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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">To be clear, I’m ok with (1), luke-warm on (2), and mildly against (3)<o:p></o:p></span></p>
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Import and export of qualified names. This seems like the Main Point.<o:p></o:p></li><li class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1">
Local import (in a let/where). This seems low pain but low gain.<o:p></o:p></li><li class="MsoNormal" style="mso-margin-top-alt:auto;mso-margin-bottom-alt:auto;mso-list:l0 level1 lfo1">
Local modules. This is the one I'm struggling with.<o:p></o:p></li></ol>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">There is more on the (tail end of the) PR
<a href="https://github.com/ghc-proposals/ghc-proposals/pull/283">https://github.com/ghc-proposals/ghc-proposals/pull/283</a><o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">I am open to being educated.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><br>
I would love to hear from other members of the committee. Tom’s thumbs-up seemed to about (1), without saying anything about (2) and (3).<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">One mechanism (if my categorisation is correct) could be to ask everyone to vote (yes/no/maybe) on all of 1,2,3.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Arnaud, you are our shepherd. Your sheep await your command.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Simon<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> ghc-steering-committee <ghc-steering-committee-bounces@haskell.org>
<b>On Behalf Of </b>Richard Eisenberg<br>
<b>Sent:</b> 19 July 2021 21:18<br>
<b>To:</b> Spiwack, Arnaud <arnaud.spiwack@tweag.io><br>
<b>Cc:</b> GHC Steering Committee <ghc-steering-committee@haskell.org><br>
<b>Subject:</b> Re: [ghc-steering-committee] #283: Local modules (again), recommendation: accept<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Any thoughts on this? Simon PJ seems lukewarm (or maybe even cooler than that), Arnaud is in support, but the rest of you have been quiet.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Thanks!<o:p></o:p></p>
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<p class="MsoNormal">Richard<o:p></o:p></p>
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<p class="MsoNormal">On Jun 11, 2021, at 3:05 AM, Spiwack, Arnaud <<a href="mailto:arnaud.spiwack@tweag.io">arnaud.spiwack@tweag.io</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Dear all,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Let me raise this proposal again. Very few of us have opined, and while I'd usually be happy to consider silence as assent, this is a rather large proposal which may require a few more pairs of eyes. Please consider giving this one a read
and share your thoughts. If you can't do so right now, please let me know when you will be able to, so that we can plan accordingly.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">This is an important proposal, I'm keen on seeing its design finalised.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">/Arnaud<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Wed, May 26, 2021 at 2:35 PM Richard Eisenberg <<a href="mailto:rae@richarde.dev">rae@richarde.dev</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On May 26, 2021, at 3:28 AM, Spiwack, Arnaud <<a href="mailto:arnaud.spiwack@tweag.io" target="_blank">arnaud.spiwack@tweag.io</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I'm realising that I inverted additional options 1 and 3 in my reply. To spell things out: I'm in favour of the namespace introduced for every datatype and such; and weakly in favour of anonymous modules, for which I prefer the `_` syntax
than simply omitting the name.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Oh, good. I was very confused here, but I decided not to push on it. I'm similarly weakly in favor of (1), but I can't get myself to decide firmly on whether to go with alternative (7). Going with (7) is a little more consistent with other
features, but it adds more symbols to the source text that could otherwise be omitted. So I'm pretty ambivalent.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Richard<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On Tue, May 25, 2021 at 11:54 PM Richard Eisenberg <<a href="mailto:rae@richarde.dev" target="_blank">rae@richarde.dev</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">On May 25, 2021, at 3:09 PM, Alejandro Serrano Mena <<a href="mailto:trupill@gmail.com" target="_blank">trupill@gmail.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">- I am not sure of the benefit of allowing (1), compared with the possible surprise of users.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">- I do not fully understand (2).<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">- I think (3) would be great, if we ensure that nothing changes if I don’t use “qualified”, even if -XLocalModules is on.<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">If in the language, I would use (1) -- anonymous local modules -- regularly, when defining a function or class instance with a bunch of "local" helper functions. Of course, if we can't omit the module name, I will suffer no great harm.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I cannot offer the guarantee you seek in (3), but I don't think you want it. (If nothing changes, then the feature has no effect!) Here is a scenario where (3) could cause trouble:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">import Data.Set as Set ( abcde )<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">data Set = Mk { abcdf :: Int }<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">blah = Set.abcdf<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Previously, GHC would have suggested that you perhaps misspelled abcde. Now, you'll get (presumably) a type error.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Here's another case:<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">import Data.Set as Set ( Set )<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">data Set = Mk<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">x :: Set.Set<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Everything is happy today, but with -XLocalModules (and (3)), the type of x is an ambiguous name.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Any example that causes trouble, though, will have something in common: an imported module name (possibly via an alias) that matches a locally defined type name. I would imagine this pattern is rare in practice, and that the benefit of
(3) would outweigh the number of times that a problem like this bites.<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">I, too, could live without (2).<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Richard<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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