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author | Samuel Gruetter <samuel.gruetter@epfl.ch> | 2014-03-12 22:44:33 +0100 |
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committer | Samuel Gruetter <samuel.gruetter@epfl.ch> | 2014-03-12 22:44:33 +0100 |
commit | 9ef5f6817688f814a3450126aa7383b0928e80a0 (patch) | |
tree | 5727a2f7f7fd665cefdb312af2785c692f04377c /tests/untried/pos/tcpoly_ticket2096.scala | |
parent | 194be919664447631ba55446eb4874979c908d27 (diff) | |
download | dotty-9ef5f6817688f814a3450126aa7383b0928e80a0.tar.gz dotty-9ef5f6817688f814a3450126aa7383b0928e80a0.tar.bz2 dotty-9ef5f6817688f814a3450126aa7383b0928e80a0.zip |
add tests from scala/test/files/{pos,neg}
with explicit Unit return type
Diffstat (limited to 'tests/untried/pos/tcpoly_ticket2096.scala')
-rw-r--r-- | tests/untried/pos/tcpoly_ticket2096.scala | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/tests/untried/pos/tcpoly_ticket2096.scala b/tests/untried/pos/tcpoly_ticket2096.scala new file mode 100644 index 000000000..d2387b36b --- /dev/null +++ b/tests/untried/pos/tcpoly_ticket2096.scala @@ -0,0 +1,30 @@ +// smallest expression of monad i can find +trait MBrace[C[X] <: MBrace[C,X],A] { + def nest( a : A ) : C[A] + def flatten[T <: C[C[A]]]( bsq : T ) : C[A] +} + +// a monad that is a Seq +trait MBraceSeq[C[X] <: MBrace[C,X] with Seq[X],A] extends MBrace[C,A] + +// one of the simplest witnesses of monad i can find +case class MSequitor[A]( a_ : A* ) extends Seq[A] with MBrace[MSequitor,A] +{ + override def nest( a : A ) = new MSequitor[A]( a ) + override def flatten[T <: MSequitor[MSequitor[A]]]( bsq : T ) : MSequitor[A] = { + (new MSequitor[A]( ) /: bsq)( { + ( acc : MSequitor[A], e : MSequitor[A] ) => ( acc ++ e ).asInstanceOf[MSequitor[A]] + } ) + } + override def length = a_.length + override def iterator = a_.iterator + override def apply( n : Int ) = a_.apply( n ) +} + +// type arguments [MSequitor,A] do not conform to trait MBraceSeq's type parameter bounds [C[_] <: MBrace[C,A] with Seq[A],A] +// a statement of the instance relation +class MBraceSequitor[A] extends MBraceSeq[MSequitor,A] { + val empty : MSequitor[A] = new MSequitor[A]( ) + override def nest( a : A ) = empty.nest( a ) + override def flatten[T <: MSequitor[MSequitor[A]]]( bsq : T ): MSequitor[A] = empty.flatten( bsq ) +} |