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>But you make an interesting point in a way. One can ask, ok here are two non-strictly functional languages that seem to be fairly practical. Used for large dis

>But you make an interesting point in a way. One can ask, ok here are two non-strictly functional languages that seem to be fairly practical. Used for large distributed mission critical systems. I think there're at least these problems with Haskell: * The language is badly designed. See the number of extensions which aren't standardized but widely used. See also obvious problems such as requirement to use renames when importing code, and problem with record names conflicts which isn't solved for years. * The focus of the language isn't correct. Lazy evaluations creates a lot of problems both in program performance and complexity of the compiler. The most important parts are pureness and side effect control. * The language is already obsolete. Many its constructions and related complexities are redundant if we unify type and expression level, and get as a result dependently typed system. I hope some language in the future will implement these ideas, and we will have a widely used pure functional dependently typed language with explicit control of effects. I see two candidates for such a language: * Pure script - it's Haskell done right, compiledd to JS. Unfortunately, it doesn't support dependent types. * Idris - it's the language which I describe, but I fear that it's impossible to create a widely used commercial language without major industry players' support.

mightybyte 12y ago
> the number of extensions which aren't standardized but widely used. Actually, I think this is something that Haskell did right. It allows experimentation with new language ideas in a way that allows them to be tested safely with existing codebases. Edward Kmett recently had this to say about it: > I appreciate Haskell's willingness to take a very very long view, and explore the design options, before committing to a path. In many ways, it is this feature of our community and our language that keeps other programming languages looking to us for features and designs to steal. > The language is already obsolete. By that argument so are C, C++, Java, etc. But it's about the existence of a mature ecosystem, not about what is theoretically known. > Pure script PureScript is great, but its compile to JS basis makes it inappropriate as a general purpose language. > Idris Idris looks promising, but it doesn't have a large enough ecosystem yet. I would certainly be willing to switch from Haskell to Idris in the future, but Haskell already is at least a little bit dependently typed [1] and as hinted at above I wouldn't be surprised if Haskell is able to continue improving its dependent typing capability as research advances. [1] https://www.youtube.com/watch?v=OZWYohmLKuU https://www.youtube.com/watch?v=OZWYohmLKuU
- seanwilson 12y ago
  Given that not even basic functional programming has become popular yet, I can't see dependent types being widely adopted for decades. The learning curve for using dependent types is incredibly steep and capturing interesting properties in types inevitably requires you to understand and write tricky maths proofs.
  - solomatov 12y ago
    >Given that not even basic functional programming has become popular yet. It's already popular. All the mainstream programming languages already support it.
    - seanwilson 12y ago
      Which languages would you say this was true for? I wouldn't say that was the case until there is wide support for algebraic data types, type inference, pattern matching and immutable data. I see more languages allowing functions as parameters, basic type inference and encouraging immutable data, but they're still missing out on a lot of benefits offered by functional languages like Haskell and OCaml by ignoring these features. I do see functional programming features making their way in to imperative languages but most people are still coding in an imperative way. Mutable data is still the default rather than immutable data for example.
      - watmough 12y ago
        Linq in C#.
- jaggederest 12y ago
  > PureScript is great, but its compile to JS basis makes it inappropriate as a general purpose language. Except that Javascript is rapidly making inroads on everything except systems programming. If Java is a general purpose language (can't be used for systems without translation due to the JVM), then so is anything-which-compiles-to-JS. I think the really important thing is that, while I've been enthusiastic and interested in Haskell for a long time now (~8 years?), the vast majority of people will never understand even a comparatively simple concept like monads, let alone anything higher level than that. Until you can 'get work done' without the equivalent of graduate-level math classes, there's simply no way to develop that 'mature ecosystem' that everyone is hoping for. People have been using 'better if you understand the complication' languages for a long time now, and there's a good reason they're still niche, unfortunately. Erlang is a great language, but it's very definitely not of the same scale of difficulty to understand as Haskell. You can noodle around with Erlang and end up with something that works reasonably well - in my experience with Haskell, if you can't mathematically formalize what you're talking about, you're going to have a bad time, unless you do go the 'embedded scheme interpreter' route, which is a fun project, but why not just use Racket to begin with?
sclv 12y ago
This is a terrible and also hilarious argument. Instead of saying Haskell has too many newfangled ideas, you're instead arguing that it has an insufficient amount of them. So Haskell has newfangled innovations compared to the big players, and it _also_ has a mature ecosystem in widespread use. This puts it ahead of Purescript and Idris for adoption in large scale projects (although I would readily agree that both those languages are pretty great too). I maintain that lazy evaluation works great, it just requires optimizing along different paths than devs are used to -- but it doesn't incur more "overhead" to optimize code than is the case in typical strict languages, which _also_ have to pay that cost, just in different sorts of optimization and reasoning.

mightybyte 12y ago

> the number of extensions which aren't standardized but widely used. Actually, I think this is something that Haskell did right. It allows experimentation with new language ideas in a way that allows them to be tested safely with existing codebases. Edward Kmett recently had this to say about it: > I appreciate Haskell's willingness to take a very very long view, and explore the design options, before committing to a path. In many ways, it is this feature of our community and our language that keeps other programming languages looking to us for features and designs to steal. > The language is already obsolete. By that argument so are C, C++, Java, etc. But it's about the existence of a mature ecosystem, not about what is theoretically known. > Pure script PureScript is great, but its compile to JS basis makes it inappropriate as a general purpose language. > Idris Idris looks promising, but it doesn't have a large enough ecosystem yet. I would certainly be willing to switch from Haskell to Idris in the future, but Haskell already is at least a little bit dependently typed [1] and as hinted at above I wouldn't be surprised if Haskell is able to continue improving its dependent typing capability as research advances. [1] https://www.youtube.com/watch?v=OZWYohmLKuU https://www.youtube.com/watch?v=OZWYohmLKuU

seanwilson 12y ago
Given that not even basic functional programming has become popular yet, I can't see dependent types being widely adopted for decades. The learning curve for using dependent types is incredibly steep and capturing interesting properties in types inevitably requires you to understand and write tricky maths proofs.
- solomatov 12y ago
  >Given that not even basic functional programming has become popular yet. It's already popular. All the mainstream programming languages already support it.
  - seanwilson 12y ago
    Which languages would you say this was true for? I wouldn't say that was the case until there is wide support for algebraic data types, type inference, pattern matching and immutable data. I see more languages allowing functions as parameters, basic type inference and encouraging immutable data, but they're still missing out on a lot of benefits offered by functional languages like Haskell and OCaml by ignoring these features. I do see functional programming features making their way in to imperative languages but most people are still coding in an imperative way. Mutable data is still the default rather than immutable data for example.
    - watmough 12y ago
      Linq in C#.
jaggederest 12y ago
> PureScript is great, but its compile to JS basis makes it inappropriate as a general purpose language. Except that Javascript is rapidly making inroads on everything except systems programming. If Java is a general purpose language (can't be used for systems without translation due to the JVM), then so is anything-which-compiles-to-JS. I think the really important thing is that, while I've been enthusiastic and interested in Haskell for a long time now (~8 years?), the vast majority of people will never understand even a comparatively simple concept like monads, let alone anything higher level than that. Until you can 'get work done' without the equivalent of graduate-level math classes, there's simply no way to develop that 'mature ecosystem' that everyone is hoping for. People have been using 'better if you understand the complication' languages for a long time now, and there's a good reason they're still niche, unfortunately. Erlang is a great language, but it's very definitely not of the same scale of difficulty to understand as Haskell. You can noodle around with Erlang and end up with something that works reasonably well - in my experience with Haskell, if you can't mathematically formalize what you're talking about, you're going to have a bad time, unless you do go the 'embedded scheme interpreter' route, which is a fun project, but why not just use Racket to begin with?

sclv 12y ago

This is a terrible and also hilarious argument. Instead of saying Haskell has too many newfangled ideas, you're instead arguing that it has an insufficient amount of them. So Haskell has newfangled innovations compared to the big players, and it _also_ has a mature ecosystem in widespread use. This puts it ahead of Purescript and Idris for adoption in large scale projects (although I would readily agree that both those languages are pretty great too). I maintain that lazy evaluation works great, it just requires optimizing along different paths than devs are used to -- but it doesn't incur more "overhead" to optimize code than is the case in typical strict languages, which _also_ have to pay that cost, just in different sorts of optimization and reasoning.