carbon-language/carbon-lang
1
0
Fork 0
mirror of https://github.com/carbon-language/carbon-lang.git synced 2026-10-05 22:02:55 +01:00
Code Issues Packages Projects Releases 10 Wiki Activity

Drop Singleton from ErrorInst::SingletonInstId and similar (#5304)

Browse Source 
We frequently want to operate on singletons. Per discussion, drop
`Singleton` to make the code shorter.

This started off as wanting to write `inst_id.is_error()`, but the
dependency relationship between ids.h and singleton_insts.h would
require some kind of delayed evaluation to allow the implementation to
remain in headers (which I suspect is helpful to have for inlining). I
could have added something like `IsErrorInst`, forward declared in ids.h
and defined in singleton_insts.h (which would always be included by
typed_insts.h), but the template approach felt like a decent balance
between (a) removing the boilerplate `::SingletonInstId`, (b)
understandability, (c) still visually mirroring if we immediately return
a singleton, and (d) flexibility for more than just `ErrorInst`. But TBH
I'd probably still have written `is_error()` if it didn't require
addressing the cross-header cycle.

Then I tried `SemIR::InstId::Is<SemIR::ErrorInst>`, which generally
worked with types but generated the complaint that it didn't shorten
*all* singleton uses. So pulling back on `::Is`, and instead just
dropping `Singleton`.
This commit is contained in:
Jon Ross-Perkins
2025-04-15 22:40:29 +00:00
committed by GitHub
parent 838417e358
commit 4923445e3a
64 changed files with 489 additions and 539 deletions
Download Patch File Download Diff File Expand all files Collapse all files
toolchain/check/handle_alias.cpp
+2 -2
View File
@@ -56,8 +56,8 @@ auto HandleParseNode(Context& context, Parse::AliasId /*node_id*/) -> bool {
CARBON_DIAGNOSTIC(AliasRequiresNameRef, Error,
"alias initializer must be a name reference");
context.emitter().Emit(expr_node, AliasRequiresNameRef);
alias_type_id = SemIR::ErrorInst::SingletonTypeId;
alias_value_id = SemIR::ErrorInst::SingletonInstId;
alias_type_id = SemIR::ErrorInst::TypeId;
alias_value_id = SemIR::ErrorInst::InstId;
}
auto alias_id = AddInst<SemIR::BindAlias>(context, name_context.loc_id,
{.type_id = alias_type_id,