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I tried Haskell for 5 years

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Re: I tried Haskell for 5 years

#241

Post by user5994461 »

eximius wrote: post #234
zzalpha wrote: post #106

Earlier quoted context omitted.

but it's not that different than what you'd get with other programming languages. Until you have to solve a (maddeningly common) space leak issue. That's a problem unique to lazily evaluated languages (basically Haskell) and is godawful to debug. It reminds me of solving git problems... you suddenly find yourself having to tear back the abstraction layer that is the language and compiler and start thinking about thun…

I find this response a little ironic because we don't really see complaints about knowing the C runtime and C compiler when performance becomes a problem, which is also jarring and frustrating. But, ultimately, sometimes languages have failings and we need to peek under the hood to figure out how to address it - we're just more comfortable with the relatively common and direct mapping of the C runtime. I am not exper…

The C is very straightforward.

Maybe you meant C++? You see no complaint because noone use that anymore. Anything that can be done with an easier language is done with an easier language. The hardcore C++ performance critical code is left to a few veterans, who don't complain.

Re: I tried Haskell for 5 years

#242

Post by Veedrac »

eximius wrote: post #234
zzalpha wrote: post #106

Earlier quoted context omitted.

but it's not that different than what you'd get with other programming languages. Until you have to solve a (maddeningly common) space leak issue. That's a problem unique to lazily evaluated languages (basically Haskell) and is godawful to debug. It reminds me of solving git problems... you suddenly find yourself having to tear back the abstraction layer that is the language and compiler and start thinking about thun…

I find this response a little ironic because we don't really see complaints about knowing the C runtime and C compiler when performance becomes a problem, which is also jarring and frustrating. But, ultimately, sometimes languages have failings and we need to peek under the hood to figure out how to address it - we're just more comfortable with the relatively common and direct mapping of the C runtime. I am not exper…

When have you ever had the C runtime be the cause of a performance problem?

Re: I tried Haskell for 5 years

#243

Post by arnon »

charlieflowers wrote: post #192
arnon wrote: post #82

Earlier quoted context omitted.

Haskell works really well for things revolving around languages. At SQream (www.sqream.com), Haskell is used for CLI, SQL parser, SQL language compiler, SQL optimizations and a variety of tools. We also use Haskell to generate Python code for testing (think: describing a testing scenario and sets of queries, translating into a runnable, predictable Python script that's easy to debug)

To me, this is Haskell's most appealing strength. The idea is, you can express your domain and logic in Haskell in pure functions which are highly testable, and then you can use that to generate code in any language you want. And the code you generate can have whatever zero-cost abstractions you choose to invent, all implemented in the nice, functional Haskell layer. Haskell's strength at expressing and transforming…

You hit the nail on the head.

We also employ QuickCheck rather extensively, which makes testing millions of scenarios really straightforward.

Re: I tried Haskell for 5 years

#244

Post by arnon »

nom wrote: post #197
arnon wrote: post #74

We have a code base of roughly 200,000 lines of Haskell code, dealing with high performance SQL query parsing, compilation and optimizations. I only remember one situation over the past 5 years that we had a performance issue with Haskell, that was solved by using the profiling capabilities of GHC. I disagree that performance is hard to figure out. It could be better, yes - but it's not that different than what you'd…

> but it's not that different than what you'd get with other programming languages Does your list of other programming languages include C/C++/asm? ;)

Incidentally, yes.

Re: I tried Haskell for 5 years

#245

Post by luispedrocoelho »

codygman wrote: post #221
luispedrocoelho wrote: post #100

Earlier quoted context omitted.

(OP here) I do say it's not that big of a deal in the end: it almost always is OK and at the end you optimize the inner loops by looking at profiles; like in any other project. But when using GHC, I have indeed sometimes ran into situations where I expect something to be fast when it is not (e.g., `ByteString.map (+ value)` is incredibly slow compared to a pseudo-C loop). I also did find a bona fides performance bug…

> (e.g., `ByteString.map (+ value)` is incredibly slow compared to a pseudo-C loop). That situation sounds like you needed a ByteString Builder to get comparable performance.

Maybe, but pseudo-C actually worked very well.

I even have some "real C" in my Haskell code to handle some inner loop stuff.

Re: I tried Haskell for 5 years

#246

Post by jimbokun »

mavelikara wrote: post #232
tetrep wrote: post #50

Earlier quoted context omitted.

> The line that if it compiles, it’s probably correct is often true. That is the meat of why Haskell is so great. I've never so reckless refactored code as much as I do in Haskell, I just wait for the compiler to tell me what I missed and go back and fix it up. I'd never do that in C, C++, Java, etc; it'd be suicide. And while that's still not a great fleshed out explanation, it's a great oversimplification of the sy…

> That is the meat of why Haskell is so great. I've never so reckless refactored code as much as I do in Haskell, I just wait for the compiler to tell me what I missed and go back and fix it up. I'd never do that in C, C++, Java, etc; it'd be suicide. I work on Java projects and do big re-factorings using IntelliJ, relying on the compiler. So this is a bit project-dependent. Java chooses two wrong defaults - nullabil…

"Java chooses two wrong defaults - nullability by default, and mutability by default."

Which of course, are two defaults that Haskell chooses correctly (which is maybe what you were implying).

Re: I tried Haskell for 5 years

#247

Post by jimbokun »

hzhou321 wrote: post #133
zzzzzzzza wrote: post #114

Earlier quoted context omitted.

haskell is objectively expressive. (where expressive means amount of logic per character) there are multiple reasons for this, kind've tied together. Whitespace is function application (no parenthesis to keep track of like lisp, or even e.g. c, java, or javascript, when programming in a functional style). Immutability forces you to compartmentalize and compose everything. when everything is a function, function and v…

By objective, you mean succinctness (which can be simply measured by program character counts)? In this regard, APL must be the most objectively expressive language. What if we run deflation over APL? It happens that I measure expressiveness by the amount of the time the author takes to express an idea and/or the amount of the time the reviewer takes to comprehend an idea. That, unfortunately, is very subjective. APL…

What evidence do you have that APL programmers do not express and comprehend ideas in APL programs much faster than programmers using other languages? Similarly for Haskell.

How do you know you're not just a Blub programmer?

http://www.paulgraham.com/avg.html

Re: I tried Haskell for 5 years

#248

Post by dllthomas »

arnon wrote: post #236
dllthomas wrote: post #184

Earlier quoted context omitted.

If you want more generic SQL tooling in Haskell, my project was just recently open sourced ( https://github.com/uber/queryparser ). It currently has support for Vertica, Hive, and Presto; adding support for more dialects isn't complicated. I'm working on cleaning it up for hackage.

Very interesting! Do you do any sort of typechecking in this? FWIW, HsSqlPpp also supports various dialects. In SQream DB we use a custom dialect, while HsSqlPpp is mostly Postgres.

Typechecking of the SQL statements? There was an internal branch where I was experimenting with that, but it didn't get landed before I left, and isn't in the squashed version.

It was relatively simplistic - along the lines of "things tested for equality must share a type". It was also focused on domain-relevant types, not SQL type (/representation).

> FWIW, HsSqlPpp also supports various dialects. In SQream DB we use a custom dialect, while HsSqlPpp is mostly Postgres.

Nice. It'll be interesting to see where our implementation choices differed, and what we can learn from each other :)

Re: I tried Haskell for 5 years

#249

Post by dllthomas »

Maro wrote: post #145

I have tried to use Haskell a number of times in the past ~5 years for small-scale projects and witnessed others try to use it, and most of these projects (actually I think all) have resulted in failure / rewrites in more simple/plain-vanilla languages like Python/Go. I keep thinking Haskell is interesting, but at some point I had to force myself to stop investing time in it because I kept concluding it's not a good…

> - when the spec of the system keeps changing (=the norm in lean/cont.delivery environments), it's cumbersome/not practical to keep updating the types and deal with the cascading effects

Interesting. I find that one of the best parts of Haskell. If I expose the assumptions I've relied on in the types, then when those assumptions break I have tremendous help knowing what code must change to deal with it.

Re: I tried Haskell for 5 years

#250

Post by harry8 »

platz wrote: post #52
gjkood wrote: post #16

Question to the Haskell experts here. Is Haskell more academic in nature or used heavily in Production environments? Is there an application sweet spot/domain (say Artificial Intelligence/Machine Learning, etc) where it shines over using other languages (I am not talking about software/language architectural issues like type systems or such)? I have no experience with Haskell but do use functional languages such as E…

> Is there an application sweet spot/domain State of the Haskell ecosystem: https://github.com/Gabriel439/post-rfc/blob/master/sotu.md The topics are roughly sorted from greatest strengths to greatest weaknesses. Each programming area will also be summarized by a single rating of either: Best in class: the best experience in any language Mature: suitable for most programmers Immature: only acceptable for early-adopte…

The state of the Haskell ecosystem is that it is amazing at encouraging people to write libraries, especially libraries to assist in writing haskell code but amazingly bad at encouraging people to write actual programs, especially actual programs useful for something that isn't writing code.

Take out the programs that are for writing code, ghc, shellcheck, darcs etc. And what are you actually left with? git-annexe, pandoc, xmonad is hledger worth knowing about if you don't care what language it was written in? (Maybe it's amazing, first I've heard of it).

Whenever I bring this up, people find it upsetting. The Haskell community might need to get past both of those things. 1.0 was 27 years ago. So many fabulous programmers have gone down the road for entertainment or enlightenment so where are your damn apps if you're a language that doesn't suck for writing them, no really, where are they?

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