Fix incorrect warning on type ascription for backquoted identifiers #23088
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| val p = pattern2(location) | ||
| if in.isColon then | ||
| val isVariableOrNumber = isVarPattern(p) || p.isInstanceOf[Number] | ||
| val isVariableOrNumber = isVarPattern(p) || p.isInstanceOf[Number] || isBackquoted(p) |
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Scala 2 honors the requirement even in backquoting.
scala> 42 match { case `Int`: Int => `Int` }
^
error: Pattern variables must start with a lower-case letter. (SLS 8.1.1.)
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Normal syntax for non-var: 42 match { case X @ (_: Int) => X }
Maybe it's worth adding a neg test.
tests/pos/i22989.scala
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| //> using options -Xfatal-warnings | |||
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| //> using options -Xfatal-warnings | |
| //> using options -Werror |
tests/pos/i15784.scala
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| def i15784_auxiliary = 42 match | ||
| case `type` : Int => `type` | ||
| case _ => ??? |
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You could quiet the other warnings and add the -Werror in the existing file. These directories get large.
By quiet, I'd suggest a def for each "rest" test. (and not just nowarn.)
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Thanks for the review! |
…n patterns address reviews minor fix
| case X: Int => X // warn | ||
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| def case3 = 42 match | ||
| case `Int`: Int => `Int` // warn |
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I don't think the test rig checks the // warn in a neg test, but of course it's verified by the check file. (I'm wondering if the test rig should do that, as an enhancement. I know a difference is that it's OK to have zero warns in a warn test but not OK to have zero errors in a neg test.)
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I see, would it be better if I make a separate tests/warn/i15784.scala?
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No, I think it's fine. Maybe with -Werror you can mark them error. But I was just musing aloud, in case I read this again later.
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As linked above, I got a bonus Scala 2 ticket out of it. |
4 participants
closes #22989