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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">Dear GHC users,&nbsp;
<o:p></o:p></span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
<o:p></o:p></b></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b>Carter</b>: Will this RTS update make it into ghc 7.8 update thats coming up in the next monthish?<o:p></o:p></p>
<p class="MsoNormal" style="margin-left:36.0pt"><b>Andreas</b>: We are almost there - we are now trying to sort out a problem on mac os x.&nbsp;It would be helpful to know if there is a cutoff date for getting things into 7.8.&nbsp;<o:p></o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">Simon, Ian, and I have just been discussing 7.8, and would be interested in what you guys think.&nbsp;
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><br>
At ICFP we speculated that we&#8217;d make a release of GHC soon after Christmas to embody tons of stuff that has been included since 7.6, specifically:<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">major improvements in DPH (vectorisation avoidance, new vectoriser)<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">type holes<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">rebindable list syntax<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">major changes to the type inference engine<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">type level natural numbers<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">overlapping type families<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">the new code generator<o:p></o:p></span></p>
<p class="MsoPlainText" style="margin-left:36.0pt;text-indent:-18.0pt;mso-list:l1 level1 lfo1">
<![if !supportLists]><span style="font-family:Symbol;color:#1F497D;mso-fareast-language:EN-GB"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D;mso-fareast-language:EN-GB">support for vector (SSE/AVX) instructions<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">Whenever it comes it would definitely be great to include Andreas &amp; friends&#8217; work:<o:p></o:p></span></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="font-size:11.0pt;font-family:Symbol;color:#1F497D"><span style="mso-list:Ignore"><span style="font:7.0pt &quot;Times New Roman&quot;">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</span></span></span><![endif]><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">Scheduler changes to the RTS to improve latency<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">The original major reason for proposing a post-Xmas release was to get DPH in a working state out into the wild.&nbsp; However, making a proper release imposes costs
 on everyone else.&nbsp; Library authors have to scurry around to make their libraries work, etc.&nbsp; &nbsp;Some of the new stuff hasn&#8217;t been in HEAD for that long, and hence has not been very thoroughly tested.&nbsp;&nbsp; (But of course making a release unleashes a huge wave of
 testing that doesn&#8217;t happen otherwise.)<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">So another alternative is to leave it all as HEAD, and wait another few months before making a release.&nbsp; You can still use all the new stuff by compiling HEAD,
 or grabbing a snapshot distribution.&nbsp; And it makes it hard for the Haskell platform if GHC moves too fast. Many people are still on 7.4.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">There seem to be pros and cons each way.&nbsp; I don&#8217;t have a strong opinion.&nbsp; If you have a view, let us know.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D">Simon<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:&quot;Verdana&quot;,&quot;sans-serif&quot;;color:#1F497D"><o:p>&nbsp;</o:p></span></p>
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