6 ms·

Can you explain what Haskell fall behind in term of writing web servers? As someone who wrote Node and Haskell web apps in the past I don't think it's true. Le

Can you explain what Haskell fall behind in term of writing web servers? As someone who wrote Node and Haskell web apps in the past I don't think it's true. Let't take a look at one of premier Haskell web framework Yesod. It has support for authentication, http/2, https, middlewares, logging, etc. I don't think there is any "modern web protocols" that Haskell cannot support. It's only a language anyway. It popular and powerful enough for people to implement something novel with it. I know Haskell had been used for testing-bed for programming language ideas because making abstractions in Haskell is freaking easy. But you can just ignore them and stick to boring, working and practical subset of the language. The language already been heavily used in industries so I know for a fact that it's fit for production use. I myself did deploy Haskell apps to production (Telegram bot for personal use) and never encounter any problem.

Silhouette 6y ago
Let't take a look at one of premier Haskell web framework Yesod. OK, let's do that, since that's exactly one of the things I tried. So, one thing I was interested in was indeed support for HTTP/2. You've just stated that Yesod supports it. Right now, with the aid of all of the main types of documentation linked from the Yesod site and a search engine, I am totally unable to verify that. I literally cannot find a single reference to it on the entire Web. The same is true of identifying anything about the level of TLS support, configuring which cipher suites to accept, etc. I was also interested in WebSocket support. Again, there's no obvious sign of this in the documentation, at least not that I found in a few minutes of browsing. Any of it. Seriously, projects wanting programmers to use them should have one authoritative source of reference documentation, and it should be up to date and easily searchable. Still, on this one, at least a web search finds me yesod-websockets. That has the usual mix of package technicalities on its Hackage page, plus a documentation page with a long list of functions, type signatures and one-line descriptions in the Hackage documentation. Ironically, there is also a link from the package description to Stackage, which has another page of package technicalities linking to another similar page of documentation, which is roughly the same, but apparently the two versions I've found are different because one is 0.3.0.1 and one is 0.3.0.2. There's nothing to give you confidence in using a library in production like a four-part version number that starts with "0.". And no obvious description of the real level of maturity and stability that reflects, so I'm going to assume this is pre-release quality. And did I mention there should be one authoritative home for reference documentation? That goes for the package itself, too. No matter how many times a Haskell fan says that this kind of thing is sufficient, it simply isn't. There is no introductory tutorial. There are no illustrative code snippets or HOWTOs or full working examples. There is no apparent organisation of any kind in what little reference documentation does exist except for a few headers that have little meaning if you don't already know what they mean. I have no idea how stable this package and its API are, but the version numbers (plural) suggest the default assumption should be "not very". This isn't a serious proposition for production work. It just isn't. Maybe it's useful if you already know the Yesod library and the related libraries well, for example because you developed some of that ecosystem, or you've talked with someone who did, or maybe you've watched it evolve since it was simple enough to figure out from the limited documentation and kept up. But for someone with Haskell experience who hasn't used it to build a web server before, it's all but useless. For the record, I had a working server, including proof of concept WebSockets code, up and running on both the client and server side using Node, in less time than it's taken me to re-check a few facts and then write this comment. And a web search for any of "node http2", "node tls" or "node websocket" immediately locates a wealth of relevant documentation, examples, etc.
- ghostwriter 6y ago
  > Right now, with the aid of all of the main types of documentation linked from the Yesod site and a search engine, I am totally unable to verify that. I literally cannot find a single reference to it on the entire Web. > The same is true of identifying anything about the level of TLS support, configuring which cipher suites to accept, etc. This is really weird, and I think that your comment doesn't represent the reality. Here's the official Yesod Book[1] mentioning WAI and Warp as a de-facto standard server implementation for a Haskell Web ecosystem. The Hackage page for Warp[2] contains "HTTP/2" and "TLS" at the very top of the package description section. Googling "haskell warp tls" produces the topmost link pointing to warp-tls package[3]. The package docs clearly show all supported ciphers[4]. And googling "haskell yesod http2" produces the second top link[5][6] that mentions HTTP/2 and TLS and it has been around since 2015. [1]: https://www.yesodweb.com/book/web-application-interface#web-application-interface_hello_world https://www.yesodweb.com/book/web-application-interface#web-... [2]: https://hackage.haskell.org/package/warp https://hackage.haskell.org/package/warp [3]: https://hackage.haskell.org/package/warp-tls https://hackage.haskell.org/package/warp-tls [4]: https://hackage.haskell.org/package/warp-tls-3.2.12/docs/Network-Wai-Handler-WarpTLS.html#v:tlsCiphers https://hackage.haskell.org/package/warp-tls-3.2.12/docs/Net... [5]: https://www.yesodweb.com/blog/2015/07/http2 https://www.yesodweb.com/blog/2015/07/http2 [6]: https://pasteboard.co/JaRXKUR.png https://pasteboard.co/JaRXKUR.png
  - Silhouette 6y ago
    Here's the official Yesod Book[1] mentioning WAI and Warp as a de-facto standard server implementation for a Haskell Web ecosystem. So just to be clear: To discover what is actually possible in this area, someone new to Yesod is supposed to read the entire book through to an appendix, which itself could kindly be described as "not entirely clear". Then they're supposed to recognise that they need to write their Haskell application using WAI and a Warp backend (whatever that means in this context, because the relationships between these tools are among the "not entirely clear" aspects of that appendix) instead of using the other tools that were already described earlier in the book, despite having no obvious motivation for doing so at this point (because terms like HTTP/2 and TLS do not appear anywhere in the Yesod book appendix you linked to). Then on the off chance that these alternative tools mentioned in an appendix of an online book can do what the developer wants even though the appendix doesn't say anything about that at all, our intrepid developer is supposed to go and look up the Hackage pages for those tools, one of which does at least mention the term HTTP/2. There's no further information on those documentation pages about how to actually use important features of HTTP/2, for example setting up server push, though. In fact, the only reference to server push I can find anywhere in the Warp documentation relates to the function setServerPushLogger. So while I appreciate your taking the time to comment, I'm afraid my previous conclusion has not changed. Maybe these tools are useful if you already understand them in detail, but for someone familiar with Haskell but writing a web application with it for the first time, this experience isn't even on the same scale as a good, production-ready ecosystem. Finally, just for the record, while choosing the perfect query to Google might have found you a useful link, several similar obvious searches I tried before did not, nor indeed does the exact term you mentioned ("haskell yesod http2") in some other search engines such as Duck Duck Go. And your Pasteboard link (I assume) intending to demonstrate the search you managed successfully is not working from here.

Silhouette 6y ago

Let't take a look at one of premier Haskell web framework Yesod. OK, let's do that, since that's exactly one of the things I tried. So, one thing I was interested in was indeed support for HTTP/2. You've just stated that Yesod supports it. Right now, with the aid of all of the main types of documentation linked from the Yesod site and a search engine, I am totally unable to verify that. I literally cannot find a single reference to it on the entire Web. The same is true of identifying anything about the level of TLS support, configuring which cipher suites to accept, etc. I was also interested in WebSocket support. Again, there's no obvious sign of this in the documentation, at least not that I found in a few minutes of browsing. Any of it. Seriously, projects wanting programmers to use them should have one authoritative source of reference documentation, and it should be up to date and easily searchable. Still, on this one, at least a web search finds me yesod-websockets. That has the usual mix of package technicalities on its Hackage page, plus a documentation page with a long list of functions, type signatures and one-line descriptions in the Hackage documentation. Ironically, there is also a link from the package description to Stackage, which has another page of package technicalities linking to another similar page of documentation, which is roughly the same, but apparently the two versions I've found are different because one is 0.3.0.1 and one is 0.3.0.2. There's nothing to give you confidence in using a library in production like a four-part version number that starts with "0.". And no obvious description of the real level of maturity and stability that reflects, so I'm going to assume this is pre-release quality. And did I mention there should be one authoritative home for reference documentation? That goes for the package itself, too. No matter how many times a Haskell fan says that this kind of thing is sufficient, it simply isn't. There is no introductory tutorial. There are no illustrative code snippets or HOWTOs or full working examples. There is no apparent organisation of any kind in what little reference documentation does exist except for a few headers that have little meaning if you don't already know what they mean. I have no idea how stable this package and its API are, but the version numbers (plural) suggest the default assumption should be "not very". This isn't a serious proposition for production work. It just isn't. Maybe it's useful if you already know the Yesod library and the related libraries well, for example because you developed some of that ecosystem, or you've talked with someone who did, or maybe you've watched it evolve since it was simple enough to figure out from the limited documentation and kept up. But for someone with Haskell experience who hasn't used it to build a web server before, it's all but useless. For the record, I had a working server, including proof of concept WebSockets code, up and running on both the client and server side using Node, in less time than it's taken me to re-check a few facts and then write this comment. And a web search for any of "node http2", "node tls" or "node websocket" immediately locates a wealth of relevant documentation, examples, etc.

ghostwriter 6y ago
> Right now, with the aid of all of the main types of documentation linked from the Yesod site and a search engine, I am totally unable to verify that. I literally cannot find a single reference to it on the entire Web. > The same is true of identifying anything about the level of TLS support, configuring which cipher suites to accept, etc. This is really weird, and I think that your comment doesn't represent the reality. Here's the official Yesod Book[1] mentioning WAI and Warp as a de-facto standard server implementation for a Haskell Web ecosystem. The Hackage page for Warp[2] contains "HTTP/2" and "TLS" at the very top of the package description section. Googling "haskell warp tls" produces the topmost link pointing to warp-tls package[3]. The package docs clearly show all supported ciphers[4]. And googling "haskell yesod http2" produces the second top link[5][6] that mentions HTTP/2 and TLS and it has been around since 2015. [1]: https://www.yesodweb.com/book/web-application-interface#web-application-interface_hello_world https://www.yesodweb.com/book/web-application-interface#web-... [2]: https://hackage.haskell.org/package/warp https://hackage.haskell.org/package/warp [3]: https://hackage.haskell.org/package/warp-tls https://hackage.haskell.org/package/warp-tls [4]: https://hackage.haskell.org/package/warp-tls-3.2.12/docs/Network-Wai-Handler-WarpTLS.html#v:tlsCiphers https://hackage.haskell.org/package/warp-tls-3.2.12/docs/Net... [5]: https://www.yesodweb.com/blog/2015/07/http2 https://www.yesodweb.com/blog/2015/07/http2 [6]: https://pasteboard.co/JaRXKUR.png https://pasteboard.co/JaRXKUR.png
- Silhouette 6y ago
  Here's the official Yesod Book[1] mentioning WAI and Warp as a de-facto standard server implementation for a Haskell Web ecosystem. So just to be clear: To discover what is actually possible in this area, someone new to Yesod is supposed to read the entire book through to an appendix, which itself could kindly be described as "not entirely clear". Then they're supposed to recognise that they need to write their Haskell application using WAI and a Warp backend (whatever that means in this context, because the relationships between these tools are among the "not entirely clear" aspects of that appendix) instead of using the other tools that were already described earlier in the book, despite having no obvious motivation for doing so at this point (because terms like HTTP/2 and TLS do not appear anywhere in the Yesod book appendix you linked to). Then on the off chance that these alternative tools mentioned in an appendix of an online book can do what the developer wants even though the appendix doesn't say anything about that at all, our intrepid developer is supposed to go and look up the Hackage pages for those tools, one of which does at least mention the term HTTP/2. There's no further information on those documentation pages about how to actually use important features of HTTP/2, for example setting up server push, though. In fact, the only reference to server push I can find anywhere in the Warp documentation relates to the function setServerPushLogger. So while I appreciate your taking the time to comment, I'm afraid my previous conclusion has not changed. Maybe these tools are useful if you already understand them in detail, but for someone familiar with Haskell but writing a web application with it for the first time, this experience isn't even on the same scale as a good, production-ready ecosystem. Finally, just for the record, while choosing the perfect query to Google might have found you a useful link, several similar obvious searches I tried before did not, nor indeed does the exact term you mentioned ("haskell yesod http2") in some other search engines such as Duck Duck Go. And your Pasteboard link (I assume) intending to demonstrate the search you managed successfully is not working from here.