<div dir="auto">As this breaks accepted code, I’d really like to see this on two steps. At least one GHC release that warns about</div><div dir="auto"><br></div><div dir="auto"><div><pre style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;font-size:13.6px;margin-top:0px;margin-bottom:0px;padding:16px;overflow:auto;line-height:1.45;border-radius:6px;word-break:normal;font-style:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;word-spacing:0px;text-decoration:none;background-color:rgb(22,27,34);color:rgb(240,246,252)"><span class="pl-k" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-keyword)">pattern</span> <span class="pl-ent" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-entity-tag)">X</span> <span class="pl-k" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-keyword)"><-</span> <span class="pl-c1" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-constant)">42</span> <span class="pl-k" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-keyword)">::</span> <span class="pl-en" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-entity)"><span class="pl-c1" style="box-sizing:border-box;font-family:ui-monospace,SFMono-Regular,"SF Mono",Menlo,Consolas,"Liberation Mono",monospace;color:var(--color-prettylights-syntax-constant)">Int</span></span></pre></div><br></div><div dir="auto">Being rejected by GHC going forward. Thus if we get a deprecation warning for that syntax with the guidance to put the rhs into parentheses, for at least one release prior to the breaking change, I have no objections.</div><div dir="auto"><br></div><div dir="auto">Moritz</div><div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Sat, 9 Sep 2023 at 3:58 AM, Adam Gundry <<a href="mailto:adam@well-typed.com">adam@well-typed.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-style:solid;padding-left:1ex;border-left-color:rgb(204,204,204)">No objections from me. I tend not to pay too much attention to such <br>
syntactic niceties, but as the authors have gone to the trouble of <br>
surveying the community and implementing the proposal I see no reason <br>
not to accept their suggested syntax.<br>
<br>
I did notice that the PR drops Ömer's name from the authors list for <br>
#522, I'm not sure if that was intentional?<br>
<br>
Adam<br>
<br>
<br>
On 08/09/2023 18:47, Vladislav Zavialov wrote:<br>
> In favor<br>
> <br>
> On Fri, Sep 8, 2023 at 6:36 PM Simon Peyton Jones <br>
> <<a href="mailto:simon.peytonjones@gmail.com" target="_blank">simon.peytonjones@gmail.com</a> <mailto:<a href="mailto:simon.peytonjones@gmail.com" target="_blank">simon.peytonjones@gmail.com</a>>> wrote:<br>
> <br>
>     I don't have a strong opinion here.   The authors have done a pretty<br>
>     diligent job of exploring syntactic alternatives, and seeking<br>
>     feedback from the community.  I'm quite content to accept this<br>
>     proposal.  (We have already accepted the base or-pattern proposal,<br>
>     so that's not our subject for debate.)<br>
> <br>
>     Simon<br>
> <br>
>     On Fri, 8 Sept 2023 at 03:57, Chris Dornan <<a href="mailto:chris@chrisdornan.com" target="_blank">chris@chrisdornan.com</a><br>
>     <mailto:<a href="mailto:chris@chrisdornan.com" target="_blank">chris@chrisdornan.com</a>>> wrote:<br>
> <br>
>         Proposal: Amend or patterns (#522) to use p1 ; p2 (#609)<br>
>         Author: Sebastian Graf, David Knothe<br>
>         Rendered proposal:<br>
>         <a href="https://github.com/ghc-proposals/ghc-proposals/blob/eb4b67c29282520b2c5c6a49c3047dbecb15dde1/proposals/0522-or-patterns.rst" rel="noreferrer" target="_blank">https://github.com/ghc-proposals/ghc-proposals/blob/eb4b67c29282520b2c5c6a49c3047dbecb15dde1/proposals/0522-or-patterns.rst</a> <<a href="https://github.com/ghc-proposals/ghc-proposals/blob/eb4b67c29282520b2c5c6a49c3047dbecb15dde1/proposals/0522-or-patterns.rst" rel="noreferrer" target="_blank">https://github.com/ghc-proposals/ghc-proposals/blob/eb4b67c29282520b2c5c6a49c3047dbecb15dde1/proposals/0522-or-patterns.rst</a>><br>
>         Discussion:<br>
>         <a href="https://github.com/ghc-proposals/ghc-proposals/pull/609" rel="noreferrer" target="_blank">https://github.com/ghc-proposals/ghc-proposals/pull/609</a><br>
>         <<a href="https://github.com/ghc-proposals/ghc-proposals/pull/609" rel="noreferrer" target="_blank">https://github.com/ghc-proposals/ghc-proposals/pull/609</a>><br>
>         Recommendation: Acceptance<br>
> <br>
>         ## Summary<br>
> <br>
>         This proposal refines the syntax of an already accpted proposal<br>
>         (#522) for writing or patterns.<br>
> <br>
>         The syntax of the old proposal,<br>
> <br>
>         ```haskell<br>
>         stringOfT :: T -> Maybe String<br>
>         stringOfT (T1 s) = Just s<br>
>         stringOfT (one of T2{}, T3{}) = Nothing<br>
>         ```<br>
> <br>
>         is replaced with<br>
> <br>
>         ```haskell<br>
>         stringOfT :: T -> Maybe String<br>
>         stringOfT (T1 s) = Just s<br>
>         stringOfT (T2{}; T3{}) = Nothing<br>
>         ```<br>
> <br>
>         or indeed<br>
> <br>
>         ```haskell<br>
>         stringOfT :: T -> Maybe String<br>
>         stringOfT x = case x of<br>
>         T1 s -> Just s<br>
>         T2{}<br>
>         T3{} -> Nothing<br>
>         ```<br>
> <br>
>         (Beacuse the '(' ... ')' are optional here, we can remove them<br>
>         and naturally exploit layout.)<br>
> <br>
>         The authors have conducted polls to see what folks preferred,<br>
>         landing on this proposal. The<br>
>         adjustments to the Haskell grammar are really quite minimal<br>
>         requiring one extra production.<br>
> <br>
>         ## Recommendation<br>
> <br>
>         The proposal is nondiruptive and as a whole addresses an<br>
>         important practical topic. I recommend<br>
>         that we accept it<br>
> <br>
<br>
<br>
-- <br>
Adam Gundry, Haskell Consultant<br>
Well-Typed LLP, <a href="https://www.well-typed.com/" rel="noreferrer" target="_blank">https://www.well-typed.com/</a><br>
<br>
Registered in England & Wales, OC335890<br>
27 Old Gloucester Street, London WC1N 3AX, England<br>
<br>
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</blockquote></div></div>