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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

#21

Post by NegatioN »

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…

Wouldn't a complete rewrite of a module usually be a lot easier if the program is procedural?

I think that is one of the big factors stopping that from actually happening with OO code. A rewrite is a lot harder if you tap into what exists elsewhere in the codebase.

I bet you have a lot more insight into this than me though.

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

#22

Post by DigitalJack »

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…

There is another aspect. Changing languages. Rewriting in a language that is sufficiently different from the original forces you to look at the problem with new eyes. You effectively have greater mental coverage of the problem domain.

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

#23

Post by arianvanp »

baldfat wrote: post #18
chowells wrote: post #5

Earlier quoted context omitted.

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…

Cabal made me never use Haskell every again. I work in two different locations and at home. All three locations never worked the same and all had different issues with Cabal. After hours and hours of trying different things I walked away into the wonderland of Racket.

They're working really hard on improving it though . Cabal 2.0 will have a nix-style build system, in which multiple verions of the same dependency can be installed globally (so no separate sandbox per project). This will solve most problems of where cabal breaks down. This gives us almost the same usefulness as Stack. However, you will have to make sure that there is actually a feasible build plan, by setting up your version bounds correctly. With stack, other people take care of this for you, and you never touch the version bounds, which is relaxing but also gives you less control.

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

#24

Post by dwc »

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…

There's a lot of truth in that. A few days ago I wrote a comment about rewriting a program from C++ to C and coming in at about 1/4th the code size. However, I didn't mention C or C++ in that comment because the real savings came from reevaluating requirements, lessons learned, refactoring, et al.

Some time back, someone here on HN posted a comment about rewriting a Java app in... Java. Same basic story of large savings, without changing language at all.

Studying the actual effects of language is hard (time/effort/budget beyond constraints), so people don't do it.

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

#25

Post by mightybyte »

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…

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 can say there are pretty significant. For instance, at my last job using Angular we experienced a particular bug in production a couple times. In my current job our frontend is written in Haskell. I don't make definitive statements that often, but in this case I can definitively say that there is a ZERO chance that bug will happen in our codebase. I can say that because the type system guarantees that that class of bug can't possibly happen.

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

#26

Post by sjakobi »

arianvanp wrote: post #23
baldfat wrote: post #18

Earlier quoted context omitted.

Cabal made me never use Haskell every again. I work in two different locations and at home. All three locations never worked the same and all had different issues with Cabal. After hours and hours of trying different things I walked away into the wonderland of Racket.

They're working really hard on improving it though . Cabal 2.0 will have a nix-style build system, in which multiple verions of the same dependency can be installed globally (so no separate sandbox per project). This will solve most problems of where cabal breaks down. This gives us almost the same usefulness as Stack. However, you will have to make sure that there is actually a feasible build plan, by setting up you…

A nice feature of stack that cabal AFAIK will not provide is that it takes care of installing GHC in multiple versions. I think that's very important for newcomers.

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

#27

Post by Eridrus »

mightybyte wrote: post #25
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…

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.

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

#28

Post by fajpunk »

arianvanp wrote: post #20

I'm the author of the post. I'll be happy to answer any of your questions :)

Thanks for the write up! In the beginning you mention that you ran into some bugs in the Python version that would have been caught by the Haskell type checker. Can you go into more detail about what those bugs were?

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

#29

Post by z3t4 »

DigitalJack wrote: post #22
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…

There is another aspect. Changing languages. Rewriting in a language that is sufficiently different from the original forces you to look at the problem with new eyes. You effectively have greater mental coverage of the problem domain.

Articles like: We switched from language X to language Y with the conclusion that language Y is better smile

My favorite is when they make another post half a year later saying they changed from Y to Z.

It seems that following the trend and using the latest and greatest tools doesn't necessary mean the new tools are better, but that you got to rewrite your applications from scratch, with much more knowledge about the problem domain then before.

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

#30

Post by tazjin »

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…

I am a "domain expert" and that is why I use stack for Haskell projects. It's much preferable to let somebody else handle the burden of ensuring that certain dependencies are compatible with each other.

> Stack is a mysterious "solution" to a problem

There's nothing mysterious about stack. It's just a group of people who step up and say "I am responsible for package $x" and then work together to find stable sets of versions that are guaranteed to work together.

The whole process happens out in the open, for example here is an issue tracking a compatibility breaking change in a common HTML library: https://github.com/fpco/stackage/issues/2246

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