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<h3 style="margin-top: 20px; margin-bottom: 10px;">
Marge Bot pushed to branch wip/marge_bot_batch_merge_job 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/188b280d767762350d453d7772198a5666ba5f23">188b280d</a></strong>
<div>
<span> by Arnaud Spiwack </span> <i> at 2023-12-11T15:33:31+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "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;'>LinearTypes => MonoLocalBinds
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8e0446dfd79099403d005e04f63ea49496b1cab3">8e0446df</a></strong>
<div>
<span> by Arnaud Spiwack </span> <i> at 2023-12-11T15:44:28+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "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;'>Linear let and where bindings
For expediency, the initial implementation of linear types in GHC
made it so that let and where binders would always be considered
unrestricted. This was rather unpleasant, and probably a big obstacle
to adoption. At any rate, this was not how the proposal was designed.
This patch fixes this infelicity. It was surprisingly difficult to
build, which explains, in part, why it took so long to materialise.
As of this patch, let or where bindings marked with %1 will be
linear (respectively %p for an arbitrary multiplicity p). Unmarked let
will infer their multiplicity.
Here is a prototypical example of program that used to be rejected and
is accepted with this patch:
```haskell
f :: A %1 -> B
g :: B %1 -> C
h :: A %1 -> C
h x = g y
where
y = f x
```
Exceptions:
- Recursive let are unrestricted, as there isn't a clear semantics of
what a linear recursive binding would be.
- Destructive lets with lazy bindings are unrestricted, as their
desugaring isn't linear (see also #23461).
- (Strict) destructive lets with inferred polymorphic type are
unrestricted. Because the desugaring isn't linear (See #18461
down-thread).
Closes #18461 and #18739
Co-authored-by: @jackohughes
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6b1335c24ce7166329e6441e8d141a403703d26a">6b1335c2</a></strong>
<div>
<span> by Matthew Craven </span> <i> at 2023-12-11T22:45:46-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "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;'>Introduce `dataToTagSmall#` primop (closes #21710)
...and use it to generate slightly better code when dataToTag#
is used at a "small data type" where there is no need to mess
with "is_too_big_tag" or potentially look at an info table.
Metric Decrease:
T18304
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/53a54c2f6a08d2e85fdb731d0d95e508ec5645f5">53a54c2f</a></strong>
<div>
<span> by Matthew Craven </span> <i> at 2023-12-11T22:45:46-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "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;'>Fix formatting of Note [alg-alt heap check]
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a0c7713a0e48502a2ea86ace4d1914649d267973">a0c7713a</a></strong>
<div>
<span> by Oleg Grenrus </span> <i> at 2023-12-11T22:45:47-05:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "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;'>Allow untyped brackets in typed splices and vice versa.
Resolves #24190
Apparently the check was essentially always (as far as I can trace back: d0d47ba76f8f0501cf3c4966bc83966ab38cac27),
and while it does catch some mismatches, the type-checker will catch
them too. OTOH, it prevents writing completely reasonable programs.
</pre>
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30 changed files:
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<a href="#a1519b7fe8a0d4b42e4aaa927fb6ab5b5da0fcdd">
compiler/GHC/Builtin/PrimOps.hs
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<a href="#451725cc4e5d443a3b7c2adcdf224840f953b7e2">
compiler/GHC/Builtin/primops.txt.pp
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compiler/GHC/Core.hs
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compiler/GHC/Core/Lint.hs
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compiler/GHC/Core/Opt/ConstantFold.hs
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compiler/GHC/Driver/Session.hs
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compiler/GHC/Hs/Binds.hs
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compiler/GHC/Hs/Instances.hs
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compiler/GHC/Hs/Utils.hs
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compiler/GHC/HsToCore/Arrows.hs
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compiler/GHC/HsToCore/Binds.hs
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compiler/GHC/HsToCore/Expr.hs
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compiler/GHC/HsToCore/ListComp.hs
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compiler/GHC/HsToCore/Match.hs
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compiler/GHC/HsToCore/Match.hs-boot
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compiler/GHC/HsToCore/Utils.hs
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compiler/GHC/Parser.y
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compiler/GHC/Parser/PostProcess.hs
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compiler/GHC/Rename/Bind.hs
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compiler/GHC/Rename/Splice.hs
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compiler/GHC/Stg/InferTags/Rewrite.hs
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compiler/GHC/StgToCmm/Expr.hs
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compiler/GHC/StgToCmm/Prim.hs
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compiler/GHC/StgToJS/Prim.hs
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compiler/GHC/Tc/Gen/Bind.hs
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compiler/GHC/Tc/Gen/Expr.hs
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compiler/GHC/Tc/Gen/Match.hs
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compiler/GHC/Tc/Gen/Match.hs-boot
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compiler/GHC/Tc/Gen/Pat.hs
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The diff was not included because it is too large.
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