diff options
author | Jason Zaugg <jzaugg@gmail.com> | 2013-01-31 00:33:19 +0100 |
---|---|---|
committer | Jason Zaugg <jzaugg@gmail.com> | 2013-02-07 21:58:47 +0100 |
commit | 55c9b9c280ac9bc36bbac09397c7646f8dcf4583 (patch) | |
tree | cdfc1cd396eaba78f0150968634722bcb8df8bd7 /test/files/run/t6146b.check | |
parent | 81d8f9d3da656cfb05f125ba7cf70ca51a477240 (diff) | |
download | scala-55c9b9c280ac9bc36bbac09397c7646f8dcf4583.tar.gz scala-55c9b9c280ac9bc36bbac09397c7646f8dcf4583.tar.bz2 scala-55c9b9c280ac9bc36bbac09397c7646f8dcf4583.zip |
SI-6146 More accurate prefixes for sealed subtypes.
When analysing exhaustivity/reachability of type tests
and equality tests, the pattern matcher must construct
a set of sealed subtypes based on the prefix of the
static type of and the set of sealed descendent symbols
of that type.
Previously, it was using `memberType` for this purpose.
In simple cases, this is sufficient:
scala> class C { class I1; object O { class I2 } }; object D extends C
defined class C
defined module D
scala> typeOf[D.type] memberType typeOf[C#I1].typeSymbol
res0: u.Type = D.I1
But, as reported in this bug, it fails when there is an
additional level of nesting:
scala> typeOf[D.type] memberType typeOf[c.O.I2 forSome { val c: C }].typeSymbol
res5: u.Type = C.O.I2
This commit introduces `nestedMemberType`, which uses `memberType`
recursively up the prefix chain prefix chain.
scala> nestedMemberType(typeOf[c.O.I2 forSome { val c: C }].typeSymbol, typeOf[D.type], typeOf[C].typeSymbol)
res6: u.Type = D.O.Id
Diffstat (limited to 'test/files/run/t6146b.check')
-rw-r--r-- | test/files/run/t6146b.check | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/test/files/run/t6146b.check b/test/files/run/t6146b.check new file mode 100644 index 0000000000..b664d1152a --- /dev/null +++ b/test/files/run/t6146b.check @@ -0,0 +1,52 @@ +Type in expressions to have them evaluated. +Type :help for more information. + +scala> :power +** Power User mode enabled - BEEP WHIR GYVE ** +** :phase has been set to 'typer'. ** +** scala.tools.nsc._ has been imported ** +** global._, definitions._ also imported ** +** Try :help, :vals, power.<tab> ** + +scala> val u = rootMirror.universe; import u._, language._ +u: $r.intp.global.type = <global> +import u._ +import language._ + +scala> val S1 = typeOf[c.X.S1.type forSome { val c: C[_] }].typeSymbol.tpeHK +S1: u.Type = C.X.S1.type + +scala> val S2 = typeOf[O.S2].typeSymbol.tpeHK +S2: u.Type = C.this.S2 + +scala> val S3 = typeOf[O.S3].typeSymbol.tpeHK +S3: u.Type = O.S3 + +scala> val S4 = typeOf[S4].typeSymbol.tpeHK +S4: u.Type = S4 + +scala> val F = typeOf[c.F[_] forSome { val c: C[_] }].typeSymbol.tpeHK +F: u.Type = C.this.F + +scala> val fTpe = typeOf[O.type].decl(newTermName("foo")).paramss.head.head.tpe +fTpe: u.Type = O.F[Int] + +scala> def memType(sub: Type, scrut: Type): Type = + nestedMemberType(sub.typeSymbol, scrut.prefix, scrut.typeSymbol.owner) +memType: (sub: u.Type, scrut: u.Type)u.Type + +scala> + +scala> memType(S1, fTpe) +res0: u.Type = O.X.S1.type + +scala> memType(S2, fTpe) +res1: u.Type = O.S2 + +scala> memType(S3, fTpe) +res2: u.Type = O.S3 + +scala> memType(S4, fTpe) +res3: u.Type = S4 + +scala> |