Fix #1857: Allow lower bounds to influence implicit search #3921
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The previous implementation claimed to conform to the spec:
We exclude lower bounds to conform to SLS 7.2:
"The parts of a type T are: [...] if T is an abstract type, the parts of its upper bound"
But in fact we do not need to exclude lower bounds from `namedPartsWith` to do that -
TypeRefs are already lifted to classes, which implements SLS 7.2. Including lower bounds
does affect wildcard types (i1857.scala) and wildcard parameters in implicits (implicit-lower-bound.scala),
but the spec does not exclude either if these.
odersky
changed the title
|
Test optimized hung. It's doing that a lot now. Can we find out the root cause of this? |
smarter
reviewed
Feb 3, 2018
| get1 // works | ||
| get2 // error | ||
| get1 | ||
| get2 |
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I'll note that this line doesn't compile with scalac, so scalac interpretation of SLS 7.2 seems to match what I had in mind.
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The previous implementation claimed to conform to the spec:
But in fact we do not need to exclude lower bounds from
namedPartsWithto do that -TypeRefs are already lifted to classes, which implements SLS 7.2. Including lower bounds
does affect wildcard types (i1857.scala) and wildcard parameters in implicits (implicit-lower-bound.scala), but the spec does not exclude either of these.