Fix #9103: Fix implicit scopes #9119
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The idea of LazyRefs is that they are always completed in the current context. But that did not work if the LazyRef is mapped in a type map. Here, the TypeMap's context was used to do the remap. We now use the context that forced the LazyVal instead. The problem manifested itself with failing replTests when the new implicitScope scheme was used.
Compute anchors directly instead of relying on namedPartsWith. This gives more precise control for what is part of the implicit scope.
In that way, we include all of the implicit scope of Scala 2, except for package objects. The idea is that everything that is reasonable should be included in the implicit scope. Package objects were excluded since they had a dual purpose: 1. as a way to define implicits that are in scope for a whole project 2. as a prefix for implicits of all types coming out of that project It's often that one wants only (1) but then is surprised to also get (2). # Conflicts: # compiler/src/dotty/tools/dotc/typer/Implicits.scala # tests/pos/i9103.scala
odersky
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@milessabin I had to disable two places in shapeless that failed after the changes in this PR. Once was the derives clause for |
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test performance please |
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performance test scheduled: 1 job(s) in queue, 0 running. |
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Performance test finished successfully: Visit http://dotty-bench.epfl.ch/9119/ to see the changes. Benchmarks is based on merging with master (345c8bc) |
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@milessabin I might have found the issue: The missing elements are associated with match types. I'll see whether I can fix that. |
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All good now. Shapeless compiles without changes. |
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@anatoliykmetyuk It would be good to get this into 0.25, since it changes search implicit behavior, could potentially introduce errors in code using the old behavior. |
| && tp.hash != NotCached | ||
| && !provisional | ||
| && (tp eq rootTp) // first type traversed is always cached | ||
| || !incomplete.contains(tp) // other types are cached if they are not incomplete |
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A pair of parentheses are missing here, which means this last condition is top-level, that is: all types that are not incomplete are cached, even if:
- Config.cacheImplicitScopes is false, or
- the types hash is NotCached, or
- the type is provisional
Clarify implicit scope rules and implement accordingly.
Fixes #9103
Fixes #9094