Skip to content

enable bounds checking for match types #24316

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
wants to merge 1 commit into
base: main
Choose a base branch
from
Draft

enable bounds checking for match types #24316

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
9 changes: 0 additions & 9 deletions compiler/src/dotty/tools/dotc/transform/PostTyper.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -667,15 +667,6 @@ class PostTyper extends MacroTransform with InfoTransformer { thisPhase =>
// case x: Tree[?]
// (which translates to)
// case x: (_: Tree[?])
case m @ MatchTypeTree(bounds, selector, cases) =>
// Analog to the case above for match types
def transformIgnoringBoundsCheck(x: CaseDef): CaseDef =
withMode(Mode.Pattern)(super.transform(x)).asInstanceOf[CaseDef]
cpy.MatchTypeTree(tree)(
super.transform(bounds),
super.transform(selector),
cases.mapConserve(transformIgnoringBoundsCheck)
)
case Block(_, Closure(_, _, tpt)) if ExpandSAMs.needsWrapperClass(tpt.tpe) =>
superAcc.withInvalidCurrentClass(super.transform(tree))
case tree: RefinedTypeTree =>
Expand Down
6 changes: 6 additions & 0 deletions tests/neg/i24313.check
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,6 @@
-- [E057] Type Mismatch Error: tests/neg/i24313.scala:4:14 -------------------------------------------------------------
4 | case _ => S[String] // error
| ^
| Type argument String does not conform to upper bound Int
|
| longer explanation available when compiling with `-explain`
4 changes: 4 additions & 0 deletions tests/neg/i24313.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,4 @@
type S[N <: Int]

type Foo[Xs] = Xs match
case _ => S[String] // error
Loading