<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">I must say, I agree with Richard.<div class=""><br class=""></div><div class="">Manuel<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">Am 23.03.2018 um 02:52 schrieb Richard Eisenberg <<a href="mailto:rae@cs.brynmawr.edu" class="">rae@cs.brynmawr.edu</a>>:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html charset=utf-8" class=""><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><br class=""><div class=""><blockquote type="cite" class=""><div class="">On Mar 22, 2018, at 11:15 AM, Simon Peyton Jones <<a href="mailto:simonpj@microsoft.com" class="">simonpj@microsoft.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-family: Calibri, sans-serif;" class="">Dear GHC steering committee<o:p class=""></o:p></span></p><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-family: Calibri, sans-serif;" class="">I strongly propose that we accept<o:p class=""></o:p></span></p><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><b class=""><span style="font-family: Calibri, sans-serif;" class=""> Treat kind and type vars identically with `forall` #103<o:p class=""></o:p></span></b></p><div style="margin: 6pt 0cm; font-size: 12pt; font-family: "Times New Roman", serif; text-indent: 36pt;" class=""><br class="webkit-block-placeholder"></div><div style="margin: 6pt 0cm; font-size: 12pt; font-family: "Times New Roman", serif;" class=""><br class="webkit-block-placeholder"></div></div></div></blockquote><div class=""><br class=""></div><div class="">Agreed, unsurprisingly.</div><br class=""><blockquote type="cite" class=""><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-family: Calibri, sans-serif;" class="">Moreover, I propose that we adopt it without a 3-release wait after #83 – see under Alternatives. Any programs that are rejected by #103 can be fixed by adding some extra forall k’s. And that change will be accepted NOW if you add -XTypeInType.<span class="Apple-converted-space"> </span></span></p></div></div></blockquote><div class=""><br class=""></div><div class="">Here I disagree. Enabling -XTypeInType has two unfortunate knock-on effects:</div><div class=""> - * is no longer available in kinds, without import Data.Kind. Happily, GHC gives a good error message upon a forgotten `import Data.Kind`, so this isn't so bad, but it will bite very widely.</div><div class=""> - More troublesomely, the CUSK rules are different with -XTypeInType than without. This means that turning on -XTypeInType can turn some CUSKs into non-CUSKs, producing utterly befuddling error messages. Maybe this won't bite so often, but when it does, it will take a developer a long time to sort out the problem.</div><div class=""><br class=""></div><div class="">After #83, these problems melt away, but I think it will be painful for users to support multiple versions in the meantime.</div><div class=""><br class=""></div><div class="">Richard</div><div class=""><br class=""></div><blockquote type="cite" class=""><div class=""><div class="WordSection1" style="page: WordSection1; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;"><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-family: Calibri, sans-serif;" class=""><o:p class=""></o:p></span></p><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-family: Calibri, sans-serif;" class="">Simon<o:p class=""></o:p></span></p><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><span style="font-family: Calibri, sans-serif;" class=""><o:p class=""> </o:p></span></p><p class="MsoNormal" style="margin: 6pt 0cm; font-size: 12pt; font-family: 'Times New Roman', serif;"><o:p class=""> </o:p></p></div><span style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><span style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; float: none; display: inline !important;" class="">ghc-steering-committee mailing list</span><br style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="mailto:ghc-steering-committee@haskell.org" style="color: rgb(149, 79, 114); text-decoration: underline; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">ghc-steering-committee@haskell.org</a><br style="font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class=""><a href="https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee" style="color: rgb(149, 79, 114); text-decoration: underline; font-family: Helvetica; font-size: 14px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px;" class="">https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee</a></div></blockquote></div><br class=""></div>_______________________________________________<br class="">ghc-steering-committee mailing list<br class=""><a href="mailto:ghc-steering-committee@haskell.org" class="">ghc-steering-committee@haskell.org</a><br class="">https://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-steering-committee<br class=""></div></blockquote></div><br class=""></div></body></html>