<div dir="ltr">Simon PJ argues for "value" over "data" as a specifier: <a href="https://github.com/ghc-proposals/ghc-proposals/pull/167#issuecomment-470947193">https://github.com/ghc-proposals/ghc-proposals/pull/167#issuecomment-470947193</a><div><br></div><div>I'm fine with this choice either (and I'm satisfied with the argument that deprecating or setting fixity for value "value" is a rare case to be considered seriously). If you have another opinion, please, speak up.</div><div><br></div><div>Vitaly</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Mar 8, 2019 at 11:42 AM Simon Peyton Jones <<a href="mailto:simonpj@microsoft.com">simonpj@microsoft.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">





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<p class="MsoNormal"><span>I’ve made a post on the proposal thread asking why we don’t just follow the already-adopted proposal for WARNING and infix pragmas.<u></u><u></u></span></p></div></div><div lang="EN-GB" link="blue" vlink="purple"><div class="m_-163251373067047859WordSection1">
<p class="MsoNormal"><span><u></u> <u></u></span></p>
<p class="MsoNormal"><span>Simon<u></u><u></u></span></p></div></div><div lang="EN-GB" link="blue" vlink="purple"><div class="m_-163251373067047859WordSection1">
<p class="MsoNormal"><span><u></u> <u></u></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> ghc-steering-committee <<a href="mailto:ghc-steering-committee-bounces@haskell.org" target="_blank">ghc-steering-committee-bounces@haskell.org</a>>
<b>On Behalf Of </b>Simon Marlow<br>
<b>Sent:</b> 08 March 2019 07:57<br>
<b>To:</b> Vitaly Bragilevsky <<a href="mailto:bravit111@gmail.com" target="_blank">bravit111@gmail.com</a>><br>
<b>Cc:</b> ghc-steering-committee <<a href="mailto:ghc-steering-committee@haskell.org" target="_blank">ghc-steering-committee@haskell.org</a>><br>
<b>Subject:</b> Re: [ghc-steering-committee] #167: Deprecated Entities, rec: accept<u></u><u></u></span></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Yes, I think this is the right way to go.<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Cheers<u></u><u></u></p>
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<p class="MsoNormal">Simon<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">On Fri, 8 Mar 2019 at 05:25, Vitaly Bragilevsky <<a href="mailto:bravit111@gmail.com" target="_blank">bravit111@gmail.com</a>> wrote:<u></u><u></u></p>
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<p class="MsoNormal">Hi everyone, <u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">I was asked to shepherd the proposal #167 (Deprecated Entities,
<a href="https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fnineonine%2Fghc-proposals%2Fblob%2Fdepr-entities%2Fproposals%2F0000-deprecated-entities.rst&data=02%7C01%7Csimonpj%40microsoft.com%7C29c80f1b5e6e43273aaa08d6a39bbdbb%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636876286630814000&sdata=sJ3QiAx6Z55hJvsYajJEKfx6M8IVZ2DEY4LRRiaBTI8%3D&reserved=0" target="_blank">
https://github.com/nineonine/ghc-proposals/blob/depr-entities/proposals/0000-deprecated-entities.rst</a>). It is proposed to extend (nonpositional) DEPRECATED pragma with the two specifiers to disambiguate deprecating named type-level and value-level things.
 In its current formulation, the proposal suggests to use the specifiers "type" for type-level things and "pattern" for value-level things as follows:<br>
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data Bar = Bar<u></u><u></u></p>
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<p class="MsoNormal">{-# DEPRECATED type Bar "Don't use type Bar" #-} <u></u><u></u></p>
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<p class="MsoNormal">data Baz = Baz<u></u><u></u></p>
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<p class="MsoNormal">{-# DEPRECATED pattern Baz "Don't use data constructor Baz" #-}<br>
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Using this pragma without specifiers should mean deprecating both (as is works now).<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">After discussing this proposal within the committee (see <a href="https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fmail.haskell.org%2Fpipermail%2Fghc-steering-committee%2F2019-February%2F000894.html&data=02%7C01%7Csimonpj%40microsoft.com%7C29c80f1b5e6e43273aaa08d6a39bbdbb%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636876286630824013&sdata=DEu9cf6sX2xf%2BxegCrh1TikJT%2B3yWB3BgA1k9CmCLs4%3D&reserved=0" target="_blank">
https://mail.haskell.org/pipermail/ghc-steering-committee/2019-February/000894.html</a>), I recommend acceptance with one change, namely using "data" instead of "pattern" for deprecating value-level things. <u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Reasons for choosing "data":<u></u><u></u></p>
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<p class="MsoNormal">* it's a reserved keyword (as opposed to "value", which is another option)<u></u><u></u></p>
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<p class="MsoNormal">* we are deprecating data constructors here<u></u><u></u></p>
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<p class="MsoNormal">* it just feels right (sorry!)<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Reasons against "data":<u></u><u></u></p>
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<p class="MsoNormal">* it can be confusing whether we mean data type or data constructor<u></u><u></u></p>
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<p class="MsoNormal">* we use "value" and "pattern" in other places meaning basically the same thing<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">If the committee decides to go this way, then the wider community may think about other proposals, such as<u></u><u></u></p>
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<p class="MsoNormal">* adding positional DEPRECATED pragmas (including class instances deprecation)<u></u><u></u></p>
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<p class="MsoNormal">* fixing inconsistencies with the fixity declarations (<a href="https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fghc-proposals%2Fghc-proposals%2Fblob%2Fmaster%2Fproposals%2F0008-type-infix.rst&data=02%7C01%7Csimonpj%40microsoft.com%7C29c80f1b5e6e43273aaa08d6a39bbdbb%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C636876286630834021&sdata=IrpWyWLVksadQK5bo%2B7d%2B10LWuztYUcFwkAUsZxA5cg%3D&reserved=0" target="_blank">https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0008-type-infix.rst</a>)
 and updating ExplicitNamespaces in import/export lists<u></u><u></u></p>
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<p class="MsoNormal">* deprecating usage of nonpositional DEPRECATED pragma without the specifiers<u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Silence is understood as agreement. <u></u><u></u></p>
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<p class="MsoNormal"><u></u> <u></u></p>
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<p class="MsoNormal">Regards, <u></u><u></u></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Vitaly<br>
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<u></u><u></u></p>
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<p class="MsoNormal">_______________________________________________<br>
ghc-steering-committee mailing list<br>
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