Skip to content
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

Fix match type reduction with wildcard type arguments #17065

Merged
merged 2 commits into from
Mar 7, 2023
Merged

Fix match type reduction with wildcard type arguments #17065

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
9b15b2e
Remove extra spaces in error messages
mbovel Mar 7, 2023
50ff047
Consider TypeBounds not fully instantiated
mbovel Mar 7, 2023
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
10 changes: 5 additions & 5 deletions compiler/src/dotty/tools/dotc/core/MatchTypeTrace.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -100,16 +100,16 @@ object MatchTypeTrace:
case TryReduce(scrut: Type) =>
i" trying to reduce $scrut"
case NoMatches(scrut, cases) =>
i""" failed since selector $scrut
i""" failed since selector $scrut
| matches none of the cases
|
| ${casesText(cases)}"""
case EmptyScrutinee(scrut) =>
i""" failed since selector $scrut
i""" failed since selector $scrut
| is uninhabited (there are no values of that type)."""
case Stuck(scrut, stuckCase, otherCases) =>
val msg =
i""" failed since selector $scrut
i""" failed since selector $scrut
| does not match ${caseText(stuckCase)}
| and cannot be shown to be disjoint from it either."""
if otherCases.length == 0 then msg
Expand All @@ -121,14 +121,14 @@ object MatchTypeTrace:
| ${casesText(otherCases)}"""
case NoInstance(scrut, stuckCase, fails) =>
def params = if fails.length == 1 then "parameter" else "parameters"
i""" failed since selector $scrut
i""" failed since selector $scrut
| does not uniquely determine $params ${fails.map(_._1)}%, % in
| ${caseText(stuckCase)}
| The computed bounds for the $params are:
| ${fails.map((name, bounds) => i"$name$bounds")}%\n %"""

def noMatchesText(scrut: Type, cases: List[Type])(using Context): String =
i"""failed since selector $scrut
i"""failed since selector $scrut
|matches none of the cases
|
| ${casesText(cases)}"""
Expand Down
2 changes: 1 addition & 1 deletion compiler/src/dotty/tools/dotc/core/TypeComparer.scala
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2725,7 +2725,7 @@ class TypeComparer(@constructorOnly initctx: Context) extends ConstraintHandling
x && {
t.dealias match {
case tp: TypeRef if !tp.symbol.isClass => false
case _: SkolemType | _: TypeVar | _: TypeParamRef => false
case _: SkolemType | _: TypeVar | _: TypeParamRef | _: TypeBounds => false
case _ => foldOver(x, t)
}
}
Expand Down
4 changes: 2 additions & 2 deletions tests/neg/6570-1.check
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce N[Box[Int & String]]
| failed since selector Box[Int & String]
| failed since selector Box[Int & String]
| is uninhabited (there are no values of that type).
|
| longer explanation available when compiling with `-explain`
Expand All @@ -23,7 +23,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce M[T]
| failed since selector T
| failed since selector T
| does not uniquely determine parameter x in
| case Cov[x] => N[x]
| The computed bounds for the parameter are:
Expand Down
4 changes: 2 additions & 2 deletions tests/neg/6571.check
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Test.M[Test.Inv[Int] & Test.Inv[String]]
| failed since selector Test.Inv[Int] & Test.Inv[String]
| failed since selector Test.Inv[Int] & Test.Inv[String]
| is uninhabited (there are no values of that type).
|
| longer explanation available when compiling with `-explain`
Expand All @@ -20,7 +20,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Test.M[Test.Inv[String] & Test.Inv[Int]]
| failed since selector Test.Inv[String] & Test.Inv[Int]
| failed since selector Test.Inv[String] & Test.Inv[Int]
| is uninhabited (there are no values of that type).
|
| longer explanation available when compiling with `-explain`
6 changes: 3 additions & 3 deletions tests/neg/i11982a.check
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -6,7 +6,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Tuple.Tail[X]
| failed since selector X
| failed since selector X
| does not uniquely determine parameter xs in
| case _ *: xs => xs
| The computed bounds for the parameter are:
Expand All @@ -21,7 +21,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Tuple.Tail[X]
| failed since selector X
| failed since selector X
| does not uniquely determine parameter xs in
| case _ *: xs => xs
| The computed bounds for the parameter are:
Expand All @@ -36,7 +36,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Tuple.Tail[X]
| failed since selector X
| failed since selector X
| does not uniquely determine parameter xs in
| case _ *: xs => xs
| The computed bounds for the parameter are:
Expand Down
14 changes: 7 additions & 7 deletions tests/neg/i12049.check
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -7,7 +7,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce M[B]
| failed since selector B
| failed since selector B
| does not match case A => Int
| and cannot be shown to be disjoint from it either.
| Therefore, reduction cannot advance to the remaining case
Expand All @@ -18,15 +18,15 @@
-- Error: tests/neg/i12049.scala:14:23 ---------------------------------------------------------------------------------
14 |val y3: String = ??? : Last[Int *: Int *: Boolean *: String *: EmptyTuple] // error
| ^
| Match type reduction failed since selector EmptyTuple.type
| Match type reduction failed since selector EmptyTuple.type
| matches none of the cases
|
| case _ *: _ *: t => Last[t]
| case t *: EmptyTuple => t
-- Error: tests/neg/i12049.scala:22:26 ---------------------------------------------------------------------------------
22 |val z3: (A, B, A) = ??? : Reverse[(A, B, A)] // error
| ^
| Match type reduction failed since selector A *: EmptyTuple.type
| Match type reduction failed since selector A *: EmptyTuple.type
| matches none of the cases
|
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
Expand All @@ -39,7 +39,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce M[B]
| failed since selector B
| failed since selector B
| does not match case A => Int
| and cannot be shown to be disjoint from it either.
| Therefore, reduction cannot advance to the remaining case
Expand All @@ -48,15 +48,15 @@
-- Error: tests/neg/i12049.scala:25:26 ---------------------------------------------------------------------------------
25 |val _ = summon[String =:= Last[Int *: Int *: Boolean *: String *: EmptyTuple]] // error
| ^
| Match type reduction failed since selector EmptyTuple.type
| Match type reduction failed since selector EmptyTuple.type
| matches none of the cases
|
| case _ *: _ *: t => Last[t]
| case t *: EmptyTuple => t
-- Error: tests/neg/i12049.scala:26:29 ---------------------------------------------------------------------------------
26 |val _ = summon[(A, B, A) =:= Reverse[(A, B, A)]] // error
| ^
| Match type reduction failed since selector A *: EmptyTuple.type
| Match type reduction failed since selector A *: EmptyTuple.type
| matches none of the cases
|
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
Expand All @@ -69,7 +69,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce M[B]
| failed since selector B
| failed since selector B
| does not match case A => Int
| and cannot be shown to be disjoint from it either.
| Therefore, reduction cannot advance to the remaining case
Expand Down
4 changes: 2 additions & 2 deletions tests/neg/i13780.check
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Head[X]
| failed since selector X
| failed since selector X
| does not uniquely determine parameters a, b in
| case (a, b) => a
| The computed bounds for the parameters are:
Expand All @@ -30,7 +30,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce Head[X]
| failed since selector X
| failed since selector X
| does not uniquely determine parameters a, b in
| case (a, b) => a
| The computed bounds for the parameters are:
Expand Down
2 changes: 1 addition & 1 deletion tests/neg/i15618.check
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -9,7 +9,7 @@
| Note: a match type could not be fully reduced:
|
| trying to reduce ScalaType[T]
| failed since selector T
| failed since selector T
| does not match case Float16 => Float
| and cannot be shown to be disjoint from it either.
| Therefore, reduction cannot advance to the remaining cases
Expand Down
Loading