency versions. No more “works on my machine” and “did you install the latest requirements?”. I wonder why the Python ecosystem, which is much more mature, doesn't provide a build tool as delightful as Stack (which is less than 2 years old).

Stack requires package sets (aka "snapshots"), which some kind of CI system (Stackage: http://stackage.org/ ) has to do a daily build job to see if they all build and pass tests together. That requires some money to keep running, and buy-in from package authors as there is a maintenance overhead each release. It took a few years for Stackage to get enough packages in it to be generally useful, and then we wrote the S…

Stack enables application development in Haskell, as opposed to just library development. A proper library doesn't have more than 20-ish dependencies, in my opinion, and manually handling these and their version bounds is not a problem.

But when writing applications with hundreds of dependencies, manually figuring out a mutually compatible dependency range for all packages just isn't an option. At least not if you want to spend time prototyping code, rather than think about dependency ranges.

hpack solves additional problems with the .cabal format (sane defaults as opposed to build failure), and I highly recommend it, for application development at least. I just discovered it a month ago and now I wouldn't be able to live without it.

Re: How we secretly introduced Haskell and got away with it

#97

Post by pharrington »

Eridrus wrote: post #27
mightybyte wrote: post #25

Earlier quoted context omitted.

That's all well and good except for the fact that your standards are impossible to reach. Even if I do write the exact same project with two different languages, there will always be differences in either the skill of the teams or, if the teams are the same, the amount of experience the team has when they tackle the project. What we can do is compare similar types of projects in different languages. And the things we…

It seems pretty easy to control for this, just write the functional version first, and if it is as big free your results obviously sidestep this criticism.

I'm not sure what you're getting at. He's saying Haskell's type safety makes impossible the bug that was in his JavaScript project. As far as I can tell, it's impossible to write a type safe system in pure JavaScript.

edit: To clarify this thought a bit, obviously you can transpile code in a type safe language to JavaScript. At the abstraction level of the code written, the project is type safe. The generated JavaScript itself is not; however this isn't a problem if the transpiler is correct. The same principle applies to Haskell compiling to non-typesafe machine code.

Re: How we secretly introduced Haskell and got away with it

#98

Post by seagreen »

vkou wrote: post #32
chongli wrote: post #12

Earlier quoted context omitted.

I wonder why the Python ecosystem, which is much more mature I hope I'm not being too pedantic but Python's ecosystem is much larger than Haskell's, it isn't really more mature . Haskell and Python are very similar in age as languages go.

Maturity comes from: * Millions of person-hours being poured into a language... * ...Over a long enough time period that the language can go through several develop-eval-improve cycles - that take real world use cases (And not one-liner bubble sort implementations) into account. In this sense, it doesn't matter whether or not Haskell was invented in 1890, or 1990. #2 is required for maturity, but so is #1. (I am not…

Absolutely. In fact, one of big things holding back Haskell has been the immaturity of its libraries (because for a long time they were built by hobbyist and academics, with little industry support, in a language where lots of things were new and old architectures didn't work well). Happily that's now mostly behind us: https://github.com/Gabriel439/post-rfc/blob/master/sotu.md (editor support being the main exception)

Re: How we secretly introduced Haskell and got away with it

#99

Post by kisstheblade »

Always when I see haskell demonstrations eveyrthing looks like just interface declarations.

You can do beautiful interfaces with eg. java also. But where is the meat where anything actually happens? I rarely see that in these posts. Yes I could look up the source but I don't have time to read through it randomly.

This looks just so nice and stuff just magically works?:

runWorkerLoop :: (MonadBackingStore m, MonadLogger m, MonadIO m) => WorkerState -> m WorkerState

And monads to boot! (are monads haskells equivalent of java factories? I kid, I kid :)

Re: How we secretly introduced Haskell and got away with it

#100

Post by lima »

Lev1a wrote: post #10
nimish wrote: post #9

Earlier quoted context omitted.

I have pygradle generate a PEX file for all of my command scripts. Not as seamless as cargo or stack, but it works without rewriting everything.

I should probably have clarified that I wanted the "seamless" way of making the final executable. IIRC, I tried(really hard) and failed on getting some method of "freezing" for Python to work, which made me weary of the prospect of trying something like that in Python in the future(now past).

pyinstaller works great. No issues whatsoever and I'm happily deploying Python 3.6 to machines as far back as RHEL 5.

Single binary to deploy, no dependencies except libc, life is great.

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