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Default module header `module Main where`
by Joachim Breitner 24 May '17

24 May '17

Hi, a very small proposal to be considered for Haskell': Currently, the report states An abbreviated form of module, consisting only of the module body, is permitted. If this is used, the header is assumed to be ‘module Main(main) where’. I propose to change that to An abbreviated form of module, consisting only of the module body, is permitted. If this is used, the header is assumed to be ‘module Main where’. The rationale is that a main-less main module is still useful, e.g. when you are working a lot in GHCi, and offload a few extensions to a separate file. Currently, tools like hdevtools will complain about a missing main function when editing such a file. It would also work better with GHC’s -main-is flag, and avoid problems like the one described in https://ghc.haskell.org/trac/ghc/ticket/13704 I don’t see any downsides. When compiling to a binary, implementations are still able to detect that a Main module is not imported by any other module and only the main function is used, and optimize as if only main were exported. Greetings, Joachim -- Joachim “nomeata” Breitner mail(a)joachim-breitner.de • https://www.joachim-breitner.de/ XMPP: nomeata(a)joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F Debian Developer: nomeata(a)debian.org

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Haskell 2020: 'let' to be optional and with wider scope of visibility, like other Haskell functions
by Vassil Ognyanov Keremidchiev 18 Apr '17

18 Apr '17

Hello! A small proposition for the next standard. 1) It is to lower verbosity with omitting 'let' keyword in do-notation and use only (=) for describing let/pure blocks. Example: currently: main = do let x = expression1... let y = expression2... z <- action1 putStrLn (x ++ y ++ z) It could be made less verbose currently with putting x and y in the same 'let' block: main = do let x = expression1... y = expression2... z <- action1 putStrLn (x ++ y ++ z) But what if we use (=) for describing different expressions in do-block. main = do x = expression1... y = expression2... z <- action1 putStrLn (x ++ y ++ z) So pure 'let' expressions to use (=) for assignment and monadic actions use (<-) for execution/chaining. If 'let' is optional - this proposition will be backward compatible. 2) Second proposition is every pure expression ('let') in do-block to have visibility in whole block, just like top-level function is visible in whole module. Currently there is difference in visibility depending on that if a function is in do-block or is outside it. Example: main = do z <- action x x = expression1 y y = expression2 putStrLn (x ++ y ++ z) Best regards, Vassil Keremidchiev

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Re: Multiple imports on a single line
by Doug McIlroy 02 Feb '17

02 Feb '17

> I often see a confusion between greater expresiveness (good goal) and > having to type less (largely irrelevant goal). By all means make the module > system more expressive, but try to avoid "clever" things for convenience. To expand upon this principle a bit, syntactic sugar that promises to save O(1) typing in an n-line module is suspect; that which might save O(n) is more promising. Doug

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Multiple imports on a single line
by Vassil Ognyanov Keremidchiev 02 Feb '17

02 Feb '17

Hello! What do you think about an idea to have multiple imports on a single line, like: module MyApp where import Data.Text, Data.Foldable, Control.Concurrent ... That way we could write more concise and short code as Haskell promises. This will be useful for small programs like scripts, small tools, tutorials, examples, etc. Best regards, Vassil Keremidchiev

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Named arguments to functions?
by Saurabh Nanda 13 Nov '16

13 Nov '16

Hi Everyone, I was going through https://prime.haskell.org/wiki/Process#Proposals and noticed the following: > Ideally the language change should be implemented already, so that experience gained with the implementation can inform the discussion Is this a hard requirement? I would like to see the ability to pass named arguments to functions somehow (most probably through anonymous records). I'm unaware of any existing language extension that solves this problem. Does this render the discussion out-of-bounds from a Haskell Prime perspective? Has this already been proposed and considered? Also, going by what is given on the Wiki, I'm confused about where to check the current status of proposals that are being considered. Which is the primary link: * https://prime.haskell.org/query?status=new&status=assigned&status=reopened&… * Or, https://github.com/haskell/rfcs -- Saurabh.

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Proposal: Include InstanceSigs
by Joachim Breitner 02 Nov '16

02 Nov '16

Hi, looking at Haskell prime’s trac, I noticed that there is no formal proposal to include InstaceSigs¹ in the next language revision. As a teacher who uses live coding in a text editor, I usually write out all type signatures. Not being able to do that for instance methods is a minor annoyance. So I guess by sending this mail I started the proposal process properly? Greetings, Joachim ¹ https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_ext… -- Joachim “nomeata” Breitner mail(a)joachim-breitner.de • https://www.joachim-breitner.de/ XMPP: nomeata(a)joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F Debian Developer: nomeata(a)debian.org

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GitHub proposal repo permissions
by Iavor Diatchki 19 Oct '16

19 Oct '16

Hello, I was just trying to update the `Haskel 2020` project as it is not in sync with the actual pull-requests, bit I can't see a way to do it. Am I missing something, or do I simply not have the required permissions? If this is indeed a permissions issue, could someone with access fix it (maybe David?). Probably the easiest would be to create a group with all the members and give it access to the repo. -Iavor

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Process question
by Iavor Diatchki 18 Oct '16

18 Oct '16

Hello, Now that we've started with a few proposal, I am realizing that I have no idea how to proceed from here. In particular: 1. How would I request I proposal to be rejected 2. How would I request that a proposal be accepted Ideas? -Iavor

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Proposal: accept tuple sections
by Iavor Diatchki 13 Oct '16

13 Oct '16

Hello, it seems that there isn't much controversy over the TupleSections propsal, so I'd like to move the we accept it for the next language standard. Does anyone have any objections? -Iavor

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Step-by-step guide for creating a new proposal
by Iavor Diatchki 07 Oct '16

07 Oct '16

Hello, During our Haskell Prime lunch meeting at ICFP, I promised to create a detailed step-by-step guide for creating Haskell Prime proposals on GitHub. The instructions are now available here: https://github.com/yav/rfcs/blob/instructions/step-by-step-instructions.md Please have a look and let me know if something is unclear, or if I misunderstood something about the process. Cheers, -Iavor

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