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EugeneFlesselleEugeneFlesselle
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Update check-files and error annotations
The diff in neg/10349.scala is quite interesting. With a few intermediate values: ```scala type First[X] = X match case Map[_, v] => First[Option[v]] def first[X](x: X): First[X] = x match case x: Map[k, v] => val hdOpt: Option[v] = x.values.headOption first(hdOpt): First[Option[v]] // error only before changes ``` This now type-checks but will fail at runtime because of the in-exhaustivity of the match expression. Perhaps we should add some additional condition in `isMatchTypeShaped` to account for this, or at least emit a warning ?
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-98
lines changed

8 files changed

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‎compiler/src/dotty/tools/dotc/core/TypeComparer.scala

Lines changed: 4 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -3594,6 +3594,10 @@ class MatchReducer(initctx: Context) extends TypeComparer(initctx) {
35943594
MatchTypeTrace.emptyScrutinee(scrut)
35953595
NoType
35963596
case Nil =>
3597+
/* TODO warn ? then re-enable warn/12974.scala:26
3598+
val noCasesText = MatchTypeTrace.noMatchesText(scrut, cases)
3599+
report.warning(reporting.MatchTypeNoCases(noCasesText), pos = ???)
3600+
*/
35973601
MatchTypeTrace.noMatches(scrut, cases)
35983602
NoType
35993603

‎tests/neg-macros/toexproftuple.scala

Lines changed: 4 additions & 57 deletions
Original file line numberDiff line numberDiff line change
@@ -1,63 +1,10 @@
1-
import scala.quoted._, scala.deriving.* // error
2-
// ^
3-
// Match type reduction failed since selector ((2 : Int), quoted.Expr[(3 : Int)])
4-
// matches none of the cases
5-
//
6-
// case quoted.Expr[x] *: t => x *: scala.Tuple.InverseMap[t, quoted.Expr]
7-
// case EmptyTuple => EmptyTuple
8-
9-
inline def mcr: Any = ${mcrImpl} // error
10-
// ^
11-
// Match type reduction failed since selector ((2 : Int), quoted.Expr[(3 : Int)])
12-
// matches none of the cases
13-
//
14-
// case quoted.Expr[x] *: t => x *: scala.Tuple.InverseMap[t, quoted.Expr]
15-
// case EmptyTuple => EmptyTuple
16-
17-
def mcrImpl(using ctx: Quotes): Expr[Any] = { // error // error
18-
//^
19-
// Match type reduction failed since selector ((2 : Int), quoted.Expr[(3 : Int)])
20-
// matches none of the cases
21-
//
22-
// case quoted.Expr[x] *: t => x *: scala.Tuple.InverseMap[t, quoted.Expr]
23-
// case EmptyTuple => EmptyTuple
24-
25-
// ^
26-
// Match type reduction failed since selector ((2 : Int), quoted.Expr[(3 : Int)])
27-
// matches none of the cases
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//
29-
// case quoted.Expr[x] *: t => x *: scala.Tuple.InverseMap[t, quoted.Expr]
30-
// case EmptyTuple => EmptyTuple
1+
import scala.quoted._, scala.deriving.*
312

3+
inline def mcr: Any = ${mcrImpl}
4+
def mcrImpl(using ctx: Quotes): Expr[Any] = {
325
val tpl: (Expr[1], Expr[2], Expr[3]) = ('{1}, '{2}, '{3})
336
'{val res: (1, 3, 3) = ${Expr.ofTuple(tpl)}; res} // error
34-
// ^^^^^^^^^^^^^^^^^
35-
// Found: quoted.Expr[(1 : Int) *: (2 : Int) *: (3 : Int) *: EmptyTuple]
36-
// Required: quoted.Expr[((1 : Int), (3 : Int), (3 : Int))]
377

388
val tpl2: (Expr[1], 2, Expr[3]) = ('{1}, 2, '{3})
39-
'{val res = ${Expr.ofTuple(tpl2)}; res} // error // error // error // error
40-
// ^
41-
// Cannot prove that (quoted.Expr[(1 : Int)], (2 : Int), quoted.Expr[(3 : Int)]) =:= scala.Tuple.Map[
42-
// scala.Tuple.InverseMap[
43-
// (quoted.Expr[(1 : Int)], (2 : Int), quoted.Expr[(3 : Int)])
44-
// , quoted.Expr]
45-
// , quoted.Expr].
46-
47-
// ^
48-
// Match type reduction failed since selector ((2 : Int), quoted.Expr[(3 : Int)])
49-
// matches none of the cases
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//
51-
// case quoted.Expr[x] *: t => x *: scala.Tuple.InverseMap[t, quoted.Expr]
52-
// case EmptyTuple => EmptyTuple
53-
54-
// ^
55-
// Cyclic reference involving val res
56-
57-
// ^
58-
// Match type reduction failed since selector ((2 : Int), quoted.Expr[(3 : Int)])
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// matches none of the cases
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//
61-
// case quoted.Expr[x] *: t => x *: scala.Tuple.InverseMap[t, quoted.Expr]
62-
// case EmptyTuple => EmptyTuple
9+
'{val res = ${Expr.ofTuple(tpl2)}; res} // error
6310
}

‎tests/neg/10349.scala

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -4,7 +4,7 @@ object Firsts:
44
case Map[_, v] => First[Option[v]]
55

66
def first[X](x: X): First[X] = x match
7-
case x: Map[_, _] => first(x.values.headOption) // error
7+
case x: Map[_, _] => first(x.values.headOption)
88

99
@main
1010
def runFirsts2(): Unit =

‎tests/neg/10747.scala

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -2,4 +2,5 @@ type Foo[A] = A match {
22
case Int => String
33
}
44

5-
type B = Foo[Boolean] // error
5+
type B = Foo[Boolean]
6+
val _: B = "hello" // error

‎tests/neg/i12049.check

Lines changed: 64 additions & 24 deletions
Original file line numberDiff line numberDiff line change
@@ -15,22 +15,45 @@
1515
| case B => String
1616
|
1717
| longer explanation available when compiling with `-explain`
18-
-- Error: tests/neg/i12049.scala:14:23 ---------------------------------------------------------------------------------
18+
-- [E007] Type Mismatch Error: tests/neg/i12049.scala:14:17 ------------------------------------------------------------
1919
14 |val y3: String = ??? : Last[Int *: Int *: Boolean *: String *: EmptyTuple] // error
20-
| ^
21-
| Match type reduction failed since selector EmptyTuple
22-
| matches none of the cases
20+
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
21+
| Found: Last[EmptyTuple]
22+
| Required: String
2323
|
24-
| case _ *: _ *: t => Last[t]
25-
| case t *: EmptyTuple => t
26-
-- Error: tests/neg/i12049.scala:22:26 ---------------------------------------------------------------------------------
24+
| Note: a match type could not be fully reduced:
25+
|
26+
| trying to reduce Last[EmptyTuple]
27+
| failed since selector EmptyTuple
28+
| matches none of the cases
29+
|
30+
| case _ *: _ *: t => Last[t]
31+
| case t *: EmptyTuple => t
32+
|
33+
| longer explanation available when compiling with `-explain`
34+
-- [E007] Type Mismatch Error: tests/neg/i12049.scala:22:20 ------------------------------------------------------------
2735
22 |val z3: (A, B, A) = ??? : Reverse[(A, B, A)] // error
28-
| ^
29-
| Match type reduction failed since selector A *: EmptyTuple.type
30-
| matches none of the cases
36+
| ^^^^^^^^^^^^^^^^^^^^^^^^
37+
| Found: Tuple.Concat[Reverse[A *: EmptyTuple.type], (B, A)]
38+
| Required: (A, B, A)
39+
|
40+
| Note: a match type could not be fully reduced:
41+
|
42+
| trying to reduce Tuple.Concat[Reverse[A *: EmptyTuple.type], (B, A)]
43+
| trying to reduce Reverse[A *: EmptyTuple.type]
44+
| failed since selector A *: EmptyTuple.type
45+
| matches none of the cases
46+
|
47+
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
48+
| case EmptyTuple => EmptyTuple
49+
| trying to reduce Reverse[A *: EmptyTuple.type]
50+
| failed since selector A *: EmptyTuple.type
51+
| matches none of the cases
3152
|
32-
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
33-
| case EmptyTuple => EmptyTuple
53+
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
54+
| case EmptyTuple => EmptyTuple
55+
|
56+
| longer explanation available when compiling with `-explain`
3457
-- [E172] Type Error: tests/neg/i12049.scala:24:20 ---------------------------------------------------------------------
3558
24 |val _ = summon[M[B]] // error
3659
| ^
@@ -45,22 +68,39 @@
4568
| Therefore, reduction cannot advance to the remaining case
4669
|
4770
| case B => String
48-
-- Error: tests/neg/i12049.scala:25:26 ---------------------------------------------------------------------------------
71+
-- [E172] Type Error: tests/neg/i12049.scala:25:78 ---------------------------------------------------------------------
4972
25 |val _ = summon[String =:= Last[Int *: Int *: Boolean *: String *: EmptyTuple]] // error
50-
| ^
51-
| Match type reduction failed since selector EmptyTuple
52-
| matches none of the cases
73+
| ^
74+
| Cannot prove that String =:= Last[EmptyTuple].
75+
|
76+
| Note: a match type could not be fully reduced:
77+
|
78+
| trying to reduce Last[EmptyTuple]
79+
| failed since selector EmptyTuple
80+
| matches none of the cases
5381
|
54-
| case _ *: _ *: t => Last[t]
55-
| case t *: EmptyTuple => t
56-
-- Error: tests/neg/i12049.scala:26:29 ---------------------------------------------------------------------------------
82+
| case _ *: _ *: t => Last[t]
83+
| case t *: EmptyTuple => t
84+
-- [E172] Type Error: tests/neg/i12049.scala:26:48 ---------------------------------------------------------------------
5785
26 |val _ = summon[(A, B, A) =:= Reverse[(A, B, A)]] // error
58-
| ^
59-
| Match type reduction failed since selector A *: EmptyTuple.type
60-
| matches none of the cases
86+
| ^
87+
| Cannot prove that (A, B, A) =:= Tuple.Concat[Reverse[A *: EmptyTuple.type], (B, A)].
88+
|
89+
| Note: a match type could not be fully reduced:
90+
|
91+
| trying to reduce Tuple.Concat[Reverse[A *: EmptyTuple.type], (B, A)]
92+
| trying to reduce Reverse[A *: EmptyTuple.type]
93+
| failed since selector A *: EmptyTuple.type
94+
| matches none of the cases
95+
|
96+
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
97+
| case EmptyTuple => EmptyTuple
98+
| trying to reduce Reverse[A *: EmptyTuple.type]
99+
| failed since selector A *: EmptyTuple.type
100+
| matches none of the cases
61101
|
62-
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
63-
| case EmptyTuple => EmptyTuple
102+
| case t1 *: t2 *: ts => Tuple.Concat[Reverse[ts], (t2, t1)]
103+
| case EmptyTuple => EmptyTuple
64104
-- [E008] Not Found Error: tests/neg/i12049.scala:28:21 ----------------------------------------------------------------
65105
28 |val _ = (??? : M[B]).length // error
66106
| ^^^^^^^^^^^^^^^^^^^

‎tests/neg/i13757-match-type-anykind.scala

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,9 +8,9 @@ object Test:
88
type AnyKindMatchType3[X <: AnyKind] = X match // error: the scrutinee of a match type cannot be higher-kinded
99
case _ => Int
1010

11-
type AnyKindMatchType4[X <: Option] = X match // error // error: the scrutinee of a match type cannot be higher-kinded // error
11+
type AnyKindMatchType4[X <: Option] = X match // error // error: the scrutinee of a match type cannot be higher-kinded
1212
case _ => Int
1313

14-
type AnyKindMatchType5[X[_]] = X match // error: the scrutinee of a match type cannot be higher-kinded // error
14+
type AnyKindMatchType5[X[_]] = X match // error: the scrutinee of a match type cannot be higher-kinded
1515
case _ => Int
1616
end Test

‎tests/neg/matchtype-seq.check

Lines changed: 28 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -1,19 +1,35 @@
1-
-- Error: tests/neg/matchtype-seq.scala:9:11 ---------------------------------------------------------------------------
1+
-- [E007] Type Mismatch Error: tests/neg/matchtype-seq.scala:9:18 ------------------------------------------------------
22
9 | identity[T1[3]]("") // error
3-
| ^
4-
| Match type reduction failed since selector (3 : Int)
5-
| matches none of the cases
3+
| ^^
4+
| Found: ("" : String)
5+
| Required: Test.T1[(3 : Int)]
66
|
7-
| case (1 : Int) => Int
8-
| case (2 : Int) => String
9-
-- Error: tests/neg/matchtype-seq.scala:10:11 --------------------------------------------------------------------------
7+
| Note: a match type could not be fully reduced:
8+
|
9+
| trying to reduce Test.T1[(3 : Int)]
10+
| failed since selector (3 : Int)
11+
| matches none of the cases
12+
|
13+
| case (1 : Int) => Int
14+
| case (2 : Int) => String
15+
|
16+
| longer explanation available when compiling with `-explain`
17+
-- [E007] Type Mismatch Error: tests/neg/matchtype-seq.scala:10:18 -----------------------------------------------------
1018
10 | identity[T1[3]](1) // error
11-
| ^
12-
| Match type reduction failed since selector (3 : Int)
13-
| matches none of the cases
19+
| ^
20+
| Found: (1 : Int)
21+
| Required: Test.T1[(3 : Int)]
1422
|
15-
| case (1 : Int) => Int
16-
| case (2 : Int) => String
23+
| Note: a match type could not be fully reduced:
24+
|
25+
| trying to reduce Test.T1[(3 : Int)]
26+
| failed since selector (3 : Int)
27+
| matches none of the cases
28+
|
29+
| case (1 : Int) => Int
30+
| case (2 : Int) => String
31+
|
32+
| longer explanation available when compiling with `-explain`
1733
-- [E007] Type Mismatch Error: tests/neg/matchtype-seq.scala:11:20 -----------------------------------------------------
1834
11 | identity[T1[Int]]("") // error
1935
| ^^

‎tests/neg/12974.scala renamed to ‎tests/warn/12974.scala

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -23,7 +23,7 @@ object RecMap {
2323
def main(args: Array[String]) =
2424
import Record._
2525

26-
val foo: Any = Rec.empty.fetch("foo") // error
26+
val foo: Any = Rec.empty.fetch("foo") // TODO
2727
// ^
2828
// Match type reduction failed since selector EmptyTuple.type
2929
// matches none of the cases

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