<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html lang="en">
<head>
<meta content="text/html; charset=US-ASCII" http-equiv="Content-Type">
<title>
GitLab
</title>
<style>img {
max-width: 100%; height: auto;
}
</style>
</head>
<body>
<div class="content">
<h3>
Richard Eisenberg pushed to branch wip/cfuneqcan-refactor
at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4>
Commits:
</h4>
<ul>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/16e56ac19b1b72223093b95bb462875c73289554">16e56ac1</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-10-11T11:21:36-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Expand synonyms that mention families, obvs
</pre>
</li>
</ul>
<h4>1 changed file:</h4>
<ul>
<li class="file-stats">
<a href="#81707f1fe21087531cefd70879aa09c2be5c1d22">
compiler/GHC/Tc/Solver/Flatten.hs
</a>
</li>
</ul>
<h4>Changes:</h4>
<li id="81707f1fe21087531cefd70879aa09c2be5c1d22">
<a href="https://gitlab.haskell.org/ghc/ghc/-/commit/16e56ac19b1b72223093b95bb462875c73289554#81707f1fe21087531cefd70879aa09c2be5c1d22"><strong>compiler/GHC/Tc/Solver/Flatten.hs</strong></a>
<hr>
<table class="code white" style="font-family: monospace; font-size: 90%;" bgcolor="#fff" width="100%" cellpadding="0" cellspacing="0">
<tr class="line_holder match" id="" style="line-height: 1.6;">
<td class="diff-line-num unfold js-unfold old_line" data-linenumber="1126" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">...</td>
<td class="diff-line-num unfold js-unfold new_line" data-linenumber="1126" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">...</td>
<td class="line_content match " style="padding-left: 0.5em; padding-right: 0.5em; color: rgba(0,0,0,0.3);" bgcolor="#fafafa">@@ -1126,8 +1126,8 @@ flatten_one (AppTy ty1 ty2)</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1126" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1126
</td>
<td class="diff-line-num new_line" data-linenumber="1126" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1126
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1126" class="line" lang="haskell"><span class="n" style="color: #333;">flatten_one</span> <span class="n" style="color: #333;">ty</span><span class="o" style="font-weight: 600;">@</span><span class="p">(</span><span class="kt" style="color: #458; font-weight: 600;">TyConApp</span> <span class="n" style="color: #333;">tc</span> <span class="n" style="color: #333;">tys</span><span class="p">)</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1127" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1127
</td>
<td class="diff-line-num new_line" data-linenumber="1127" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1127
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1127" class="line" lang="haskell"> <span class="c1" style="color: #998; font-style: italic;">-- Expand type synonyms that mention type families</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1128" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1128
</td>
<td class="diff-line-num new_line" data-linenumber="1128" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1128
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1128" class="line" lang="haskell"> <span class="c1" style="color: #998; font-style: italic;">-- on the RHS; see Note [Flattening synonyms]</span></span>
</pre>
</td>
</tr>
<tr class="line_holder old" id="" style="line-height: 1.6;">
<td class="diff-line-num old old_line" data-linenumber="1129" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#f9d7dc">
1129
</td>
<td class="diff-line-num new_line old" data-linenumber="1129" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#f9d7dc">
</td>
<td class="line_content old" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#fbe9eb">
<pre style="margin: 0;">-<span id="LC1129" class="line" lang="haskell"> <span class="o" style="font-weight: 600;">|</span> <span class="n" style="color: #333;">isForgetfulSynTyCon</span> <span class="n" style="color: #333;">tc</span></span>
</pre>
</td>
</tr>
<tr class="line_holder old" id="" style="line-height: 1.6;">
<td class="diff-line-num old old_line" data-linenumber="1130" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#f9d7dc">
1130
</td>
<td class="diff-line-num new_line old" data-linenumber="1129" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #fac5cd; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#f9d7dc">
</td>
<td class="line_content old" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#fbe9eb">
<pre style="margin: 0;">-<span id="LC1130" class="line" lang="haskell"> <span class="p">,</span> <span class="kt" style="color: #458; font-weight: 600;">Just</span> <span class="n" style="color: #333;">expanded_ty</span> <span class="o" style="font-weight: 600;"><-</span> <span class="n" style="color: #333;">tcView</span> <span class="n" style="color: #333;">ty</span><span class="idiff left"> </span><span class="c1" style="color: #998; font-style: italic;"><span class="idiff right">-- should always succeed</span></span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="1131" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="1129" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
1129
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC1129" class="line" lang="haskell"> <span class="o" style="font-weight: 600;">|</span> <span class="n" style="color: #333;">isForgetfulSynTyCon</span> <span class="n" style="color: #333;">tc</span><span class="idiff left"> </span><span class="o" style="font-weight: 600;"><span class="idiff">||</span></span><span class="idiff"> </span><span class="n" style="color: #333;"><span class="idiff">not</span></span><span class="idiff"> </span><span class="p"><span class="idiff">(</span></span><span class="n" style="color: #333;"><span class="idiff">isFamFreeTyCon</span></span><span class="idiff"> </span><span class="n" style="color: #333;"><span class="idiff">tc</span></span><span class="p"><span class="idiff right">)</span></span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="1131" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="1130" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
1130
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC1130" class="line" lang="haskell"> <span class="p">,</span> <span class="kt" style="color: #458; font-weight: 600;">Just</span> <span class="n" style="color: #333;">expanded_ty</span> <span class="o" style="font-weight: 600;"><-</span> <span class="n" style="color: #333;">tcView</span> <span class="n" style="color: #333;">ty</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1131" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1131
</td>
<td class="diff-line-num new_line" data-linenumber="1131" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1131
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1131" class="line" lang="haskell"> <span class="o" style="font-weight: 600;">=</span> <span class="n" style="color: #333;">flatten_one</span> <span class="n" style="color: #333;">expanded_ty</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1132" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1132
</td>
<td class="diff-line-num new_line" data-linenumber="1132" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1132
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1132" class="line" lang="haskell"></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1133" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1133
</td>
<td class="diff-line-num new_line" data-linenumber="1133" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1133
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1133" class="line" lang="haskell"> <span class="c1" style="color: #998; font-style: italic;">-- Otherwise, it's a type function application, and we have to</span></span>
</pre>
</td>
</tr>
<tr class="line_holder match" id="" style="line-height: 1.6;">
<td class="diff-line-num unfold js-unfold old_line" data-linenumber="1309" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">...</td>
<td class="diff-line-num unfold js-unfold new_line" data-linenumber="1309" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">...</td>
<td class="line_content match " style="padding-left: 0.5em; padding-right: 0.5em; color: rgba(0,0,0,0.3);" bgcolor="#fafafa">@@ -1309,6 +1309,9 @@ synonyms, but not others.</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1309" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1309
</td>
<td class="diff-line-num new_line" data-linenumber="1309" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1309
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1309" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">One nice consequence is that we never have to occCheckExpand flattened</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1310" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1310
</td>
<td class="diff-line-num new_line" data-linenumber="1310" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1310
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1310" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">types, as any forgetful synonyms are already expanded.</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1311" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1311
</td>
<td class="diff-line-num new_line" data-linenumber="1311" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1311
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1311" class="line" lang="haskell"></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="1312" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="1312" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
1312
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC1312" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">We also, of course, must expand type synonyms that mention type families,</span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="1312" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="1313" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
1313
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC1313" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">so those families can get reduced.</span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="1312" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="1314" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
1314
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC1314" class="line" lang="haskell"></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1312" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1312
</td>
<td class="diff-line-num new_line" data-linenumber="1315" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1315
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1315" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">Note [Flattening under a forall]</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1313" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1313
</td>
<td class="diff-line-num new_line" data-linenumber="1316" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1316
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1316" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="1314" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1314
</td>
<td class="diff-line-num new_line" data-linenumber="1317" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
1317
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC1317" class="line" lang="haskell"><span class="cm" style="color: #998; font-style: italic;">Under a forall, we</span></span>
</pre>
</td>
</tr>
</table>
<br>
</li>
</div>
<div class="footer" style="margin-top: 10px;">
<p style="font-size: small; color: #777;">
—
<br>
<a href="https://gitlab.haskell.org/ghc/ghc/-/commit/16e56ac19b1b72223093b95bb462875c73289554">View it on GitLab</a>.
<br>
You're receiving this email because of your account on gitlab.haskell.org.
If you'd like to receive fewer emails, you can
adjust your notification settings.
<script type="application/ld+json">{"@context":"http://schema.org","@type":"EmailMessage","action":{"@type":"ViewAction","name":"View Commit","url":"https://gitlab.haskell.org/ghc/ghc/-/commit/16e56ac19b1b72223093b95bb462875c73289554"}}</script>
</p>
</div>
</body>
</html>