Dollars in idents#24690
Dollars in idents #24690
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sjrd commented Dec 7, 2025
They should not be written at all, in fact. ;) |
som-snyttforce-pushed the issue/18234-dollar-idents branch from 965c5f3 to 3690e96Compare
This proposal aims to accommodate the two views, which are not entirely incompatible, that strict enforcement is required and yet Java doesn't need it so why does Scala?, where the question is posed with a large dosage of skepticism about warnings. Here, there is no forking compiler option. Definitions with suspect names are disallowed, with a migration warning now and an error later. However, the workaround, to permit the identifier in backquotes, is quite natural and pleasant, as we have all come to savor backquotes in new syntactic contexts. Backquotes are not required for references (usages). CB A |
som-snyttforce-pushed the issue/18234-dollar-idents branch from 3690e96 to 3fe96a5Comparesom-snyttforce-pushed the issue/18234-dollar-idents branch from 3fe96a5 to 9754e00Compare
| caseGivenSyntaxextendsMigrationVersion(future, future) | ||
| caseImplicitParamsWithoutUsingextendsMigrationVersion(`3.7`, future) | ||
| caseScala2ImplicitsextendsMigrationVersion(future, future) | ||
| caseIdentifierDollarsextendsMigrationVersion(`3.8`, `3.9`) |
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@Gedochao What's the warning policy for the feature freeze?
Should this be
| caseIdentifierDollarsextendsMigrationVersion(`3.8`, `3.9`) | |
| caseIdentifierDollarsextendsMigrationVersion(`3.10`, `3.11`) |
at this point?
Or can we get away with
| caseIdentifierDollarsextendsMigrationVersion(`3.8`, `3.9`) | |
| caseIdentifierDollarsextendsMigrationVersion(`3.8`, `3.10`) |
even though the warning would then be introduced in a patch version?
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my gut says the former (3.10, 3.11), but I probably could be convinced otherwise.
We haven't had a precedent for this, I guess.
let's discuss it on today's Scala Core.
| if checkable && name.toSimpleName.contains('$') then | ||
| report.errorOrMigrationWarning(IllegalIdentifier(name), start, MigrationVersion.IdentifierDollars) | ||
| extension (nameTree: NameTree) defcheckName: nameTree.type= |
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Sometimes this method is called as a function, sometimes as an extension. That's confusing. Given that you sometimes need it just for the side effect, consider standardizing on the function variant:
| extension(nameTree: NameTree)defcheckName: nameTree.type= | |
| defcheckName(nameTree: NameTree): nameTree.type= |
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I will consider it. This was my first opportunity to use an extension "both ways", which I think is a feature of extensions.
Gedochao added the stat:needs decision 3 participants
Warns on definitions named with embedded dollars, which
shouldmust be written in backquotes, if at all.Fixes#18234
Test from #18563