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| author | Martin Odersky <odersky@gmail.com> | 2015-09-24 16:43:40 +0200 |
|---|---|---|
| committer | Martin Odersky <odersky@gmail.com> | 2015-10-01 19:34:14 +0200 |
| commit | 241065192926524292f950288518533429297666 (patch) | |
| tree | d2b6ff0d5c6cf7b0146ac5bb3a68f7f40a9242dd /src | |
| parent | 2d6d432001bb237897918a05bd3e82be87dc8a11 (diff) | |
| download | dotty-241065192926524292f950288518533429297666.tar.gz dotty-241065192926524292f950288518533429297666.tar.bz2 dotty-241065192926524292f950288518533429297666.zip | |
Freeze constraints when checking parameter matching and subsumption.
Checking whether two alternatives are the same should not unify
them by instantiating type variables.
Diffstat (limited to 'src')
| -rw-r--r-- | src/dotty/tools/dotc/core/ConstraintHandling.scala | 8 | ||||
| -rw-r--r-- | src/dotty/tools/dotc/core/TypeComparer.scala | 6 |
2 files changed, 11 insertions, 3 deletions
diff --git a/src/dotty/tools/dotc/core/ConstraintHandling.scala b/src/dotty/tools/dotc/core/ConstraintHandling.scala index 6f0377a4d..577b958c8 100644 --- a/src/dotty/tools/dotc/core/ConstraintHandling.scala +++ b/src/dotty/tools/dotc/core/ConstraintHandling.scala @@ -23,6 +23,7 @@ trait ConstraintHandling { implicit val ctx: Context protected def isSubType(tp1: Type, tp2: Type): Boolean + protected def isSameType(tp1: Type, tp2: Type): Boolean val state: TyperState import state.constraint @@ -111,6 +112,13 @@ trait ConstraintHandling { finally frozenConstraint = saved } + final def isSameTypeWhenFrozen(tp1: Type, tp2: Type): Boolean = { + val saved = frozenConstraint + frozenConstraint = true + try isSameType(tp1, tp2) + finally frozenConstraint = saved + } + /** Test whether the lower bounds of all parameters in this * constraint are a solution to the constraint. */ diff --git a/src/dotty/tools/dotc/core/TypeComparer.scala b/src/dotty/tools/dotc/core/TypeComparer.scala index 8b2eb9cbf..59d4898e6 100644 --- a/src/dotty/tools/dotc/core/TypeComparer.scala +++ b/src/dotty/tools/dotc/core/TypeComparer.scala @@ -685,7 +685,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { case formal1 :: rest1 => formals2 match { case formal2 :: rest2 => - (isSameType(formal1, formal2) + (isSameTypeWhenFrozen(formal1, formal2) || isJava1 && (formal2 isRef ObjectClass) && (formal1 isRef AnyClass) || isJava2 && (formal1 isRef ObjectClass) && (formal2 isRef AnyClass)) && matchingParams(rest1, rest2, isJava1, isJava2) @@ -1059,7 +1059,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { case tp1: ClassInfo => tp2 match { case tp2: ClassInfo => - isSubType(tp1.prefix, tp2.prefix) || (tp1.cls.owner derivesFrom tp2.cls.owner) + isSubTypeWhenFrozen(tp1.prefix, tp2.prefix) || (tp1.cls.owner derivesFrom tp2.cls.owner) case _ => false } @@ -1075,7 +1075,7 @@ class TypeComparer(initctx: Context) extends DotClass with ConstraintHandling { tp2 match { case tp2: MethodType => def asGoodParams(formals1: List[Type], formals2: List[Type]) = - (formals2 corresponds formals1)(isSubType) + (formals2 corresponds formals1)(isSubTypeWhenFrozen) asGoodParams(tp1.paramTypes, tp2.paramTypes) && (!asGoodParams(tp2.paramTypes, tp1.paramTypes) || isAsGood(tp1.resultType, tp2.resultType)) |