Fix #2152: Instantiate dependent result type parameters#2209
Merged
odersky merged 2 commits intoscala:masterfrom Apr 13, 2017
Merged
Fix #2152: Instantiate dependent result type parameters#2209odersky merged 2 commits intoscala:masterfrom
odersky merged 2 commits intoscala:masterfrom
Conversation
Contributor
|
I can confirm that this fixes the issue I described (in reduced form) in #2152. |
smarter
approved these changes
Apr 11, 2017
Member
smarter
left a comment
smarter
left a comment
There was a problem hiding this comment.
Needs to be rebased, otherwise LGTM.
scala#2152 shows that dependent result type parameters can end up in the types of terms, so we have to eliminate them. If we don't we get orphan parameters in pickling. Fix method name and comment
The original fix made run/hmap-covariant fail because a type variable representing a dependent result parameter was instantiated. Trying something else now.
Contributor
Author
|
@propensive Can you please check whether the latest commit also solves the original issue you were having? Unfortunately my original fix broke something else. |
smarter
added a commit
to dotty-staging/dotty
that referenced
this pull request
May 21, 2020
`TypeOps#simplify` is supposed to produce a type `=:=` the original type, but it replaced type variables created using `newTypeVar` by one of their bound, this is wrong since that type variable might get instantiated to a different type later. This simplification was added in scala#2209 to prevent a pickling crash in tests/pos/i2152.scala but does not appear to be needed anymore: an uninstantiated type variable being preserved after typer is always wrong, so the underlying bug must have been fixed since then.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
3 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
#2152 shows that dependent result type parameters can end up in
the types of terms, so we have to eliminate them. If we don't we
get orphan parameters in pickling.
Based on #2128. Only one commit is new.