December 2020 - ghc-devs

Help lead Haskell: Executive Director sought for Haskell Foundation
by Richard Eisenberg 07 Dec '20

07 Dec '20

Posting on behalf of the Haskell Foundation Working Group. Please forward widely! -------- The Haskell Foundation is seeking an Executive Director. Please find the job description here: https://haskell.foundation/ <https://haskell.foundation/executive-director>ed-job-description <https://haskell.foundation/ed-job-description/> The Haskell Foundation (HF) is an independent, non-profit organization dedicated to driving Haskell adoption and open-source development. HF seeks a full-time Executive Director (ED) to lead and develop the organization going forward. The ED is responsible for furthering the HF’s mission and vision, ensuring that resources are in place to accomplish its goals. The HF is supported by an active group of volunteers, and the ED will be a key focal point for that community, in addition to hiring support staff. This is a salaried position. Salary will be commensurate with the experience, qualities, and location of the individual, and will also reflect the Foundation’s status as a non-profit organisation funded by donations.

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[ANNOUNCE] Glasgow Haskell Compiler 9.0.1-alpha1 released
by Ben Gamari 06 Dec '20

06 Dec '20

Hello all, The GHC team is very pleased to announce the availability of the first alpha release in the GHC 9.0 series. Source and binary distributions are available at the usual place: https://downloads.haskell.org/ghc/9.0.1-alpha1/ This first alpha comes quite a bit later than expected. However, we have done a significant amount of testing on this pre-release and therefore hope to be able to move forward quickly with a release candidate next week and with a final release in mid-October. GHC 9.0.1 will bring a number of new features: * A first cut of the new LinearTypes language extension [1], allowing use of linear function syntax and linear record fields. * A new bignum library (ghc-bignum), allowing GHC to be more easily used with integer libraries other than GMP. * Improvements in code generation, resulting in considerable performance improvements in some programs. * Improvements in pattern-match checking, allowing more precise detection of redundant cases and reduced compilation time. * Implementation of the "simplified subsumption" proposal [2] simplifying the type system and paving the way for QuickLook impredicativity in GHC 9.2. * Implementation of the QualifiedDo extension [3], allowing more convenient overloading of `do` syntax. * Improvements in compilation time. And many more. See the release notes [4] for a full accounting of the changes in this release. Do note that there are a few things that we expect will change before the final release: * We expect to sort out a notarization workflow for Apple Darwin, allowing our binary distributions to be used on macOS Catalina without hassle. Until this has been sorted out Catalina users can exempt the current macOS binary distribution from the notarization requirement themselves by running `xattr -cr .` on the unpacked tree before running `make install`. * We will likely transition the Alpine binary distribution to be fully statically-linked, providing a convenient, distribution-independent packaging option for Linux users. * We will be merging a robust solution for #17760 which will introduce a new primitive, `keepAlive#`, to the `base` library, subsuming most uses of `touch#`. As always, do test this release and open tickets for whatever issues you encounter. To help with this, we will be publishing a blog post describing use of our new `head.hackage` infrastructure to ease testing of larger projects with Hackage dependencies later this week. Cheers, - Ben [1] https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0111-l… [2] https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0287-s… [3] https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0216-q… [4] https://downloads.haskell.org/ghc/9.0.1-alpha1/docs/html/users_guide/9.0.1-…

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Using a development snapshot of happy
by Vladislav Zavialov 04 Dec '20

04 Dec '20

Hi ghc-devs, I’m working on the unification of parsers for terms and types, and one of the things I’d really like to make use of is a feature I implemented in ‘happy’ in October 2019 (9 months ago): https://github.com/simonmar/happy/pull/153 It’s been merged upstream, but there has been no release of ‘happy’, despite repeated requests: 1. I asked for a release in December: https://github.com/simonmar/happy/issues/164 2. Ben asked for a release a month ago: https://github.com/simonmar/happy/issues/168 I see two solutions here: a) Find a co-maintainer for ‘happy’ who could make releases more frequently (I understand the current maintainers probably don’t have the time to do it). b) Use a development snapshot of ‘happy’ in GHC Maybe we need to do both, but one reason I’d like to see (b) in particular happen is that I can imagine introducing more features to ‘happy’ for use in GHC, and it’d be nice not to wait for a release every time. For instance, there are some changes I’d like to make to happy/alex in order to implement #17750 So here are two questions I have: 1. Are there any objections to this idea? 2. If not, could someone more familiar with the build process guide me as to how this should be implemented? Do I add ‘happy’ as a submodule and change something in the ./configure script, or is there more to it? Do I need to modify make/hadrian, and if so, then how? Thanks, - Vlad

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Use of forall as a sigil
by Bryan Richter 03 Dec '20

03 Dec '20

Dear forall ghc-devs. ghc-devs, As I read through the "Visible 'forall' in types of terms" proposal[1], I stumbled over something that isn't relevant to the proposal itself, so I thought I would bring it here. Given f :: forall a. a -> a (1) I intuitively understand the 'forall' in (1) to represent the phrase "for all". I would read (1) as "For all objects a in Hask, f is some relation from a to a." After reading the proposal, I think my intuition may be wrong, since I discovered `forall a ->`. This means something similar to, but practically different from, `forall a.`. Thus it seems like 'forall' is now simply used as a sigil to represent "here is where some special parameter goes". It could as well be an emoji. What's more, the practical difference between the two forms is *only* distinguished by ` ->` versus `.`. That's putting quite a lot of meaning into a rather small number of pixels, and further reduces any original connection to meaning that 'forall' might have had. I won't object to #281 based only on existing syntax, but I *do* object to the existing syntax. :) Is this a hopeless situation, or is there any possibility of bringing back meaning to the syntax of "dependent quantifiers"? -Bryan [1]: https://github.com/ghc-proposals/ghc-proposals/pull/281

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