<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html lang="en" style="--code-editor-font: GitLab Mono, JetBrains Mono, Menlo, DejaVu Sans Mono, Liberation Mono, Consolas, Ubuntu Mono, Courier New, andale mono, lucida console, monospace;">
<head>
<meta content="text/html; charset=US-ASCII" http-equiv="Content-Type">
<title>
GitLab
</title>
<style data-premailer="ignore" type="text/css">
a { color: #1068bf; }
</style>
<style>img {
max-width: 100%; height: auto;
}
body {
font-size: 0.875rem;
}
body {
-webkit-text-shadow: rgba(255,255,255,0.01) 0 0 1px;
}
body {
font-family: "GitLab Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans", Ubuntu, Cantarell, "Helvetica Neue", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji"; font-size: inherit;
}
</style>
</head>
<body style='font-size: inherit; -webkit-text-shadow: rgba(255,255,255,0.01) 0 0 1px; font-family: "GitLab Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans", Ubuntu, Cantarell, "Helvetica Neue", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";'>
<div class="content">
<h3 style="margin-top: 20px; margin-bottom: 10px;">
David pushed to branch wip/or-pats at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
Commits:
</h4>
<ul>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/50f574d13ef9caec295e70455e3c1d0f44a3c40d">50f574d1</a></strong>
<div>
<span> by David Knothe </span> <i> at 2023-07-31T17:59:42+02:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: "GitLab Mono", "JetBrains Mono", "Menlo", "DejaVu Sans Mono", "Liberation Mono", "Consolas", "Ubuntu Mono", "Courier New", "andale mono", "lucida console", monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Implement Or Patterns (Proposal 0522)
This commit introduces a language extension, `OrPatterns`, as described in proposal 0522.
It extends the syntax by the production
`pat -> (one of pat1, ..., patk)`.
The or-pattern `pat` succeeds iff one of the patterns `pat1`, ..., `patk` succeed, in this order.
Currently, or-patterns cannot bind variables. They are still of great use as they discourage the use of wildcard patterns in favour of writing out all "default" cases explicitly:
```
isIrrefutableHsPat pat = case pat of
...
(one of WildPat{}, VarPat{}, LazyPat{})
= True
(one of PArrPat{}, ConPatIn{}, LitPat{}, NPat{}, NPlusKPat{}, ListPat{})
= False
```
This makes code safer where data types are extended now and then - just like GHC's `Pat` in the example when adding the new `OrPat` constructor. This would be catched by `-fwarn-incomplete-patterns`, but not when a wildcard pattern was used.
- Update submodule haddock.
stuff
Implement empty one of
Prohibit TyApps
Remove unused
update submodule haddock
Update tests
Parser.y
</pre>
</li>
</ul>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
30 changed files:
</h4>
<ul>
<li class="file-stats">
<a href="#774d88050336ef660c7a219fb06c480c2fc639bc">
compiler/GHC/Driver/Session.hs
</a>
</li>
<li class="file-stats">
<a href="#0bae7e7e67b5f9b6ba2a371f8917cf74423a0c6f">
compiler/GHC/Hs/Pat.hs
</a>
</li>
<li class="file-stats">
<a href="#f5160f63851d2edcbf12e12247c1b078cf40f20a">
compiler/GHC/Hs/Syn/Type.hs
</a>
</li>
<li class="file-stats">
<a href="#7a1af22e4c32b9aa6ec708d9d3788e1c4db5da9a">
compiler/GHC/Hs/Utils.hs
</a>
</li>
<li class="file-stats">
<a href="#085703923f9c18f6ac9f926ac9a4c7c7e6d9d9ed">
compiler/GHC/HsToCore/Match.hs
</a>
</li>
<li class="file-stats">
<a href="#3050d0d7e4a9e93aebcc1fe0bed898ca6dac5502">
compiler/GHC/HsToCore/Pmc/Check.hs
</a>
</li>
<li class="file-stats">
<a href="#950eaa7de202a2e915b5ff68a4cfd16e972ad359">
compiler/GHC/HsToCore/Pmc/Desugar.hs
</a>
</li>
<li class="file-stats">
<a href="#0036eccef60579fe5f653a10eeb8bf9869964cf4">
compiler/GHC/HsToCore/Pmc/Types.hs
</a>
</li>
<li class="file-stats">
<a href="#94864be2e2eb1959a038d5d903a6c784e5cfb32a">
compiler/GHC/HsToCore/Utils.hs
</a>
</li>
<li class="file-stats">
<a href="#649144a78135a23cabfc90dd83c4aabf448eb6ab">
compiler/GHC/Iface/Ext/Ast.hs
</a>
</li>
<li class="file-stats">
<a href="#bf951467d4a9aa443cb109cb4c84a2891945649b">
compiler/GHC/Parser.y
</a>
</li>
<li class="file-stats">
<a href="#b1092d2df4ded3655524830252278016d6aa5afd">
compiler/GHC/Parser/Annotation.hs
</a>
</li>
<li class="file-stats">
<a href="#4769efc0cb06e92bc7562e31984f6d7d91048e51">
compiler/GHC/Parser/Errors/Ppr.hs
</a>
</li>
<li class="file-stats">
<a href="#6bd0eb7fd0a01f3d8cf2efe3f1d026d2145cf10b">
compiler/GHC/Parser/Errors/Types.hs
</a>
</li>
<li class="file-stats">
<a href="#a1ae0a1be35c859d90b0756920a7198075fb91e1">
compiler/GHC/Parser/Lexer.x
</a>
</li>
<li class="file-stats">
<a href="#446cb12ca6cefaf1c6eb79b7db643632744263c7">
compiler/GHC/Parser/PostProcess.hs
</a>
</li>
<li class="file-stats">
<a href="#af762064d779f7308dd415966c974f27d14f9943">
compiler/GHC/Rename/Bind.hs
</a>
</li>
<li class="file-stats">
<a href="#b47ece2bbb8303a5792c2fdc52394c8ed336e8a2">
compiler/GHC/Rename/Expr.hs
</a>
</li>
<li class="file-stats">
<a href="#cfa41b5649933e5b12f7796e9d49b9dd6a0bc59f">
compiler/GHC/Rename/Pat.hs
</a>
</li>
<li class="file-stats">
<a href="#1dd9c7a6bbc222c976a6ec1c4b772232ae60f7e5">
compiler/GHC/Tc/Errors/Ppr.hs
</a>
</li>
<li class="file-stats">
<a href="#cdba811872892f235fe7059df1a6c538fba60816">
compiler/GHC/Tc/Errors/Types.hs
</a>
</li>
<li class="file-stats">
<a href="#3ee8be814b6c6727880deab3772e6af922524bf0">
compiler/GHC/Tc/Gen/Pat.hs
</a>
</li>
<li class="file-stats">
<a href="#5c0a7f8291c984f0fc06f59e7cf10dbecc11598b">
compiler/GHC/Tc/TyCl/PatSyn.hs
</a>
</li>
<li class="file-stats">
<a href="#70276ecbf78c4d6abaaaba692722a2a4e2e46167">
compiler/GHC/Tc/Zonk/Type.hs
</a>
</li>
<li class="file-stats">
<a href="#e2c828ee9e003df518a07b05beaa6971e5c62eb0">
compiler/GHC/Types/Error/Codes.hs
</a>
</li>
<li class="file-stats">
<a href="#d3cf57b6a5ebc234dc7689db38ef9b6cf2259c0f">
compiler/GHC/Utils/Outputable.hs
</a>
</li>
<li class="file-stats">
<a href="#55fd4da29695073f23c02f21476e753eb7c467b4">
compiler/Language/Haskell/Syntax/Extension.hs
</a>
</li>
<li class="file-stats">
<a href="#f92237bbf761245188d3b0de16bb685b3eaa2b60">
compiler/Language/Haskell/Syntax/Pat.hs
</a>
</li>
<li class="file-stats">
<a href="#3d17c4f6535facac120d29a4c86df4b769769c25">
<span class="new-file">
+
docs/users_guide/exts/or_patterns.rst
</span>
</a>
</li>
<li class="file-stats">
<a href="#7b32ad32b2a132ff2f81a2ae79a0ebc31dace9d2">
docs/users_guide/exts/patterns.rst
</a>
</li>
</ul>
<h5 style="margin-top: 10px; margin-bottom: 10px; font-size: 0.875rem;">
The diff was not included because it is too large.
</h5>
</div>
<div class="footer" style="margin-top: 10px;">
<p style="font-size: small; color: #737278;">
—
<br>
<a href="https://gitlab.haskell.org/ghc/ghc/-/commit/50f574d13ef9caec295e70455e3c1d0f44a3c40d">View it on GitLab</a>.
<br>
You're receiving this email because of your account on <a target="_blank" rel="noopener noreferrer" href="https://gitlab.haskell.org">gitlab.haskell.org</a>. <a href="https://gitlab.haskell.org/-/profile/notifications" target="_blank" rel="noopener noreferrer" class="mng-notif-link">Manage all notifications</a> · <a href="https://gitlab.haskell.org/help" target="_blank" rel="noopener noreferrer" class="help-link">Help</a>
<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/50f574d13ef9caec295e70455e3c1d0f44a3c40d"}}</script>
</p>
</div>
</body>
</html>